GEOLOGY The person charging this material is re- sponsible for its return to the library from which it was withdrawn on or before the Latest Date stamped below. f. h r e 'dl,r,| ,0,i0n ' r" u "* rt, "'"« »' "OOK, or. re o,.„, z ulrJ:"^ a,,,on ond moy — » - """"»■■ *- To renew call Telephone Center, 333-8400 unhversitt of Illinois library at urbana-champak-.k, Ll«l— O-1096 DO <~^ } THE UPPER ORDOVICIAN FAUNA OF FROBISHER BAY, BAFFIN LAND BY SHARAT KUMAR ROY CURATOR OF GEOLOGY UNIVERSITY & H.LiNPiS GEOLOGY, MEMOIRS FIELD MUSEUM OF NATURAL HISTORY VOLUME 2 SEPTEMBER 30, 1941 THE UPPER ORDOVICIAN FAUNA OF FROBISHER BAY, BAFFIN LAND BY SHARAT KUMAR ROY CURATOR OF GEOLOGY THE UBKARY Of THE NOV 7 1941 UNIVERSITY OF ILLINOIS GEOLOGY, MEMOIRS FIELD MUSEUM OF NATURAL HISTORY VOLUME 2 SEPTEMBER 30, 1941 PRINTED IN THE UNITED STATES OF AMERICA BY FIELD MUSEUM PRESS ;i CONTENTS PAGE List of Illustrations 5 Preface 9 Narrative of the Expedition with Notes on Coastal Geology of Labrador and Baffin Land 13 Introduction 15 Forteau Bay : Raised Beaches and Glacial Striae 15 Icebergs 16 Battle Harbor and Assizes Bay: Lithology and Glacial Striae 16 Aillik Bay: Lithology, Glacial Striae, and Lunoid Markings 16 Labrador Eskimos at Hopedale 18 Roches Moutonnees and Rock Basin Lakes 18 Nain 20 Nain Anorthosite 20 Sculpin Island: Drift Fossils 21 Glacial Striae and Boulder Reefs 23 Naskapi Indians 24 To Frobisher Bay, Cape Mugford, Hudson Strait, and Resolution Island .... 24 Frobisher Bay: Tides 28 Voyages of Sir Martin Frobisher 28 The Discoveries of Charles F. Hall 30 Jackman's Sound, Grinnell Ice-cap, and Everett Range 32 Griffin Bay: Inland Topography 34 Grinnell Ice-cap 34 Newell Sound; Change in Coastal Topography 38 Koojessee Inlet and Sylvia Grinnell River; Baffin Land Eskimos 38 Northern Lights 39 Bishop's Island 40 Silliman's Fossil Mount 40 Fletcher Island and Eskimo Ruins; Glacial Striae 45 Waddell Bay; Fluvio-glacial Deposits 45 Brewster Point; Drift Fossils 45 Kodlunarn Island; Relics of Sir Martin Frobisher 46 Frobisher's "Gold Ore" 48 Lupton Channel 48 Return Journey to Labrador 50 Movement of Boulders by Ice 50 Domed Lakes 52 Ice Mounds 52 "Drift" Snow • 52 "Quor" Water 54 3 4 CONTENTS PAGE Description of Fossils 57 Incertae Sedis 59 Phylum Coelenterata 68 Class Anthozoa 68 Phylum Echinodermata 80 Class Cystoidea 80 Class Crinoidea '. 80 Phylum Molluscoidea 81 Class Bryozoa 81 Class Brachiopoda 84 Phylum Mollusca 106 Class Pelecypoda 106 Class Gastropoda 109 Class Cephalopoda 125 Phylum Arthropoda 152 Class Crustacea 152 Subclass Trilobita 152 Subclass Eucrustacea 169 Superorder Ostracoda 169 Synopsis of Fauna 177 Previous Collections from Silliman's Fossil Mount 182 Age of Silliman's Fossil Mount 189 Bibliography 198 Index 206 LIST OF ILLUSTRATIONS TEXT FIGURES PAGE 1. Map showing route of Rawson-MacMillan Expedition of Field Museum to Labrador and Baffin Land 14 2. Sketch map of Labrador coast 17 3. Icebergs on the coastal waters of Labrador 19 4. Left, roches moutonnSes at Hopedale, Labrador; right, Eskimos paddling out in kayaks 20 5. Rock-basin lakes in the vicinity of Hopedale, Labrador 21 6. Upper Canadian (Beekmantown) drift fossils from Sculpin Island, near Nain, Labrador, a, b, Hormotoma labradorensis Roy; c, Hormoloma minuta Roy; d, Tur- ritoma cf. T. ada (Billings); e, /, g, Helicotoma rawsoni Roy; h, i, Bathyurus sculpinensis Roy; j, Baihyurus{1) sp 22 7. Boulder reef, near Nain, Labrador 23 8. Top left, a Naskapi Indian in traveling gear; top right, hunting ptarmagin. Bottom left, MacMillan showing to a group of Naskapis pictures of North American Indians; bottom right, a Naskapi fishing through ice 25 9. Frobisher Bay, Baffin Land 27 10. Sir Martin Frobisher, discoverer of Frobisher Bay, Baffin Land 29 11. Jackman's Sound, Frobisher Bay, showing raised beaches 30 12. Top, the Grinnell Ice-cap; bottom, a tongue of the ice-cap 31 13. Echelon crevasse of the Grinnell Ice-cap 32 14. Left, walking over Grinnell Ice-cap; right, rough ice and numerous crevasses ... 33 15. Top, coast of Frobisher Bay. Bottom left, a well-formed cirque; right, portion of Everett Range 35 16. Top, Minturn Bay, Frobisher Bay; bottom, a glacial lake behind Griffin Bay . . 36 17. Contrasting landscapes of Labrador and Baffin Land 37 18. Coastal topography near Newell Sound 39 19. Tidal flats at the mouth of the Jordan River 40 20. Silliman's Fossil Mount. Above, panoramic view; below, areal diagrammatic view . 41 21. Silliman's Fossil Mount, showing first break and nature of rock disintegration . 42 22. Thin section of granite underlying Silliman's Fossil Mount 44 23. Kodlunarn Island, the site of Frobisher's proposed colony 46 24. Excavations on Kodlunarn Island 47 25. Top, hunting for relics in remains of Frobisher's house. Bottom, relics (chips of bricks, flint, coal, tile, and mortar) of Frobisher's house on Kodlunarn Island . 49 26. Top, a pile of lichen-covered rocks, the supposed gold ore. Bottom left, macro- texture of one of the above rocks; right, thin section of the same rock .... 51 27. Top, expedition's winter quarters; bottom, a typical Eskimo house 53 28. Top, ice mound formed by tide waters; bottom, a huge boulder moved five inches during a single season by the work of ice 55 29. o, c, Vertical sections of discoid specimens of Receplaculites and Ischadites respec- tively, showing nature of curvature of peripheral walls, b, Vertical section of a nearly complete specimen of Ischadites iowensis, showing bell-shaped central 5 6 LIST OF ILLUSTRATIONS PAGE cavity, d, Nearly complete specimen of Ischadiles iowensis in which the conical upper portion is preserved, e, Discoid form of Ischadites iowensis 60 30. Diagrammatic representation of component parts of body-wall of Receplaculites (modified after Salter and Billings) 63 31. Receplaculites sp 64 32. ReceptaculitesC!) fieldi Roy 66 33. Receplaculites sp 67 34. Streptelasma spp. I, II, and III 68 35. Favistella sp 69 36. Plasmopora lambei Schuchert 71 37. Plasmopora patlersoni Roy 73 38. Calapoecia canadensis anticostiensis Billings 75 39. Halysites agglomeratiformis Whitfield 78 40. Halysites cf. H. gracilis (Hall) 79 41. Cheirocrinus sp 80 42. Carabocrinus sp 81 43. Atactoporella cf. A. schucherli Ulrich 82 44. Dianulites sp 82 45. Eridolrypa bassleri Roy 83 46. Eridolrypa cf. E. aedalis minor (Ulrich) 84 47. Plectorthis inaequiconvexa Roy 85 48. Platystrophia magnisulcata Roy 86 49. Skenidioides(l) sp 87 50. Hesperorthis interplicata Roy 87 51. Glyptorthis bellarugosa (Conrad) 88 52. Austinella cooperi Roy 89 53. AustinellaC!) subcircularis Roy 90 54. Dalmanella diminutiva Roy 91 55. Dalmanella sillimani Roy 92 56. Dalmanella{1) sp 93 57. Parastrophinella hemiplicata minor Roy 94 58. Rafinesquina pronis Roy 95 59. Rafinesquina declivis subnutans Roy 95 60. Rafinesquina productiformis Roy 96 61. Rafinesquina sp 97 62. Sowerbyella sp 97 63. Slrophomena undulosa Roy 98 64. Strophomena sp. I 99 65. Strophomena sp. II 99 66. Rhyncholrema capax arcticum Roy 100 67. Rhyncholrema anticostiense breve Roy 101 68. Rhyncholrema sp 102 69. Zygospira maynei Roy 102 70. Cyclospira schucherli Roy 104 71. Cyclospira vokesi Roy 105 LIST OF ILLUSTRATIONS 7 PAGE 72. Ctenodonta baffinensis Ulrich 107 73. Ctenodonta cf. C. subnasula Ulrich 107 74. Ctenodonta ulrichi Roy 108 75. Lophospira cf. L. augustina minnesotensis Ulrich and Scofield 110 76. Lophospira sp. I 110 77. Lophospira sp. II Ill 78. Hormotoma rotundivolvis Roy 112 79. Hormotoma spp. I, II, and III 112 80. Eotomaria{1) robinsoni Roy 113 81. Maclurina manitobensis{1) (Whiteaves) 116 82. Maclurina cuneataf!) (Whitfield) 117 83. Maclurina cuneata{t) (Whitfield) 118 84. Maclurites crassus(l) (Ulrich and Scofield) 119 85. Maclurites crassus(1) (Ulrich and Scofield) 120 86. MacluritesC!) sp 121 87. Trochonema cf. T. umbilicalum (Hall) 121 88. Trochonema{1) sp 122 89. HolopeaC!) sp 122 90. Hyolithes crowelli Roy 123 91. Endoceras baffinense Foerste 124 92. Endoceras sp. I 126 93. Endoceras sp. II 127 94. Endoceras sp. Ill 128 95. Endoceras sp. IV 129 96. Ephippiorthoceras sp. I 131 97. Ephippiorthoceras sp. II 132 98. Charactoceras schucherti Foerste 133 99. Actinoceras sp 134 100. Leurorthocerasi?) baffinense Foerste 136 101. Leurorthoceras{t) cf. L. baffinense Foerste 137 102. Kochoceras troedssoni Roy 139 103. Kochoceras sp 140 104. Westenoceras greggi Roy 142 105. Winnipegoceras laticurvatum (Whiteaves) 144 106. N eumatoceras{1) tumidum (Schuchert) 145 107. Cyrtogomphoceras baffinense Foerste 147 108. Cyrtogomphoceras furnishi Roy 148 109. Cyrtogomphoceras sp. I 150 110. Cyrtogomphoceras sp. II 151 111. Diestoceras milleri Roy 153 112. Harpes sp. ind 154 113. Ischyrotoma(1) raymondi Roy 155 114. Remopleurides sp 155 115. Isotelus gigas latior Roy : 156 116. Isotelus cf. /. iowensis (Owen) 156 8 LIST OF ILLUSTRATIONS PAGE 117. Illaenus baffinlandicus Roy 157 118. Illaenus punclatus Roy 158 119. Illaenus cf. /. grqenlandicus Troedsson 158 120. Illaenus sp. ind 158 121. Bumastus sp. ind 159 122. Encrinurus sp. ind 159 123. Calymene platycephala Foerste 160 124. Calymene croneisi Roy 161 125. Calymene macmillani Roy 162 126. Ceraurus cf. C. horridus Troedsson 162 127. Ceraurus sp 162 128. Ceraurinus icarus noduliferus Roy 163 129. a, Pterygometopus callicephalus (Hall), b, "Pterygometopus callicephalus," as shown by Delo 163 130. Diagrams showing forms of different genera belonging to subfamily Pterygometo- pinae. a, Pterygometopus. b, Chasmops. c, Monorakos. d, Eomonorachus. e, Calyptaulax. f, Achatella 164 131. Pterygometopus callicephalus brevis Roy 165 132. Pterygometopus sp. ind. I 166 133. Pterygometopus sp. ind. II 166 134. Calyptaulax sillimani Roy 167 135. Eomonorachus deloi Roy 168 136. Leperditia cf. L. ulrichi Troedsson 169 137. Isochilina convexa Roy 170 138. Aparchites(l) sp . . , 171 139. Primitia cincinnatiensis (Miller) 172 140. Halliella jaynesi Roy 172 141. Eurychilina bassleri Roy 173 142. Eurychilina sp 174 143. Krausella rawsoni Roy 175 144. Krausella cf. K. inaequalis Ulrich 175 145. Krausella sp 176 146. Bythocypris aff. B. cylindrica (Hall) 176 PREFACE The data and material upon which this paper is based were collected by me during the seasons of 1927 and 1928, while I was serving as geologist of the Rawson-MacMillan Expedition of Field Museum to Labrador and Baffin Land. The trip was a most profitable and enjoyable one and I wish to take the oppor- tunity here to express my deep gratitude to the late Frederick H. Rawson and to Mr. Stanley Field, the sponsors of the expedition. Mr. Field, furthermore, took a deep interest in the progress and accomplishment of the expedition from the very outset. His frequent radio messages of encouragement and his inquiries as to the general well-being of the members of the expedition were a stimulating influence in our activities and doubtless exerted a strengthening effect on our morale. I also take the opportunity to acknowledge here my indebtedness to Lieu- tenant Commander Donald B. MacMillan, U.S.N. R., who was in command of the expedition, and to Captain J. T. Crowell of Gloucester, Massachusetts, who was second in command and in charge of the trip to Frobisher Bay, Baffin Land. Born to the sea and ever watchful of its thousand hazards, they sailed the ship through the uncharted' seas without a major mishap and conducted the activities of the expedition with commendable efficiency. I shall long and grate- fully remember the consideration shown me by Commander MacMillan and Captain Crowell and value the experience I gained from my close and sustained contact with them. In this connection I cannot forbear acknowledging my sincere appreciation to each and every member of the expedition for his sportsmanship and cheerful co-operation in all matters. I wish to thank particularly Messrs. Ralph Robinson and John Jaynes, who accompanied me to Silliman's Fossil Mount, Frobisher Bay, Baffin Land, and helped me to make the collection comprehensive as well as representative. My chief task in the expedition was to collect fossils from Silliman's Fossil Mount and to make observations on the geology of the coasts that we were to visit. These objectives were attained, but I believe that a still greater measure of success might have been achieved if arrangements could have been made whereby it would have been possible to make more frequent landings and spend longer time in localities which were found to be particularly interesting from a geologic point of view. It must be clear, however, that, owing to the varied interests of the expedition, it was impracticable either to land oftener or to make longer stays in localities that were of interest to the geological personnel only. There are advantages as well as disadvantages of an expedition repre- senting different branches of natural history, and it remains a moot question whether or not the composite results obtained in such an expedition are com- mensurate with the losses sustained by individual branches. The point is a very important one for a museum, which, for its success, rightfully expects 10 PREFACE every member of its scientific staff not merely to collect specimens for exhibits but also to secure adequate data of his observations for research, and for new fields of endeavor to be entered upon in the future. The main subject matter of this memoir consists of the description and the determination of the stratigraphic range of the fossils collected at Silliman's Fossil Mount. I have, however, included at the beginning a chapter entitled, "Narrative of the Expedition with Notes on the Coastal Geology of Labrador and Baffin Land." This has been introduced to maintain continuity of observa- tions, to give the reader a bird's-eye view of the expedition as a whole, and to bring out such incidents as have been thought to contain elements of general interest. Personally I believe that nothing is lost, and much is gained if inci- dents and episodes of human interest of an expedition are recorded along with the report of its scientific results, particularly if the expedition has been con- ducted in far-off and little known places. I am fully aware of the fact that this paper should have been prepared and published earlier than this but I feel that I need not offer an apology for the delay. Until a little more than a year ago, when additional members were added to the staff of the Department of Geology, I had had no opportunity to devote the time needed for its completion. With the appointment of new mem- bers, I was relieved of much of the routine work and was thus, for the first time since I returned from the expedition, able to give my undivided attention to the preparation of the paper. My work was further facilitated by the splendid support I received from the Director of the Museum, Major Clifford C. Gregg, and from the Chief Curator of Geology, Mr. Henry W. Nichols. I wish to extend to both my sincere appreciation and heartfelt thanks. To Major Gregg I also owe a debt of gratitude for granting me leave to visit other museums and universities for the purpose of furthering my investigations in this connection, and for generously providing me with all needed equipment. During my visits to other institutions I have called upon a number of geologists who, as authorities in their fields, have rendered me invaluable aid by checking over my identifications, by giving me access to their study col- lections for examination, and by discussing some of the controversial problems that have arisen from time to time. I wish especially to mention that every- where I went I was met with unfailing courtesy and was given every assistance needed to make my visits profitable as well as enjoyable. My profound appre- ciation and gratitude are due to Dr. R. S. Bassler, of the United States National Museum, for his help in the identification of some of the difficult forms described in the sections of Bryozoa and Ostracoda; to Dr. Charles Schuchert, of Yale University, for giving me the benefits of his views on the fauna as a whole, and of his extensive knowledge of arctic stratigraphy; to Dr. E. 0. Ulrich, of the United States National Museum, for checking over the identifications of Pelecy- poda and Gastropoda and for discussing at length with me some of the more com- plex problems of correlations; to Dr. Josiah Bridge, also of the Geological Survey, for generously allowing me to share his office and for assisting me to find allied PREFACE 11 species of gastropods for comparative studies; to Dr. G. Arthur Cooper, of the United States National Museum, for his valuable criticisms and suggestions for changes in the section on Brachiopoda and for making available to me the entire collection previously made at Silliman's Fossil Mount; to Dr. Percy E. Raymond, of Harvard University, for kindly going over my manuscript in the section on Trilobita and for directing me to references I had overlooked; to Dr. A. K. Miller, of the University of Iowa, for assisting me in the identifications of cephalopods, for reading the description of nearly every species, and for the courtesies and facilities he extended to me during my stay at Iowa City; and finally, to Dr. Carey G. Croneis, of the University of Chicago, for the patient and laborious work of reading the entire manuscript and for making numerous suggestions and alterations. This paper could not have appeared in its present form without the personal interest taken by Dr. Croneis. For this, and for his constant encouragement and sympathetic helpfulness, I offer him once again my most sincere and hearty thanks. I am also obligated to Dr. G. Marshall Kay, of Columbia University, for explaining to me some of the questions relating to the "Ordovician Stewartville- Dubuque Problems," and to Dr. H. E. Vokes, of the American Museum of Natural History, for the loan of specimens previously collected by Mr. R. W. Porter at Silliman's Fossil Mount. My colleagues, Messrs. Bryan Patterson, Paul McGrew, and Henry Herpers, have helped me in many ways. Mr. Patterson has read a greater part of the manuscript and has made valuable suggestions. Mr. McGrew and Mr. Herpers have assisted in the preparation of photographs of microfossils and of certain specimens requiring the use of special techniques. It is my pleasant duty to extend to them my very sincere appreciation. The manuscript was typed, in part, by my assistant, Mr. Henry Horbeck, and completed by Mrs. Corine Mintrop. I wish to thank them for their labors. As in all Field Museum publications, the responsibility of editing the manuscript and seeing it through the press has fallen upon the Staff Editor, Miss Lillian A. Ross, to whom my grateful thanks are due. The task of editing the memoir has been particularly difficult and Miss Ross is to be commended for her painstaking efforts to give the volume an attractive dress. The pictorial photographs were taken by various members of the expedition and the greater part of the photographs of fossils by the Staff Photographer, Mr. C. H. Carpenter. The drawings and retouchings were the work of Staff Illustrators, Mr. Carl F. Gronemann and Mr. John J. Janecek. The collotype reproduction of all figures was by the Staff Collotyper, Mr. A. A. Miller. In conclusion, I wish to add that although I have received invaluable aid by various authorities and have guarded to the best of my ability against errors, there must still be some which have escaped my attention. For any errors that may exist I alone am responsible. Sharat Kumar Roy NARRATIVE OF THE EXPEDITION WITH NOTES ON COASTAL GEOLOGY OF LABRADOR AND BAFFIN LAND Fig. 1. Map showing route of Rawson-MacMillan Expedition of Field Museum to Labrador and Baffin Land. 14 NARRATIVE OF THE EXPEDITION INTRODUCTION The expedition was organized to spend two summers and a winter (June, 1927-September, 1928) cruising the coastal waters of Labrador and Frobisher Bay, Baffin Land, with headquarters at Anatalak Bay, about twenty miles northwest of Nain, Labrador. The object was to make extended observations and collections relating to anthropology, botany, geology, and zoology, for Field Museum. The personnel was composed of fifteen men: Lieutenant Commander Donald B. MacMillan, in charge; Captain J. T. Crowell, in charge of the trip to Frobisher Bay; Ralph Robinson, mate; Frank Henderson, second mate; John Jaynes, engineer; E. K. Langford, surgeon; Clifford Hymoe, radio operator; Martin Vorse, cook; Abie Broomfield, Eskimo interpreter; Charles Sewall, botanist; Novio Bertrand and Arthur G. Rueckert, taxidermists; Alfred C. Weed, ichthyologist; W. Duncan Strong, anthropologist; and Sharat K. Roy, geologist. The last four members were from the staff of Field Museum. The means of transportation consisted of three boats and a snowmobile. Of the three boats two were schooners, the Bowdoin and the Radio, and one a 35-foot cabin cruiser, the Seeko. The snowmobile was used for travel over frozen waterways during the winter. To those contemplating an expedition to Labrador or farther north, it may be helpful to point out that various villages on the coast of Labrador, as far as Nain, may be reached for about three months, usually from July to Sep- tember, by means of coastal steamers. The movements of the steamers, how- ever, are irregular and cannot always be depended upon. There are no boats available at any time that will carry passengers to Baffin Land. An expedition intending to explore that region must provide its own means of transportation. FORTEAU BAY: RAISED BEACHES AND GLACIAL STRIAE We sailed from Wiscasset, Maine, on June 25, 1927, and reached Sydney, Nova Scotia, three days later. Here we took on 28,000 feet of lumber for our winter station and left for Battle Harbor, Labrador, on July 6; but, before we could reach our destination, heavy fog forced us to take shelter in Forteau Bay on the southeastern shore of Quebec in the Gulf of St. Lawrence. The bay is bordered by a magnificent raised beach of the wave-cut terrace type. Raised beaches of this kind, which, so far as known, are all of postglacial age, were later found at almost every bay and inlet along the coast of Labrador. They occur at various heights above the present sea-level and furnish a striking proof of the recent emergence of the land. In general, the elevated shore-lines in the St. Lawrence Valley are higher than those observed northward along the Labra- dor coast. This observation seems to indicate that the Labrador ice-sheet was relatively thicker to the south; and hence, that region, because of the greater 15 16 ORDOVICIAN FOSSILS OF BAFFIN LAND weight of ice, was more depressed. At Forteau Bay, erratic boulders of granite and pegmatite of glacial origin were found in great abundance on the terraces, particularly on those at higher levels. Glacial markings, indicating southeastern movement of the ice, were observed on bare ledges above the terraces. ICEBERGS On the following day (July 7), with the first sign of clear weather, we got under way and soon fell into the Strait of Belle Isle. It had been an unusual summer. There was little or no floe ice to be seen, but the ocean seemed packed with hundreds of icebergs (Fig. 3) of every size and description — more than had been seen in any one season within the memories of the oldest inhabitants. The icebergs were derived almost entirely from the Greenland ice-cap, chiefly through the calving of three large glaciers, Jacobshavn, Torsukatak, and Gara- jag (pronounced Karaiak), which descend into the sea on the west coast at a latitude approximately 70° N., between Christianshaab and Umanak. Once free, the icebergs find their way to the open sea and drift southward with the Labrador Current along the coasts of Baffin Land and Labrador, then along the east coast of Newfoundland to the Grand Banks and the routes of the trans- atlantic liners. The average rate of drift, if not slowed down by floe ice, is about ten miles per day. The journey south, however, is not an easy one, for large numbers of the icebergs meet destruction on the way, either by becoming grounded or by being stranded along the coast. Those that survive the trip and become an actual menace to transatlantic navigation are comparatively few. BATTLE HARBOR AND ASSIZES BAY: LITHOLOGY AND GLACIAL STRIAE At dawn on July 8, Battle Harbor, Labrador, was sighted. We steamed past it and anchored in Assizes Bay. Now, for the first time, we encountered the dreaded mosquitoes and black flies. It is well to emphasize here that they are far more formidable a menace than is usually believed. Although we were equipped with the best-known protections against these horrible pests, none proved equal to the situation. Of the two evils of the North — mosquitoes and flies in summer and bitter cold wind in winter — the latter is by far the more bearable. The rocks around Assizes Bay are predominantly metamorphics — con- torted gneisses and schists, cut extensively by quartz, granite and diabase dikes. Slightly altered granites and diorites and a basic rock composed chiefly of horn- blende, probably hornblendite, are also present in large masses. Glacial striae having a general southeast direction are common on outcrops at the hilltops. AILLIK BAY: LITHOLOGY, GLACIAL STRIAE, AND LUNOID MARKINGS We continued our journey northward and, after calling on the way at Spotted Island, Isle of Ponds, Gannet Island, Indian Harbor, and Aillik Bay, Fig. 2. Sketch map of Labrador coast showing approximate positions of villages, some of which were visited by the members of the expedition. 17 18 ORDOVICIAN FOSSILS OF BAFFIN LAND reached Hopedale five days later. From a geologic point of view, the region around Aillik Bay is of more than usual interest. The bay, which trends in a northeast-southwest direction, is some five miles long and about a mile wide, and has excellent coves for safe anchorage. It is surrounded by high ridges com- posed of rocks very similar to those observed in Assizes Harbor. At the base of these ridges, not far from the beach, lies a second ridge — a belt of quartzite dipping toward the mainland. The belt is not continuous. It is narrow — about one hundred feet thick — and terminates at the mouth of the bay, where both of its ends are cut off by massive gneissoid granites. The quartzite is strikingly banded, shows cross-bedding in places, and is traversed by numerous dikes of both acid and basic rocks. No fossils were found in the quartzite, but appar- ently the formation is younger than the crystalline rocks which it overlies. Metamorphosed conglomerates and quartzites are also found at Pomiadluk Point, about sixteen miles southeast of this area, but it is not known whether or not these rocks are contemporaneous with the Aillik Bay quartzite. We had no opportunity to go ashore at Pomiadluk Point and consequently no studies bearing on the relationships between the two quartzites could be made. The direction of the ice-movement in the vicinity of Aillik Bay, as indi- cated by the striations, appears to have been northeast. Associated with the striations, groups of well-formed lunoid markings were observed. These cres- cent-shaped markings are thought to have been the result of tension set up in the bed-rock at the gouging corner of an angular boulder caught in the advanc- ing ice. They have been seen and discussed by practically every geologist who has visited the Labrador coast. Further discussion of their origin seems unneces- sary, particularly since no experimental data are at hand. LABRADOR ESKIMOS AT HOPEDALE Before we were halfway into the harbor of Hopedale, the Eskimos came paddling out in kayaks (Fig. 4) and swarmed up our boat's ladder like a group of excited children. For friendly spirit, good faith, and sportsmanship it is difficult to match the Eskimo's character. Unfortunately, his future does not seem promising. His contact with civilization appears to have done him more harm than good. Venereal and pulmonary diseases are widespread and have visibly affected his health and spirit. This is especially true of the Labrador Eskimo. ROCHES MOUTONNEES AND ROCK BASIN LAKES Hopedale, the seat of a Moravian mission established in 1782, is situated at the head of a wide bay. Terraced, rounded hills, having a general roche moutonnee form (Fig. 4), with small lakes (Fig. 5) located on or among them, constitute the major features of the landscape. The bed-rock is predominantly gneiss, but more severely contorted, sheared, faulted, and injected by dikes than that heretofore observed. At various places on the surfaces of roches moutonnees, glacial striae indicating a northeasterly movement of the ice, and lunoid mark- ings in groups, are of common occurrence. i m m Fig. 3. Icebergs on the coastal waters of Labrador. They were derived almost entirely from the Greenland ice-cap. 19 20 ORDOVICIAN FOSSILS OF BAFFIN LAND NAIN Piloted by Eskimos through narrow, circuitous inlets among a maze of islands, locally known as the "inside run," we headed for Nain and dropped anchor there the following noon. Perched above a valley rimmed by high Fig. 4. Left, rockes moutonnees at Hopedale, Labrador; right, Eskimos paddling out in kayaks. hills, Nain commands a picturesque view. It is the oldest Moravian mission station in Labrador, dating back to 1771. NAIN ANORTHOSITE In approaching the vicinity of Nain, a striking change from the prevailing gneiss to anorthosite becomes apparent in the character of the bed-rocks. The abrupt change begins at Paul Island, in Ford Harbor, a few miles directly east of Nain, and continues uninterruptedly northward, at least to Port Manvers. Like the Hopedale gneiss, the Nain anorthosite is cut rather extensively by dikes of aplite, granite, and pegmatite. In places the anorthosite contains large masses of pure labradorite of gem quality. As a rule, the labradorite is more coarse-grained than the country-rock, but there are no indications which suggest that the two were not formed contemporaneously. In reflected light, the mineral shows a brilliant display of color, and because of this it has long attracted the attention of the natives. Its occurrence, however, was not known to the outside world until 1770, when samples of it were collected by a Moravian Brother from Paul Island and shipped abroad for possible use in the gem indus- COASTAL GEOLOGY 21 try. In recent times, it was quarried on a large scale by Mr. R. G. Taber on Napotlulagatsuk Island, between Paul Island and the mainland, about twelve miles east of Nain. The enterprise, however, was not successful. The failure was attributed to the difficulty of getting out large slabs intact. Due to the ■ I ,^' -*?r ' ~**<*^ji&J* Fig. 5. Rock-basin lakes in the vicinity of Hopedale, Labrador. complicated cleavage system that the mineral possesses, much of the material was shattered during the process of quarrying it. SCULPIN ISLAND: DRIFT FOSSILS Soon after our arrival at Nain, the work of the expedition fell into routine. At Anatalak Bay, twenty miles northwest of Nain, a site on which to build our winter quarters (Fig. 27) was selected. It was an ideal location for our purpose, since we did not have to contend with the problems of obtaining either water or firewood. A nearby mountain brook and surrounding woodlands of spruce and balsam fir supplied us plentifully with both (Fig. 17). While the house was being built, we took turns making a number of excursions to the neighboring islands. Of these, the trip to Sculpin or Kanaiotok Island, about twenty-one miles northeast of Nain, was perhaps the most productive. It is commonly believed that this island was settled by Norsemen some nine hundred years ago and that the ruins found there might be Norse. A survey of the ruins and examinations of the artifacts, however, led our anthropologist, Dr. William Duncan Strong, to conclude that the site represents an Eskimo spring or autumn camp of the Thule culture rather than an early attempt at colonization by the Vikings. On this island twenty-two drift fossils representing four genera and 22 ORDOVICIAN FOSSILS OF BAFFIN LAND six species (Hormotoma labradorensis Roy, Hormotoma minuta Roy, Turritoma cf. T. ada (Billings), Helicotoma rawsoni Roy, Bathyurus sculpinensis Roy, and Bathyurus(t) sp. were found (Fig. 6). They clearly compose a typical Upper ■A Fig. 6. Upper Canadian (Beekmantown) drift fossils from Sculpin Island, near Nain, Labrador, a, b, Hormotoma labradorensis Roy; c, Hormotoma minuta Roy; d, Turritoma cf. T. ada (Billings); e, f, g, Helicotoma rawsoni Roy; h, i, Bathyurus sculpinensis Roy; j, Bathyurus{1) sp. Canadian fauna of the American Atlantic phase, hitherto not found in the American arctic or eastern subarctic regions, and indicate a much wider distri- bution of the northern Canadian faunas than was heretofore believed. (For a more complete discussion of the subject, see Roy, 1932.) COASTAL GEOLOGY GLACIAL STRIAE AND BOULDER REEFS 23 Glacial striae, indicating a northeasterly movement of the ice, were observed in some of the outer islands north of Ford Harbor, but none of the lunoid mark- ings, so well developed along the southern coast, was seen. Judging from the general direction of the glacial striae — southeast, east, and northeast — thus far observed at Forteau Bay, Assizes Harbor, Aillik Bay, Hopedale, and in the neighborhood of Nain, it is apparent that the ice moved outward from a center Fig. 7. Boulder reef, near Nain, Labrador. Most of the boulders are of glacial origin. Photograph by E. P. Wheeler II. of accumulation. An unusual feature of the glacial geology of the southern coast of Labrador is the scarcity, commonly the total absence, of drift deposits. With the exception of erratics on raised beach terraces and small isolated deposits of till, no other deposit of glacial origin was observed. A type of deposit which consists predominantly of glacial boulders but which cannot be termed a glacial deposit was observed along shores of certain bays and islands in the vicinity of Nain. This type of boulder formation is commonly called a "boulder reef" or "boulder barricade" (Fig. 7) and is found at distances ranging from a few feet to 150 feet from the shore, where the gradient is moderately steep, to a short distance below low tide. The way in which such deposits are formed is not clearly understood. According to Daly they are the result of the combined work of tide, undertow, surf, and landfast ice, during and after the postglacial uplift of the land. Daly's interpretation, which appears to be a very plausible 24 ORDOVICIAN FOSSILS OF BAFFIN LAND one, is as follows (Daly, 1902, pp. 260-261) : "As the land emerged, the boulders (from the wave-swept zone immediately above) were dragged down in the under- tow and lodged just below the level where surf could move them. The relative absence of boulders between the shore and the barricade is also explained in part by the action of coast ice, which floats off such boulders when the ice-foot breaks up. If the boulders happened to be dropped again just at the limit where, on account of the depth, the surf is no longer effective in moving boulders resting on the bottom, the erratics would further build up the wall constructed by the undertow. Very close to that limit of effective wave-wash, the winter ice, because of the depth at which the boulders lie (submerged at high tide), would not be able to buoy up the heavy masses and float them away." NASKAPI INDIANS Apparently, news of our arrival in Anatalak Bay reached the Naskapi Indians. One evening, three dark specks appeared across the bay. Soon pad- dles could be seen flashing as the copper-skinned crew drew closer. Rarely, in North America today, can one get the thrill that comes with the first sight of a Naskapi, for the Naskapi are truly wild Indians, living by the hunt as their ancestors did before them. From Northwest River to Ungava Bay, and extending inland for more than a hundred miles, is an unexplored area of 300,000 square miles entirely unoccupied save by one hundred Indians. No reservations confine their movements and the vast interior is their hunting ground. The lot of a Naskapi, however, is not a happy one. Hard as his life is in summer, beset by the dreaded insects as he portages his canoe over long mus- kegs from one waterway to the next, his winter life is even more precarious. The lakes, ponds, and rivers are many feet thick with ice, and the animals, none too abundant in summer, seem now to have utterly vanished. On snowshoes, the hunter wanders (Fig. 8) day after day on the lookout for such caribou as the Caribou God may send in answer to his prayers. If night finds him on the Barrens, he may burrow in the ground, build a huge fire and alternately sleep and feed the fire; or else he may heap up a pile of snow, let it freeze and hollow it out with a snowshoe to form a cave, which, sealed tightly, will let him pass the bitter night in comparative warmth. When the caribou are not to be found the Indians starve; often the men drop in their tracks while roaming the desolate and endless Barrens looking for game where there is no game. But the menace of lonely land and an uncertain food supply does not depress the Naskapi, who have always faced such odds. "Sufficient unto the day are the evils thereof," is a sentiment wholly in keeping with Indian psychology. When there is meat, there is continuous feasting; when there is no meat, there is no complaining. TO FROBISHER BAY, CAPE MUGFORD, HUDSON STRAIT, AND RESOLUTION ISLAND Our trip to Frobisher Bay, Baffin Land, was considerably delayed because of lack of information regarding ice conditions in Davis Strait. Finally, on -•£- ." Fig. 8. Top left, a Naskapi Indian in traveling gear; top right, hunting ptarmagin. Bottom left, MacMillan showing to a group of Naskapis pictures of North American Indians; bottom right, a Naskapi fishing through ice. 25 26 ORDOVICIAN FOSSILS OF BAFFIN LAND August 7, we received favorable news and got under way the following day before sunrise. Steaming through the calm waters of the "inside run" to Port Manvers, we swung north to the open sea. The shadow of the iron-bound coast with perfect images of the sentinel-like cliffs of the Kiglapait Range fell far over us out at sea. This range is some twenty-five miles long, its axis running approximately parallel to the coast-line. Almost immediately after we had passed the Kiglapait, Cape Mugford loomed up in stately grandeur. Three thousand feet of metamorphosed sediments and intercalated diabase sills rose straight out of the sea. The metamorphosed rocks, consisting chiefly of slates, quartzites, and altered agglomerates, lie unconformably over some five hundred feet of irregularly eroded gneisses and schists. It is much to be regretted that we could not spend a longer time here, for besides being one of the grandest bits of scenery in North America, this region offers a splendid opportunity for geo- logical exploration and research. Dusk fell as we rounded the cape. During the night, we passed by Hebron, Saeglek Bay, Ramah, and Nachvak Bay and so saw little of this section. Early in the morning, the bleak, forbidding countenance of the Torngat, aptly called the "Evil Spirits" by the Eskimos, appeared in the distance, but our course kept us too far offshore to get a clear view of this ragged chain of mountains. It is believed that the continental ice-cap did not cover the Torngat and that its Alpine character has been preserved from pre-glacial times. As we passed Cape Chidley, the northernmost tip of Labrador, and entered Hudson Strait, the air became colder and the sea rougher. The tide was excep- tionally strong, and we could make but little headway. At times, we were actually driven backwards. During the night, a strong southeasterly wind shrieked viciously, tearing the tops of great waves into a haze of driving spray. A succession of seas broke full on the stern and tons of icy water poured in a roaring torrent, filling the deck high above the hatches. The little ship stag- gered and quivered but shook herself clear. At daybreak, a heavy fog came down with incredible rapidity, blotting out our view of Resolution Island 1 — our only land mark. Squalls of sleet and sudden snow flurries scourged down at intervals. Huge waves thundered against uncharted reefs, sending up great clouds of spray, and a seemingly endless stream of icebergs loomed up ghost- like through the mist, too close to the ship for comfort. Tide and cross- currents drove us off our course, and for a time we were completely lost in the maelstrom. So small was our ship and so great were the seas that it took all the strength of the helmsman to keep the wheel from spinning. Realizing our predicament, we veered east to seaward and hove to, rising and falling on the unbroken swell, until the fog lifted. There was still some daylight left when we entered Frobisher Bay, Baffin Land, and anchored in Jackman's Sound on the northwest coast of the bay. 'Since then Resolution "Island," situated at the entrance of Hudson Strait (Lat. 61° 31' N.; Long. 65° W.) with an area of about 1,600 square miles, has been partially explored and found to be not one island but a group of islands. c e « cS PQ I) a> .c o C5 o 27 28 ORDOVICIAN FOSSILS OF BAFFIN LAND FROBISHER BAY: TIDES Frobisher Bay (Fig. 9), a westerly arm of Davis Strait, is located at the southern extremity of Baffin Land, between Hudson Strait and Cumberland Sound. Its entrance, which is about 55 miles wide, is bounded on the north by Lok's Land and on the south by Resolution Island. The bay extends in a gen- eral northwesterly direction for about one hundred and fifty miles and contains numerous islands, reefs, ledges, and shoals. The upper part of the bay is divided into two arms: Ward's Inlet to the northeast, and the headwaters of the bay itself to the northwest. The intervening land between these two arms is known as Becher Peninsula. Northwest of the peninsula, the bay receives two good- sized rivers, the Jordan and the Sylvia Grinnell, the former emptying directly into the head of the bay and the latter twelve miles west of it. In their physical characteristics, one is a counterpart of the other, each having similar widths, gradients, and valley walls. In addition to these two rivers, there are several smaller ones but none of them seems to have played an important role in develop- ing the configuration of the coast line. West of the valley of the Jordan, on the side of the Meta Incognita or the Kingaite, as the Eskimos call it, stands Silli- man's Fossil Mount, a table-topped ridge of limestone and the only limestone deposit in the entire region surrounding the bay (see p. 42) to be seen in situ. In general, the topography on both sides of the bay is high and rugged, and both shores are indented with numerous fiords and long winding inlets. Of the two, however, the coast of Meta Incognita (west coast) is considerably higher, bolder, and more severely dissected. It harbors on its southwest side a sizeable ice- cap (see p. 34) and small mountain glacierets. The tides in the bay are exceptionally high, varying from twenty-four to forty-eight feet. This tremendous rise and fall is a serious menace to navigation, particularly because the bay has never been surveyed hydrographically. Ordi- narily, the safest time to travel in the bay is at periods of low tide. During times of high tide, numerous low islands become submerged, making passage extremely hazardous. Low tide is also the safest time to look for anchorage. Once, as a result of anchoring at high tide, we came close to experiencing what might have been the end of the expedition, for when the tide ebbed, the water dropped six fathoms, leaving the boat high and dry with her masts canted at an angle of thirty degrees. Tides and rocky shoals, however, are not the only obstacles; the region is notoriously stormy and is obscured by fog much of the time. VOYAGES OF SIR MARTIN FROBISHER Frobisher Bay, long believed to be a strait connecting the Atlantic and the Pacific oceans, was discovered in 1576 and named in honor of its discoverer, Sir Martin Frobisher (Fig. 10), an English navigator and explorer. He is credited with being the first to venture the American Arctic, having pressed westward before Hudson and northward before Davis. Between the years 1576 and 1578, he commanded three voyages of discovery to the Arctic under the patronage of Queen Elizabeth. On his first voyage, in search of the Northwest Passage to China, one of his sailors picked up a black rock resembling coal, near what is COASTAL GEOLOGY 29 now known as Hall's Island, at the north end of the entrance to Frobisher Bay. To test its combustible qualities, the wife of the sailor who brought it home threw it into fire, where, instead of burning like coal, it "glistened with a bright marquesset of golde." The story of the incident soon spread and the stone was turned over to an alchemist, Baptista Angello, for identification. He declared that the sample contained gold and produced a few grains purporting to have Fig. 10. Sir Martin Frobisher, discoverer of Frobisher Bay, Baffin Land. come from it. On the strength of this statement, Frobisher raised money enough to lead two more expeditions and brought back to England a total of 2,100 tons of black rock — 800 tons on the second voyage and 1,300 tons on the third. The "ore" (see p. 48), however, proved worthless and Frobisher was at once besieged by angry investors demanding an explanation. He had none to give, but escaped being heavily compromised through the intervention of the Queen, who not only absolved him of all charges but further redeemed his name from any obloquy by giving him the command of a ship of the Royal Navy. Later, Frobisher commanded the Triumph against the Armada and defended his ship with astound- 30 ORDOVICIAN FOSSILS OF BAFFIN LAND ing daring against a vastly superior strength. Because of this he was knighted by the Lord High Admiral. He died in 1594 from a wound received in action against the Spaniards off Brest. THE DISCOVERIES OF CHARLES F. HALL Frobisher's geographical achievements were practically lost to the world until the year 1861. That year an American naval officer, Captain Charles F. Hall, who was seeking possible survivors of Sir John Franklin's ill-fated expe- Fig. 11. Jackman's Sound, Frobisher Bay, showing raised beaches. M. J. Buerger. Photograph by dition, visited Frobisher Bay, then known as Frobisher Strait. He reached its headwaters, and found that the "strait" was but an enclosed arm of the sea and not the famous Northwest Passage to China, as Frobisher had supposed. On his return journey from the head of the bay, Hall accidentally stumbled upon evidences 1 of Frobisher's third voyage, at Kodlunarn Island, in Countess of Warwick Sound. At that time he was not familiar with Frobisher's voyages but he made a thorough search of the ruins (see p. 48), which he later found were linked inseparably with the activities of Frobisher. The place names in and around Frobisher Bay were given entirely by Hall and Frobisher. Hall also made an outline geographical map of the bay — the only one ever made of the region. This map, which accompanies his book 1 On his third voyage, Frobisher brought with him one hundred miners and assayers who were to estab- lish a colony on Kodlunarn Island and build a fort to guard the "gold deposits" against the natives. ' The attempt failed but the foundation of a small house was laid to see what effect the climate would have on it by the ensu- ing year. Apparently, Frobisher contemplated a fourth voyage. Fig. 12. Top, the Grinnell Ice-cap; bottom, a tongue of the ice-cap. Bottom photo- graph by M. J. Buerger. 31 32 ORDOVICIAN FOSSILS OF BAFFIN LAND "Arctic Researches and Life among the Esquimaux," is most helpful as a gen- eral guide, but it contains many inaccuracies due to the fact that it was pre- pared from sights, the greater number of which were taken from across the bay and that, too, in the winter, when the snow covered both ice and land. Fig. 13. Echelon crevasse of the Grinnell Ice-cap. Photograph by M. J. Buerger. JACKMAN'S SOUND, GRINNELL ICE-CAP, AND EVERETT RANGE Jackman's Sound, our first anchorage in Frobisher Bay, is in Lat. 62° 22' N., Long. 66° 10' W. It is wider and longer than is shown on Hall's map, and shoal water extends nearly a mile offshore. The shoaling is very abrupt, and there is a real danger of running aground. The head of the sound or bay is bounded by a series of wave-cut raised beaches of varying heights (Fig. 11). The highest one is about 180 feet 1 above the level of high tide, indicating that Baffin Land has risen out of the sea to at 1 Calculated by Dr. M. J. Buerger in a later (1937) expedition to Frobisher Bay (Buerger, 1938). COASTAL GEOLOGY 33 least that height since Pleistocene time. Back of the beaches is a wide valley that extends in an east-west direction for several miles and forms a transverse pass, dividing the Grinnell Ice-cap into two separate units. The valley is filled with fluvio-glacial deposits and is probably an elevated outwash plain, now trenched almost down to sea-level by a good-sized stream which, following a slightly sinuous course, empties into the bay, cutting through the beaches at the south end. Fig. 14. Left, walking over Grinnell Ice-cap; right, rough ice and numerous crevasses. During the two days we were fogbound in this place we made several attempts to study the ice-cap, but with little success. Ascending the hills to the southeast we reached the ice-cap (Fig. 12), but the visibility was so poor and the ice was so slippery and so full of crevasses (Figs. 13, 14) that walking without the aid of crampons proved impracticable. On the morning of August 12, without waiting for the weather to clear, we raised anchor and sailed northwestward toward the head of the bay, keeping as close to the shore as safety would permit. The coastal range presented one un- broken line of jagged cliffs (Fig. 15), averaging at least two thousand feet in 34 ORDOVICIAN FOSSILS OF BAFFIN LAND altitude. Farther up the bay, at remarkably regular intervals, tongues of the ice-cap forced their way to the water's edge (Fig. 12). Several of these were seen, but none was very high or very thick. The largest one, having a frontage of about four hundred feet and a height of about two hundred feet, was found in Watt's Bay, just past President's Seat in the Everett Range. This bold chain of mountains, with its mantle of perpetual ice, numerous cirques (Fig. 15), tarns, aretes, and serrated peaks towering high above the surrounding hills, lends to the coastal topography an air of rugged magnificence that cannot be surpassed in all of eastern North America. The ruggedness is obviously the result of destructive work by the numerous ice-tongues and of quarrying and frost- weathering by the many snowdrifts and glacierets harbored by the fretted upland. GRIFFIN BAY: INLAND TOPOGRAPHY We tried to reach the ice tongue in Watt's Bay but the sea was still very heavy and we could not effect a landing. Late in the afternoon we entered Minturn Bay (Fig. 16) but could find no anchorage with a hundred-fathom chain within a quarter mile from shore. At dusk we entered Griffin Bay. This is also a deep bay with no good anchorages. Hunting about for some time, we finally anchored at the mouth of a small stream on the south side near the head of the bay and moored to cliffs with quarter lines. Behind our anchorage, separated only by a narrow neck of land, we found a large glacial lake (Fig. 16). It is roughly L-shaped and forms the terminus of a glacial trough which extends inland for many miles to the southwest. The water level of the lake is a foot or less above the high tide, so that at high tide, when accompanied by a strong northwest wind, the sea water enters it and at three-quarters tide the lake water rushes out over the neck of the land like a miniature waterfall. Taking advantage of fair weather, we worked our way inland over the glacial trough for a distance of four miles or more, and for the first time got a good view of the interior (Fig. 17). It is difficult to conceive of a more bleak and desolate country. Low, rounded, snow-capped hills rose one beyond the other until lost in the mist of tundra lands. Not a twig, not a shrub relieved the monot- ony of the incredibly barren landscape. As to the ice-cap, we had already passed it. From the summit of a high hill facing southeast, we could see a portion of it lying in a southeast-northwest direction, some four miles away. Its advance on the coast appeared checked by the bold walls except at a few flanks where it was finding its way to the sea. We had, however, no way of judging its extension into the interior, for the bordering line of extension was completely obscured by clouds of vapor rising out of the surface of the ice. GRINNELL ICE-CAP Since our visit to Frobisher Bay, three other parties have explored this ice- cap, each gathering additional data. Piecing these together, it has been possible to construct a fairly complete picture of the ice-cap (Roy, 1937 and 1938). To summarize: The ice-cap occupies the summit of the highland between Hudson Strait and Frobisher Bay. It has characteristics intermediate between those Fig. 15. Top, coast of Frobisher Bay. Bottom left, a well-formed cirque; right, portion of Everett Range. 35 Fig. 16. Top, Minturn Bay, Frobisher Bay; bottom, a glacial lake behind Griffin Bay. 36 Fig. 17. Contrasting landscapes of Labrador (top) and Baffin Land (bottom). 37 38 ORDOVICIAN FOSSILS OF BAFFIN LAND of mountain and continental glaciers, and may well have evolved from earlier mountain glaciers. It is not continuous but is separated by a transverse valley (NE.-SW.) at Jackman's Sound (Lat. 62° 22' N., Long. 66° 10' W.) into two distinct units — the southeastern and the northwestern ice-caps. The south- eastern one is situated at a lower altitude, is smaller, and sends no ice-tongues down to the sea. The absence of ice-tongues may be traced to the wasting of neve and ice by the direct rays of the sun, to which the ice-cap is largely exposed. The coastal topography bordering this ice-cap has retained the rounded forms left by the earlier continental ice-sheet. The northwestern ice-cap is the larger and is situated at a higher altitude. It sends down several ice-tongues to the sea and is fringed by an extremely rugged coastal topography. Occasional calving is taking place, but the resulting icebergs are small. Crevasses are plentiful, indicating that the rock pedestal supporting the ice-cap has numerous surface irregularities. So far as is known, only a single nunatak, located west of Watt's Bay, projects above the ice-cap. The total longitudinal extension of the two units of the ice-cap is about forty miles. Their inland extension is not known but is, perhaps, less. The ice-cap receives its moisture from ascending air currents after the manner of a mountain glacier. It is, however, of sufficient size to develop local descending and centrifugally directed surface air currents for a part of the year. NEWELL SOUND; CHANGE IN COASTAL TOPOGRAPHY Our next stop was at Newell Sound, which is not at all as charted by Hall. Instead of a wide bay it is hardly a mile across at the entrance, and narrows still more farther towards its head. After the first point is passed, it turns southward and a narrow arm leads into a deep round bay which seems to extend south- westward. Altogether, it is about six miles long, judging from the running time of our motor skiff. It was getting dark when we entered this sound and we did not go ashore. The character of the coastal topography now differs from that previously seen. The hills are lower, more rounded, and relatively smoother, showing little dissection since the rounding (Fig. 18). Talus slopes are few or wanting and snowdrifts on the sides of the hills have practically disappeared. KOOJESSEE INLET AND SYLVIA GRINNELL RIVER; BAFFIN LAND ESKIMOS Next morning (August 15) we left our anchorage for Koojessee Inlet, tak- ing a circuitous course around Fletcher Island and through narrow channels among numerous islands off Becher Peninsula. The passage is difficult and dangerous, for it is obstructed by numerous reefs and rocky shoals over which cross-seas, at flood, rush in terrifying violence. It may never be attempted except on a clear day and then only if a very sharp lookout from the masthead can be maintained. The current is so strong and eddies are so numerous that a sailing vessel would make scarcely any headway against them. We were now within sight of the head of the bay. The land at this point assumes an undulating character and rises only to a slight elevation. Islands COASTAL GEOLOGY 39 are smaller, lower, and more numerous. The tide is thirty-eight feet and covers many of the low islands when at flood stage. Shortly after we anchored in Koojessee Inlet we went ashore and walked eastward over a narrow divide. Before we were halfway across we saw the Sylvia Grinnell River rushing over rapids into the bay. The river is not large, being hardly 300 feet wide at the rapids, but it is very swift and teems with large sea trout, some weighing as much as eight pounds. We also saw nearby an Eskimo summer camp of sealskin tents. The inhabitants, save for a man too old Fig. 18. Coastal topography near Newell Sound. The hills are lower, more rounded, and less severely dissected than those of the Everett Range (Fig. 15). to hunt, consisted of women and children only. The younger men had gone to the interior for caribou. Unlike the Labrador Eskimos, these people live as their fore- fathers did, closely guarding their ancient customs, habits, and traditions. NORTHERN LIGHTS It was nearly midnight when we returned to the ship. The moon was bright for the first time since we entered Frobisher Bay and the sky was illu- minated by a gorgeous display of the Northern Lights. The whole horizon was marked by varicolored beams of light rising toward the zenith. Vast flame-cur- tains opened and closed with inconceivable rapidity. Radiations of reds, greens, and yellows flickered like wind-driven smoke over the heavens. It was a rare spectacle, rare even in this latitude, for not once again did we see so many dif- ferent types of aurora — arcs, rays, bands, curtains, and others — appear simultane- ously. Auroras are believed to be caused by electric discharges of some kind, 40 ORDOVICIAN FOSSILS OF BAFFIN LAND the changes either coming from or being induced by the sun. Whatever the cause might be, the auroras invariably brought about a static condition, which seriously interfered with the operation of the ship's radio. BISHOP'S ISLAND We hoped to reach the head of the bay by sailing along the northeast coast but scarcely had we left the harbor than the water began to shoal and masses of kelp appeared on the surface. The course was, therefore, changed and we crossed diagonally over to the opposite coast where a good anchorage was found at the north end of Bishop's Island, nine miles from the head of the bay and Jordan Fig. 19. Tidal flats at the mouth of the Jordan River. River. The tide here rises to a height of forty-eight feet, the highest we had encountered in the bay. A great expanse of tidal flats (Fig. 19), which at low tides become bare for at least three miles, lies between Bishop's Island and the mouth of the Jordan River. The flats are marked by numerous boulders, reefs, and ledges which serve to set the rising and falling tides in different directions, creating cross-currents that are incredibly erratic and powerful. Perhaps we could have worked our way nearer to the head of the bay in the vicinity of Silliman's Fossil Mount — our next destination — by seeking some channels between islands, but it seemed that the risk involved in the attempt was not warranted by the small advantage that might have been gained. SILLIMAN'S FOSSIL MOUNT Next morning (August 17), taking advantage of the rising tide, three of us set out for Silliman's Fossil Mount in our outboard runabout. Our course lay between Preservation Island and several unnamed islands, where Hall experi- enced a "struggle for dear life." He described the place as "boiling and seething mill-races made by the tide as it rushed along." We met with strong cross-seas El m £ O I w c 3 ii ! c be I 60 £ s £ B 1 8 o "3 I O 2 o c p. aT > o C 3 O o fa d a 5 CO S3 a 41 42 ORDOVICIAN FOSSILS OF BAFFIN LAND and eddies but, on the whole, the journey was uneventful. Unquestionably, it is a treacherous stretch of water but may be considered safe at high tide. Silliman's Fossil Mount (Fig. 20), named by Hall after Benjamin Silliman, Jr., of New Haven, Connecticut, is, according to our observation, in 63° 43' N. Lat. and 69° 2' W. Long. It stands at the west side of the terminus of the bay, about 300 feet from high tide and two and one-half miles south of Jordan River. It is a longitudinal mount of horizontally bedded limestone which lies uncon- formably on the rocks of the hills of Meta Incognita. It is about three-fourths of a mile long, about 300 feet high, and extends in a general northwest and south- east direction. The mount is not continuous, but is broken in two places. The -V. -', - Fig. 21. Silliman's Fossil Mount, showing first break (southeast side) and nature of rock disintegration. first break (southeast side) is a deep V-shaped cut, but the apex of the V has not yet reached the base of the mount nor does it seem that it will do so in the near future. The stream that was responsible for the cut is now well filled up with debris and is practically inactive. The second break (northeast end) has been cut to the level of the base of the mount, and has been made by a smaller stream that winds down the valley between the Fossil Mount and the mountains of Meta Incognita and finally cuts its way through the mount, separating its northeast end from the main body. Hall called this separated portion "a smaller mount of the same character . . . but all in debris." Silliman's Fossil Mount is thus divided into three sections of which the first two are not yet completely separated. To these three sections, a fourth one, hitherto not mentioned by previous visitors, 1 may be added. This section lies behind the first section and extends in a parallel direction to a point as far as the V-shaped cut referred to 1 Charles F. Hall in 1861 and eight members of a party headed by Russell W. Porter in 1897. COASTAL GEOLOGY 43 above (Fig. 21). Here it ends abruptly as a steep wall. It is not a distinct unit although a deep trough partially separates it from the front ridge. The top of Silliman's Fossil Mount, with the exception of the third section (the lesser mount), is flat, table-topped, and covered with glacial erratics and reindeer moss. The lesser mount is bare and has disintegrated to such an extent that it is hardly more than a talus heap. Disintegration of the wall of the mount proper has also been extensive (Fig. 21). The debris, which dips at about 45°, has reached to within fifteen feet of the summit. Portions of the mount that are still intact show horizontal bedding but they too are rapidly crumbling and in some places breaking off in irregular columns (Roy, 1929). The best develop- ment of columns is in the uppermost beds at the southeast end of the mount (Fig. 20, c). The columns vary in width and in the number of faces, and are approximately perpendicular to the bedding plane, although some have an in- clination of several degrees to it. So far as observed, there were no evidences to indicate that the columns were developed either from concretionary action or from mud cracks. They are apparently the result of a joint system developed from tensional forces acting during the uplift of the area. Joints producing cubical blocks in stratified rocks have two directions, vertical and at right angles. In this case there is an additional diagonal direction which does not lie in the line of intersecting points of the vertical and right-angled joint planes. In such a joint system there would be a series of columns having from three to six faces. Ordinarily, the three-sided columns, being thinner and more angular, would disintegrate first, separating the other columns and increasing the columnar effect of the strata. Lithologically the limestone beds of Silliman's Fossil Mount vary slightly. At least three variations have been observed but due to the extreme disintegra- tion of the beds it has not been possible to determine whether they intergrade with one another or alternate. For the same reason it is impossible to collect PHYSICAL PROPERTIES AND CHEMICAL COMPOSITION 1 OF LIMESTONE BEDS OF SILLIMAN'S FOSSIL MOUNT Nature of bed Color Texture Hardness Sand and clay CaCoj MgCoj / Fe»0 8 \ AUO, Bed A Buff Very fine Hard 1.7 89.45 7.12 1.68 BedB Light bluish gray Shaly Medium 19.7 73.50 6.91 1.98 BedC Bluish gray with dark organic matter and fre- quently with pyrite Crystal- line Very hard 9.8 85.25 6.06 3.07 Analyses by Henry Herpers, formerly Assistant Curator of Geology. 44 ORDOVICIAN FOSSILS OF BAFFIN LAND fossils in stratigraphic sequence from these beds. With the exception of a few specimens of Maclurina and Maclurites (pp. 115-121) and a specimen of Westeno- ceras (pp. 141-143) which were found in situ at the top of the mount, all others described in this paper were collected from the talus slopes. The three variations of the limestone beds at Silliman's Fossil Mount are here called Bed A, Bed B, and Bed C. Their physical characteristics and chemical compositions are shown in the table on page 43. It has already been stated that the Fossil Mount lies unconformably upon the pre-Cambrian rocks of the Meta Incognita. The line of contact may be seen at the southwest end of the mount (Fig. 20). The rock upon which the limestone rests is a pink granite and not a mica schist, as was previously reported by Stevens (1863, p. 294) . The granite (Fig. 22) consists essentially of microcline (55 per cent), quartz (30 per cent), and albite (5 per cent). Chlorite, garnet, magnet- ite, and zircon are accessory minerals. The chlorite, as evidenced by the fresh- Fig. 22. Thin section of granite under- ness of all the other constituent minerals lying Silliman's Fossil Mount. fe not the result of secondary alteration but is deuteric. The absence of mica and other ferro-magnesian minerals is a rather unusual feature of this granite. It may be of interest to reiterate that the mount constitutes the only sedi- mentary formation observed in place throughout the entire region of the bay, which is nearly 150 miles long and about 50 miles wide at its entrance from Davis Strait. The existence of such an isolated hill of limestone can be inter- preted in several ways but the two most plausible explanations seem to be that the mount is either an erosion remnant of the deposits laid down on the irregu- larly eroded pre-Cambrian surface in the Ordovician and later seas or the result of the erosion of sediments from a graben developed during post-Ordovician- Devonian faulting. The latter interpretation is the more likely since an isolated deposit such as Silliman's Fossil Mount is seldom an erosion remnant. Previous to our visit to Silliman's Fossil Mount, two other parties had collected fossils there. The first collection, consisting of seven species, was made by Charles F. Hall in 1861; and the second one, consisting of seventy-one species, by a party of eight, headed by Russell W. Porter, in 1897. In addition to these two collections, a third one, believed to have been made by the Eskimos at the mount, was brought to this country by G. Cromer of Boston. The circum- stances under which Cromer secured the fossils, consisting of fourteen species, are not known. Information regarding these collections is given on pages 182 to 188. Our collection, representing 68 genera and 116 species, is by far the largest. It was our intention to make a more exhaustive collection and to trace the course of the Jordan River northwards into the unexplored interior but unmistakable COASTAL GEOLOGY 45 signs of winter appeared suddenly and we had to abandon our plan. On the three succeeding mornings the boat had to be freed from the bay ice and we were afraid we might not be able to get out to the open sea if we delayed longer. FLETCHER ISLAND AND ESKIMO RUINS; GLACIAL STRIAE Our return journey began on August 19, three days after reaching Bishop's Island — the farthest point that could be safely reached by a boat drawing ten feet of water. Stopping overnight at Eggelston Bay and for a few hours at Fletcher Island, we sailed across the bay and entered Ward's Inlet where we dropped anchor under the lee of an unnamed island at Edmond Point. At Fletcher Island we found several rock beacons built in the form of crosses of natural slabs. As beacons they are effective, but it is not quite clear why they were erected on this particular island when there are several higher islands close by. Most of the larger islands in Frobisher Bay contain such old Eskimo ruins as cairns, meat caches, tupik rings, stone and sod igloos and various types of artifacts, and they therefore offer a promising ground for those interested in the study of the stone age culture of the north. Glacial striae are not as common on the coast of Frobisher Bay as on that of Labrador, but their occurrence was observed on several islands near the head and middle of the bay. Our halts on these islands, however, were brief, and we were not always prepared to take accurate readings of the directions of the striae. The few meas- urements that were taken varied but, in the main, the striae followed the axis of the bay, indicating that the ice came from the northeast. It cannot, however, be stated at present whether or not this direction of ice movement was regional or local. The data at hand regarding the direction of striae, being restricted only to certain islands, can scarcely form the basis of a definite conclusion. WADDELL BAY; FLUVIO-GLACIAL DEPOSITS Our next anchorage was at the head of Waddell Bay, facing an elevated beach about 120 feet high. Directly behind the beach is an old glacial valley which extends in a general northeast-southwest direction inland for several miles. The valley is a veritable storehouse of fluvio-glacial material and was easily the most desirable place we had visited during our cruise for studying in a practical way different types of glacial forms in their natural environment and in their natural relations to one another. BREWSTER POINT; DRIFT FOSSILS Near noon, on August 22, we hove up and left Waddell Bay, heading down the coast between Dudley Field Island and the mainland. The weather was clear over Meta Incognita (opposite coast) and once again as we passed through the channel between Gabriel and McLean Islands and veered to northeast for Brewster Point we saw the ice-cap and three tongues reaching out to sea. A maze of small islands and reefs, most of which become submerged at high tide, lies at the entrance to Brewster Point, but we managed to thread our way between them and dropped anchor in seven fathoms of water in a cove in front of a trad- 46 ORDOVICIAN FOSSILS OF BAFFIN LAND ing post. We did not know to whom the post belonged but apparently it was not abandoned. This was the first little house we had seen and perhaps the only one to be found around the bay. Inside the house were a number of white and blue fox skins and in the front yard stood a huge vat filled with walrus tusks. We were tempted to take a pair of tusks but we dared not, perhaps because we could not bring ourselves to violate the time-honored, unwritten law of the North. Drift fossils in limestone on the hills along the coast are not uncommon, but here and a little northwest of here, in Barrows Peninsula, they seemed to occur in great abundance. These fossils are also of Ordovician age but their occurrence Fig. 23. Kodlunarn Island, the site of Frobisher's proposed colony. at an altitude between 1,000 and 2,000 feet or more would seem to indicate that they were brought down by the last continental ice-sheet from the interior rather than from Silliman's Fossil Mount. KODLUNARN ISLAND; RELICS OF SIR MARTIN FROBISHER The next morning (August 23) broke calm with thick fog but before long a sudden offshore breeze cleared the fog and we got under way with foresail and jib. Three hours of sailing brought us to Countess of Warwick Sound and Kod- lunarn Island — the historic site of Captain Martin Frobisher's proposed colony. We spent the afternoon and the following morning on the island going over the relics which Frobisher had left behind some 350 years ago — almost half a century before the Pilgrim Fathers ventured from their island home to found Plymouth Colony. For a moment the mists of time were parted. The almost legendary beings who faithfully followed the great captain through perilous seas and icy wastes stood before us in the guise of mortal men. Kodlunarn Island (Fig. 23) is situated at 62° 47' 30" N. Lat. and 65° 10' W. Long., about thirty-five miles northwest of the entrance to the bay. The island, as is shown by raised beaches, has risen some fifty feet since Pleistocene time. Fig. 24. Top, long excavation on the north shore of Kodlunarn Island. It may have been one of Frobisher's mining trenches or it may have served as a dry dock for repairing small vessels. Bottom, another excavation, probably used as a reservoir for fresh water. 47 48 ORDOVICIAN FOSSILS OF BAFFIN LAND Its rocky surface, less than twenty-five acres in area, is without fresh water, and supports no vegetation other than trailing ground willows, lichens, and reindeer mosses. The place is so incredibly desolate and offers so little protec- tion from the rigors of the weather that a more forbidding place for setting up a colony is hard to imagine. On the north shore of the island, we found a deep canal about 110 feet long, 15 feet wide, and 25 feet deep (Fig. 24). The canal may have been one of Frobisher's mining trenches but it probably served as a dry dock for repairing small vessels. Southeast of the trench we saw a similar but smaller excavation, probably used as a reservoir for fresh water (Fig. 24). The ruins of two furnaces with evidences of old fires and clinkers in them were found between these two excavations. The furnaces were apparently used for assaying the so-called "gold ore." Near the center of the island, the foundation of the experimental house is still recognizable, in spite of the fact that the natives had been picking up what- ever took their fancy. Digging around it we found pieces of plaster, brick, porcelain, lime, coal, and flint stones (Fig. 25). The latter were doubtless used for "strike-a-lights." On the east side of the island, facing the sea, we found a sort of crude stone breastwork such as the Eskimos erect for shelter when hunt- ing. It may have been built to serve as a fortification against the natives. Near this stone structure, and most interesting of all, we noticed a small heap of rocks (Fig. 26), some of which fitted the description, "much like sea cole in colour." These rocks are foreign to the island, and, as shown by the growth of mosses and lichens over them, they have not been disturbed since Frobisher's time. The "sea cole colour" of some of the rocks (Fig. 26), their transportation from else- where, and their accumulation on the edge of the island whence they could be readily loaded into the ships' holds, suggest that they were the few remainders of the thirteen hundred tons of "gold ore" which Frobisher's men dug up on their last voyage and carried across three thousand miles of storm-tossed seas to swell the rock piles of England. FROBISHER'S "GOLD ORE" In reality, the "gold ore" is amphibolite (Roy, 1937, pp. 35-37), consisting essentially of hornblende (80 per cent) and augite and omphacite (10 per cent). Calcite, sodic plagioclase, biotite, magnetite, ilmenite, and titanite, with a sprin- kling of quartz, apatite, garnet, and zircon compose the remaining 10 per cent (Fig. 26). The calcite fills the interspaces and was produced by the alteration of the garnet. No pyrite, which has probably precipitated more "gold rushes" than any other mineral, is present. The logical conclusion, therefore, is that it was not the pyrite but the bronzy lustered mica, specks of which the rock contains, which was the real basis upon which Signor Agnello succeeded in perpetrating one of the most amazing hoaxes in the history of maritime adventuring. LUPTON CHANNEL Our visit to Kodlunarn Island and further search for the relics were cut short by the unexpected appearance of a herd of walrus in the bay. Our need for meat I fc VJ * \ Fig. 25. Top, hunting for relics in remains of Frobisher's house.- Bottom, relics (chips of bricks, flint, coal, tile, and mortar) of Frobisher's house on Kodlunarn Island. 49 50 ORDOVICIAN FOSSILS OF BAFFIN LAND for the sledge dogs during the coming winter was pressing, so we left the little island with its silent monuments of human courage, industry, and greed, earlier than we wished. Head winds and a choppy sea hindered our progress and we could never have caught up with our anticipated victims had not the stupid animals turned around and made for the boat. As they approached within striking distance we shot and harpooned a large cow and, using dory tackles, managed to hoist her up on the deck. We then steamed down the bay for a few miles and swung northeast through Bear Sound and Lupton Channel, entering the broader waters of Cyrus Field Bay. Lupton Channel, which lies between Cyrus Field Bay and Frobisher Bay, is frequently used by Eskimos to enter the latter. It is a narrow, crooked pas- sage between cliffs and reefs with a bold island near the middle of the south entrance. Powerful and erratic currents prevail in this channel, making naviga- tion difficult and dangerous. Vessels of any considerable draft should not attempt to pass it at either low or high tide. Wreckage of a whale boat and of a schooner was seen alongside a narrow reef in the channel. RETURN JOURNEY TO LABRADOR Our return journey now actually began and as we veered eastward to Davis Strait a gorgeous sunset brightened the horizon. Monumental Island loomed up in crimson and gold. Dark and desolate Lok's Land faded into the night. Sea watches were on; a following breeze filled the canvas; we turned south, reaching our winter quarters at Anatalak Bay, Labrador, three days later, on August 27. Labrador seemed warm in comparison to our sojourn in Frobisher Bay, but soon the whizzing hordes of insects yielded place to snow and sleet, and, before we had time to realize it, winter came with its biting wind and killing cold. The landscape turned to a vast solitude of glimmering whiteness. Snowshoes and dog teams became our means of transportation. Sledging, however, is no adventure. On the contrary, it is hard work — run and walk, ceaseless watch- ing of the weather, never knowing when a blizzard will strike and blind the view ahead and the trail behind. But despite adverse conditions, the lure of the Arctic is irresistible. It is probably unnecessary to mention that little field work in geology or paleontology can be done in Labrador during the winter. Apart from the fact that most of the land is covered with snow and ice, the rigor of the climate alone makes prolonged exposure in the open difficult, if not impossible. Winter, however, is the most favorable time for making observations on the work of snow and ice. MOVEMENT OF BOULDERS BY ICE One of our observations of the work of snow and ice was that of the move- ment of boulders of great size, some weighing several tons. The process by which the boulders are moved is very simple; indeed it is so simple that one is likely to overlook it, and generally does. Because of the stormy character of the region, much of the snow that falls during the winter is blown away quickly but there is Fig. 26. Top, a pile of lichen-covered rocks, the supposed gold ore. Bottom left, macro-texture of one of the above rocks; right, thin section of the same rock. 51 52 ORDOVICIAN FOSSILS OF BAFFIN LAND always some that drifts in behind boulders, particularly the larger ones. As the snow consolidates and freezes, it expands and the force thus exerted tilts the boulders a little. This creates a space into which sand grains, driven by the wind, and small pebbles are lodged. On warmer days the ice thaws but the pebbles and sand grains serve as a block preventing the boulders from falling back into their original position. The process just described repeats itself many times during a single season, and little by little the boulders are moved farther and farther. To be sure, the process is extremely slow but it is also extremely effective. The boulder shown here (Fig. 28) was observed to move about five inches during 1927- 28. Eventually it may reach a slope and roll down, by gravity, into the valley below. DOMED LAKES Another interesting phenomenon that we observed was the doming of lake ice. When the water and land freeze solid, the surface of the ice of certain lakes resembles an overturned bowl. The dome may reach an elevation of twenty feet or more above the summer water level. The cause of the doming is not clear. A possible explanation is that the expansive force developed by the freezing of water is unable to overcome the resistance offered by the solidly frozen banks of the lake. It therefore finds release by reacting as a compressional force on the ice, resulting in its doming in a manner somewhat like that in which certain rocks are folded. ICE MOUNDS Still another interesting phenomenon observed was that of the formation of ice mounds behind boulders on beaches (Fig. 28). The mounds frequently reach a height of twenty feet. There are many boulders which because of their shape or the position in which they lie on the ground are not carried away by the ice. Such boulders when they are within reach of the tide waters become covered with a coat of ice. The ice increases in thickness with each change of tide until a point is reached when it breaks loose and is lifted up by the tide, creating a void in which a new cap forms and pushes the old one up. Thus, every few days, a new cap is formed and the older ones are forced up until the mass becomes so great that it can no longer maintain its weight and rolls down the sides of the boulder. In this manner huge mounds of ice are built up. Ice mounds are very numerous and they often form a barrier in the entrances to bays. "DRIFT" SNOW A constant topic of conversation during the winter in Labrador is that of the "drift." The term "drift," as used by the natives, is not what we generally call snowdrift but is a living, moving mass of powdery snow dust that has been picked up and carried along by the wind. Very often it reaches a height of ten feet or more. No one dares to go out into it, for to do so is almost certain suicide. Objects within arm's length cannot be seen. In it one loses all sense of direction; pathways that may be followed on the darkest night become strange and unfa- miliar. When accompanied by strong wind it cuts like a sand blast and facing Fig. 27. Top, expedition's winter quarters; bottom, a typical Eskimo house. 53 54 ORDOVICIAN FOSSILS OF BAFFIN LAND it is all but impossible. The dust is so powdery that it enters the very smallest opening and packs solidly inside the clothes. The power of its erosion can scarcely be exaggerated. In a single night it polishes the sea ice until the smooth- est of new ice seems rough by contrast. It brings out, as no tool of man can do, the grain of the wood on the houses that are exposed to it, and it shears the shoots of small plants that grow in the clefts of mountains and rise a few inches above the rocks down to a level as uniform as the top of the best-kept hedge. Geologically, this so-called "drift" is a most effective agent of destruction. Not only does it eat away the softer minerals, exposing the harder ones to the weather, but it also enters the minutest pores and cracks in rocks where it freezes, loosen- ing their component parts and paving the way for their later disintegration. "QUOR" WATER Of all phenomena relating to ice and snow that we had the opportunity to observe, the most interesting was the presence of fresh, flowing water on the beaches and nearby areas at air temperature many degrees below freezing. This water is known locally as "quor" water. What the term means is not known unless it be the degenerated form of the word "queer," but to find flow- ing water when even the swiftest brooks have frozen to a depth of a foot or more is perplexing. Early in the summer when we were looking for a suitable site for our winter quarters, one of our prime considerations was to insure a good supply of water at all seasons. With this idea in mind, we always inquired about it in each place that appeared to us otherwise promising. We were told that we could get all the water we should need if we dug but a few inches below the surface of the ice on any of the brooks but that if the winter was very severe and the ice was too thick to break through to reach water, we could always get plenty of "quor" water. At that time we could not quite understand what "quor" water might be, nor do we understand much more about it now, except that it is a source of water that can be obtained with little or no effort. Apparently, it is some form of seepage from considerable depth below the level of the frozen ground, where circulation of water is possible. Yet it is difficult to explain why the water should collect in streams and flow out on the accumulated ice without freezing during emergence from such a depth at temperatures many degrees below the freezing point. It may be that the hydrostatic head is sufficiently high to exert the pressure needed to account for the phenomenon. Although "quor" water is a great blessing as a source of abundant drinking water, and although it eliminates the laborious process of obtaining water by quarrying and melting ice, it is also a real menace. Because of the constant seepage, the snow is kept so mushy that it is extremely difficult, and often impos- sible, to walk along the beaches, where the "quor" water seems to be more prevalent than elsewhere. Wet feet, when the temperature is hovering around 30 degrees below zero, are likely to freeze without warning. The situation assumes serious proportions, however, when "quor" water appears near dwelling Fig. 28. Top, ice mound formed by tide waters; bottom, a huge boulder moved five inches during a single season by the work of ice. 55 56 ORDOVICIAN FOSSILS OF BAFFIN LAND houses. During the winter of 1927-28, "quor" water filled the sawmill at Nain to a depth of many feet and entered a number of houses, forcing the occupants to abandon them. In late spring when the owners returned they found ice as much as three or four feet thick in their living rooms. In the neighboring villages, some houses were completely buried. The examples of the work of snow and ice briefly stated herein are a few of the many that may be observed during the winter. The purpose of recording them is to stimulate further investigation on the subject by those who may have occasion to spend a winter in Labrador. DESCRIPTION OF FOSSILS INCERTAE SEDIS Family Receptaculitidae Roemer Genus Receptaculites DeFrance The genus Receptaculites was established in 1827 by DeFrance (Diet. Sci. Nat., 45, p. 5, pi. 68), who compared the rhomboidal outer plates of the organism to the arrangement of the scales of a pine cone, although in his final analysis he believed it to be a coelenterate of some kind. Since DeFrance's time various investigators have studied the morphology of this genus and attempted to determine its systematic position but with widely varying results. Among those (Goldfuss, Eichwald, Salter, Billings, Dames, Gumbel, Roemer, Rauff, and Hinde) whose names stand out prominently in this connection, Billings and Rauff seem to have seen more clearly, particularly as to the nature of the complete forms of the organism. 1 The Baffin Land Receptaculites described and figured in the following pages add little to the solution of the uncertainties surrounding the taxonomy of the group. It would, therefore, be hardly profitable to give here a resume of the divergent opinions of all the authors just mentioned. Two specimens (F.M. Nos. P28822, P28823), however, do help to clarify certain fundamental morphological features of the genus and may be briefly discussed here. Billings believed that Receptaculites possessed a variable form with a covered summit and a central cavity. He (1865, p. 379, text fig. 353) observed: "The genus may be described as consisting of organisms which, when full grown and perfect, are of a discoid, cylindrical, ovate, or globular shape, hollow within, and usually, if not always, with an aperture in the upper side." He (p. 379) further added: "The flat watch-shaped specimens which are usually figured as constituting the whole of the body, are probably only the basal portion of the body-wall of the discoid species." Hinde (1884, p. 821) disagreed with Billings' interpretation and asserted: "There seems no evidence in favor of the supposition of Mr. Billings that the complete specimens of this genus possessed dome-shaped or conical summits similar to those of Ischadites, for though platter and cup- shaped examples are abundant in certain strata, and apparently perfect as regards their outer form, yet in no single instance has an upper portion been discovered in connection with them; and if we take into consideration the num- erous instances in which the smaller and more delicate forms of Ischadites still retain their complete form and conical summits, the conclusion appears justi- fiable, as Gumbel has already remarked, that the specimens of Receptaculites were originally of the form in which they are now found as fossils. No specimen 1 It might be desirable to investigate the possibilities of relationship between the Receptaculitidae and the Archaeocyathinae. Superficially there are certain similarities, the most apparent of which is that the skeletons of both are double-walled. Furthermore, the intervallum (the space between the walls') in both is crossed by rod-like structures. For detailed discussions on the Archaeocyathinae, see T. Griffith Taylor, Mem. Roy. Soc. South Australia, 2, pt. 2, 1910; and P. E. Raymond, Bull. Mus. Comp. Zool., 9, No. 6, pp. 172-177, 1931. 59 60 ORDOVICIAN FOSSILS OF BAFFIN LAND has yet been found to correspond with the diagrammatic representation which Mr. Billings [1865, p. 378, text fig. 353] has given of a supposed complete example of the genus." Rauff (1892, pp. 8, 9) maintained that Receptaculites possessed Fig. 29. o, c, Vertical sections of discoid specimens of Receptaculites and Ischadiles respectively, showing nature of curvature of peripheral walls, b, Vertical section of a nearly complete specimen of Ischadites iowensis, showing the bell-shaped central cavity, d, A nearly complete specimen of Ischadites iowensis in which the conical upper portion is pre- served, e, Discoid form of Ischadites iowensis. All natural size. a spherical or pear-shaped body with a central hollow and a completely closed summit. He was also of the opinion that the disk-shaped specimens of Recep- taculites are only fragments of originally closed forms. Rauff's observations, DESCRIPTION OF FOSSILS 61 thus, are in accord with those of Billings except that the latter thought that the summits were not completely closed but that they had usually, if not always, small apical apertures. The two Field Museum specimens, though not complete, substantiate Billings' and RaufFs observations, especially as to the presence of an upper portion. The larger specimen shows clearly that it was subcorneal (fig. 32, a) with a subcircular base (fig. 32, c). Its vertical section (fig. 32, b), like that of Billings' diagrammatic representation (1865, p. 378, text fig. 353), reveals a large, rapidly converging central cavity. The smaller one, with the extremity preserved, is pear-shaped with a bent neck (fig. 33, a). It also shows a rapidly converging cavity. Both of these specimens resemble Ischadites in external form but possess an inner integument, which is a diagnostic character of Receptaculites. There are good reasons to believe that Billings and Rauff were correct in suggesting that disk-shaped specimens of Receptaculites are only the basal portions of once complete individuals, but positive data are not available to prove whether the summits were closed or open. This conclusion is based not only on specimens 1 which have actually retained the upper portions, but also on the manner in which the preserved portions of the peripheral walls of all discoid (hence incomplete) specimens are curved (fig. 29, a). This curvature is such that it is difficult to conceive of any possible manner by which the peri- pheral walls may have terminated other than by continuing upwards and forming some sort of upper covering. Further strong analogical evidence may be drawn in support of this view from specimens of Ischadites iowensis (Owen). Nearly all specimens of this species are preserved in the discoid form (fig. 29, e), as are those of Receptaculites, but some nearly complete forms (fig. 29, d) have been found with conical upper portions and bell-shaped central cavities (fig. 29, b), showing clearly that the discoid specimens of J. iowensis are only incomplete basal portions. Furthermore, the peripheral curvatures of discoid forms of /. iowensis (fig. 29, c) which are known to have possessed upper portions are almost identical with those of discoid specimens of Receptaculites (fig. 29, a), suggesting that what is true of the former was in all probability also true of the latter. NOTES ON THE TERMINOLOGY OF RECEPTACULITES So many different terms have been used by different writers to describe the same structural components of Receptaculites that it is impossible to become familiar with them without perusing voluminous literature. Therefore, for the convenience of those interested in this genus, there is appended a table giving terms and synonyms used by various authors, with a brief explanation of each. In describing the three following species of Receptaculites, the self-explanatory and hence simpler terms used by Hinde have been employed. It is, however, not to be concluded that the terms used by other authors are inappropriate. 1 The specimens were collected by Dr. E. O. Ulrich and are now in the United States National Museum. 62 ORDOVICIAN FOSSILS OF BAFFIN LAND TERMINOLOGY USED BY VARIOUS AUTHORS TO DESCRIBE STRUCTURAL PARTS OF RECEPTACULITES Brief explanation of different terms is given in the last column E. Billings * W. Dames C. W. Gttmbel G. J. Hinde H. Rauff Explanation Ectohorin Outer layer Aussenflache Outer surface (fig. 30, a) Spicules Merome Component structural parts of the body-wall Rhomboidal or hexagonal plates of the ectohorin Rhomboi- dische Tafeln Rhombische Plattchen Head or summit plate Tafelchen Plates of the outer surface (fig. 30, b) Stolons Kanale Epistyle Stutzarme Horizontal rays Tangential- arme Four horizontally ex- tended arms or rays immediately beneath the head-plate (fig. 30, c, d, e, f) Radial stolon Radial centripetaler Ast Proximal angle and ray DistalerArm That horizontal ray which points inwards toward the nucleus (fig. 30, c) Radial stolon Radial centrifugaler Ast Distal angle and ray Proximaler Arm That horizontal ray which points towards the periphery of flat- tened specimens or to- wards the summit of conical specimens (fig. 30, d) Cyclical stolons Concentri- sche Aestchen Lateral angles and rays Lateral- arme The two horizontal rays which project at right angles to the direction of the proxi- mal and distal ones (fig. 30, e, /) Cylindrical tube or hol- low spicule Cylindri- sche Rohre Saulchen Vertical ray Saulchen or Columell Subcylindrical arm or ray extending at right angles to the horizon- tal rays towards the in- terior, reaching to the inner layer (fig. 30, g) Endohorin Innere Hiille Inner layer Innenflache Inner surface (fig. 30, h) * With the exception of the term "cells" for "cylindrical tubes" of Billings or "vertical rays" of Hinde, American authors have generally followed the terminology of Billings. DESCRIPTION OF FOSSILS 63 b c Fig. 30. Diagrammatic representation of component parts of body-wall of Receptacu- lites (modified after Salter and Billings), a, Outer layer, b, Head plate, c, Proximal angle and ray. d, Distal angle and ray. e, f, Lateral angle and rays, g, Vertical ray. h, Inner layer, i, j, Weathered surface (inner), showing plates, k, Free ends of vertical rays. Receptaculites sp. Description. — Subcircular in outline with incurved margins. Maximum diameter 117.5 mm. (4^§ in.). Approximately two-thirds of the basal outer surface depressed, in or near the center of which is situated the so-called nucleus, which is small and conical. Summit of nucleus well below level of adjacent higher surface. Head-plates rhomboidal but not easily recognizable, radiating outwards to the peripheral margins in curved lines from the nucleus. The character of the vertical rays cannot be clearly seen; they vary considerably in length and width, being short and wide at and near the nucleus, becoming longer and narrower as they approach the incurved margins. The total thickness between the inner and outer walls is 6 mm. at the nucleus, 12 mm. at the margin. Neither the canal system nor the horizontal rays are distinguishable, both having merged into a wavy layer of calcite above (inner layer) and below (outer layer) respectively. Remarks. — This form may be related to or even be conspecific with the one described by Etheridge as "Receptaculites arcticus" (probably not a valid species). It is, however, not definitely identified here for two reasons: (1) The outlines of the vertical rays are not clear; and (2) the definite specific characters that distinguish R. arcticus from R. occidentalis Salter and R. oweni Hall have not been satisfactorily recognized. Size cannot be regarded as a specific character nor can the forms of the head-plates, for these vary considerably in the same specimen. The horizontal rays as well as the canal system are rarely seen and, even if present, they help but little in specific differentiation. The only other important structural component of the spicule is the vertical ray, apparently with two distinct types: one with constriction at one end, next to the horizontal rays; the other spindle-shaped, constricted at both ends. Both types, however, may occur in the same specimen although one or the other is usually predominant :'> ■•V w,\ A ill Fig. 31. Receplaculites sp. F.M. No. P28821. a, Basal outer portion of an individual. b, Vertical section of the same through the nucleus, c, d, Weathered fragments of two different individuals, showing plates of outer surface and free ends (inner side) of vertical rays, respectively, e, f, g, Fragments of body-walls from different parts of one or more individuals, showing variations of forms of vertical rays. All natural size. 64 DESCRIPTION OF FOSSILS 65 — a feature which may be regarded as a good specific character providing that the specimen is fairly complete and a good portion of it can be examined. The width of the vertical rays, however, is no positive criterion for specific separation. Fig. 31, b, clearly demonstrates how the width varies, being much wider adjacent to the nucleus than at the margins. The length, of course, in all cases corresponds to the thickness between the walls and has no value in this connection. The spacing of the vertical rays also may not be regarded as a good specific character, for it too varies in different portions. Obviously, then, it is almost impossible to make correct identifications of fragmentary specimens of Receptaculites. Inasmuch as most specimens are found in this condition an overburdened litera- ture has unfortunately accumulated. The illustrations (fig. 31, e, f, g), showing fragments of different individuals with diverse shape and size of the vertical rays, even in the same specimen, give an adequate idea of the difficulty in which the investigator finds himself when attempting to make positive identifications. Winchell and Schuchert (1895, p. 59) distinguished R. oweni from R. occidentalis by "the greater size attained by R. oweni, and the plates of the inner surface having twelve canals instead of four, as in R. occidentalis, a central knob on each head-plate of the spicules on the outer surface of the former . . . ." I have examined a large number of specimens of R. oweni but in no instance have I been able to see the "twelve canals" on the inner plates. In fact, in no specimen that I have examined are the inner plates sufficiently well preserved to examine the canal system satisfactorily. It would seem taxonomically un- likely, however, for two closely related species to be distinguished by so striking a character as the presence of twelve canals in one as against four in the other. The "central knobs" on the head-plates are probably not structural features at all but are results of a peculiar condition of preservation. At least they are not observable on the great majority of specimens. The important differences between R. oweni and R. occidentalis seem not to be those previously emphasized but rather to rest in the shape of the vertical rays. In the former, the vertical rays are predominantly spindle-shaped, cylindrical in the middle and contracted both above and below, whereas in the latter they are contracted only below, next to the horizontal rays. This difference, however, cannot always be relied upon, especially when it is a question of identifying fragmentary material, for, as discussed above, both types of vertical rays may appear in the same specimen. According to the original description of Etheridge (1878, p. 576) R. arcticus differs from R. occidentalis in having "tubuli [vertical rays] more glass- or spindle- shaped, much more so than in R. occidentalis, where they are nearly columnar; the upper ends or terminations of the tubes [vertical rays] do not appear to expand so much as in R. occidentalis . . . ." From Etheridge's description it would seem that the vertical rays of both R. arcticus and R. oweni are similar. The work of Hinde, however, makes this conclusion untenable. In his descrip- tion of Etheridge's types of R. arcticus in the British Museum he (1884, p. 845) stated: "The vertical rays, like those of R. occidentalis, are contracted immedi- ately beneath the horizontal rays and then expand again and continue of an even thickness to their junction with the inner or upper plate." Unfortunately, 66 ORDOVICIAN FOSSILS OF BAFFIN LAND neither Etheridge nor Hinde supplemented his description with illustrations. It is, therefore, impossible to ascertain from the literature alone which of these two writers is correct. If the vertical rays of R. arcticus are similar to those of R. occidentalis then the former is more closely related to the latter than to R. oweni; if not, then the reverse is true. In summing up : R. occidentalis and R. oweni are two distinct species which can be recognized by their vertical rays when well-preserved specimens are available, whereas R. arcticus is probably synonymous either with R. occidentalis or with R. oweni, depending on whether Etheridge or Hinde was correct. If R. arcticus is a distinct species it will have to be based on characters other than those mentioned in the literature. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Receptaculites (?) fieldi Roy, sp. nov. Description. — Conical as preserved; basal outline subcircular. Central cavity in vertical section triangular, gradually converging. Average space Fig. 32. Receptaculites fieldi Roy, sp. nov. F.M. No. P28822. o, Upper portion. b, Vertical section, c, Basal surface (polished). All natural size. between outer and inner layers about 6 mm. Head-plates not clearly seen. Vertical rays slender, narrow but not constricted next to the horizontal rays, expanding gradually towards the inner layer. Diagnosis. — The only described species of a closely allied genus which it resembles most in external form is Ischadites koenigii Murchison (R. I. Murchison, Siluria, 1854, pi. 12, fig. 6; Receptaculites jonesi Billings, 1865, p. 385, fig. 363; also Hinde, 1884, pi. 36, fig. 1, a) but the present species has a distinct inner DESCRIPTION OF FOSSILS 67 layer and the central cavity is not bell-shaped but gradually converging. The body-wall of the present species also is of more even thickness — a feature which is not usual among the known species of Receptaculites. Remarks. — The basal outline, which is not quite circular, indicates that the completed form of this species was not exactly conical but was slightly bent on the relatively straight side of the basal circumference. The specific name is in honor of Mr. Stanley Field, President of Field Museum of Natural History. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Holotype.—FM. No. P28822. Receptaculites sp. Remarks. — Only a part of the upper portion of this form is in the collection. Its original entire form, as can be judged from the preserved portion, was pear- Fig. 33. Receptaculites sp. F.M. No. P28823. a, Upper portion, b, Vertical rays, c, Cross section showing inner layer and central cavity. All approximately X 2. shaped with a bent neck, somewhat like a crookneck summer squash. It closely resembles the published figures of Ischadites murchisoni Eichwald in general outline but structurally it is a Receptaculites, since it has a distinct inner layer (fig. 33, c). The head-plates are more quadrangular than rhomboidal and have more or less curved sides (fig. 33, a). The vertical rays are cylindrical, con- stricted next to the horizontal rays (fig. 33, b) in the manner of those of R. occi- dental Salter. The central cavity converges rather rapidly but, since the tip of the summit is not preserved, it is not known if the cavity extended throughout to end in an apertural opening. 68 ORDOVICIAN FOSSILS OF BAFFIN LAND This specimen is too imperfect to serve as a type but it is unlike any described species of Receptaculites and doubtless represents a new species. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Phylum COELENTERATA Class Anthozoa Subclass Tetracoralla Family Zaphrentidae Edwards and Haime Streptelasma spp. I, II, and III Remarks. — There are at least three different species of Streptelasma in the collection. Unfortunately, however, none of the specimens representing these species is entire, nor are there more than two specimens of each kind. It has thus been difficult or impossible to make specific identifications. m y'T" Fig. 34. a, b, c, Streptelasma sp. I. F.M. No. P28824. a, b, Lateral views, c, Trans- verse section of a different individual, d, Streptelasma sp. II. F.M. No. P28825. e, f, Streptelasma sp. III. F.M. No. P28826. Lateral views of two different individuals. All natural size. Streptelasma sp. I is probably allied to S. breve Winchell and Schuchert. It is a small, rapidly expanding form, but because the specimens representing it are not entire, exact dimensions cannot be given. The calyx is slightly ovate in cross section, the longer diameter being 16 mm. and the shorter 14 mm. Septa long and short with about forty of each kind. Surface marked by faint longitu- dinal ribs and crossed by closely set concentric lines of growth. Streptelasma sp. II has a short, conical form with a median keel and two lateral ones. The calyx is circular, having a diameter of 25 mm. at a distance of about 28 mm. above its apex. This form may be related to S. robustum var. amplum Troedsson, from the Cape Calhoun beds, Cape Calhoun, Greenland. DESCRIPTION OF FOSSILS 69 Streptelasma sp. Ill is much like S. comiculum Hall. The specimen is about 40 mm. long, conical, and expanding gradually from a pointed base. Calyx circular, having a diameter of about 22 mm. at a distance of about 30 mm. above its apex. Septa alternately long and short, about 100 in all. Surface marked by rather strong longitudinal ribs and crossed by both conspicuous and inconspicuous wrinkled concentric lines of growth. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collectors. — John Jaynes, Ralph Robinson, and Sharat K. Roy. Family Cyathophyllidae Edwards and Haime Genus Favistella Hall Favistella sp. Only a fragment of a corallum representing this form was collected. The specimen, however, was mislaid and cannot now be found. At present it is represented by two cross sections and one longitudinal (rather inclined) section. Fig. 35. Favistella sp. F.M. No. (considerably inclined) section; x 4M- P28827. o, Cross section; X 4. b, Longitudinal Description. — Corallum composed of polygonal corallites in contact with one another. Diameter of corallites varies from 3 to 6 mm. Septa about twenty-six in number, alternatingly long and short, the former strong and extending almost 70 ORDOVICIAN FOSSILS OF BAFFIN LAND to the center, the latter mere vertical ridges along the corallite walls. Tabulae horizontal or slightly concave. Remarks. — Inasmuch as the specimen representing this form is lost, it has been deemed desirable not to identify it with any described species from thin sections alone. The sections, however, closely resemble those of Columnaria (Favistella) alveolata Goldfuss. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Subclass Alcyonaria Family Heliolitidae Lindstrom Subfamily Plasmoporinae Kiaer Genus Plasmopora Edwards and Haime Plasmopora lambei Schuchert Plasmopora lambii 1 Schuchert, Proc. U. S. Nat. Mus., 22, p. 154, 1900; Hume, Mem. Geol. Surv. Canada, 145, pi. 5, fig. la, b, 1925; Troedsson, Medd. om Gr0nland, 72, p. 118, 1928 (in part; probably only pi. 32, fig. 1, specimen No. 691) ; Teichert, Rept. Fifth Thule Exped., 1921-24, Gyldendalske Boghandel, Nord. Forlag, 1, pp. 53-54, 1937. Original description (Schuchert, 1900, p. 154). — "This species begins growth on some small foreign object, and expands to a diameter exceeding 12 cm. by 7 cm. in height. Beyond the place of attachment the lower surface is irregularly concave and covered by a thin epitheca. The upper surface is in form depressed hemispheric to conical. Corallites from 1 to 1.75 mm. in diameter, commonly about 1.25 mm., circular, and separated from one another from 0.5 to 1.25 mm. Septa not prominent, and where the original surface is well preserved not easily distinguishable from the radial striations, or granular surface, of the tubular area. Corallites with very closely adjoining tabulae, which are generally decidedly vesicular, but in places they are flat. In longitudinal sections there are from two to five tubules between neighboring corallites; the tabulae are convex, generally giving the inter-corallite space a decided vesicular structure. "The general vesicular condition of the tabulae in both the tubules and corallites distinguishes P. lambii." Remarks. — The above description agrees well with the external and internal features of the several Field Museum specimens. It seems desirable, however, to add here a few more characters not mentioned in the original diagnosis. The under surface of the corallum of this species is commonly covered by a concentrically wrinkled epitheca. The corallites are circular, with slightly raised margins. The radial striations or costae are twenty in number. They are not in direct continuation with the septa, and could not very well be, if the 1 Inasmuch as the species lambii was proposed by Schuchert in honor of L. M. Lambe, the correct designa- tion, as has been already pointed out by Teichert (1937, p. 54) should preferably be lambei. 3$ «$sw& j8R&&°^ Fig. 36. Plasmopora lambei Schuchert. F.M. No. P28828. a, Upper surface of a corallum; natural size, b, Enlarged corallites. c, Transverse section; x 3%. d, e, Longi- tudinal sections; X 3% and 4J^, respectively. /, Injured corallite, enlarged. The holotype of this species (U.S.N. M. No. 28140) is in the United States National Museum. 71 72 ORDOVICIAN FOSSILS OF BAFFIN LAND number of septa in each corallite is only twelve, as previously believed. It has, however, not been possible to determine the number of the septa, which presumably are represented by only a slight, wedge-shaped thickening of the walls of the corallites. The costae apparently project over the corallite openings, thus obscuring the outline of the septa and impeding clear observation. An important distinguishing feature of this species is the absence of polygonal divisions in the inter-corallite fields. This absence is the result of the union of the costae at an angle with the corresponding ones of the adjacent corallites without bifurcating or joining with additional transverse ridges between jux- taposed corallites. Both complete and incomplete tabulae occur. They are straight, convex, or irregularly curved. The tabulae of the tubules are similar but they are much more varied in shape, some of them being mere vertical zigzag lines. As may be seen from the longitudinal sections (fig. 36, d, e), the growth of the corallites apparently has been arrested periodically, during which times there seems to have been an excessive gemmation of the tubules. Some speci- mens of this species display on their surface a few conspicuously larger and more elevated corallites (fig. 36, /) having a greater number of costae. The exact nature of these corallites is not known, but they may have resulted from injury and subsequent repair of the normal corallites. Collectors. — John Jaynes, Ralph Robinson, and Sharat K. Roy. Plasmopora pattersoni Roy, sp. nov. Plasmopora lambei Troedsson, Medd. om Gr^nland, 72, pp. 118-120, 1928 (in part; probably pi. 31, fig. la, b, pi. 32, fig. 2, pi. 33, fig. la, b); Teichert, Rept. Fifth Thule Exped., 1921-24, Gyldendalske Boghandel, Nord. Forlag, 1, pp. 53-54, pi. 4, fig. 13, pi. 5, figs. 1, 2, 1937. Diagnosis. — This species is closely allied to the preceding species, Plasmopora lambei Schuchert, but the differences between the two seem definite and sufficient to warrant their separation. These differences are: P. lambei Schuchert P. pattersoni Roy, sp. nov. Corallum small; depressed hemispherical Corallum large; usually conical Corallites average 1.25 mm. in diameter Corallites average 2.25 mm. in diameter Costae twenty in number Costae twenty-four in number Inter-corallite fields irregular Inter-corallite fields polygonal Tabulae of corallites about twenty in 6 mm. Tabulae of corallites about thirty in 6 mm. Remarks. — The features seen in figures of "P. lambei" given by Troedsson (1928, pi. 31, fig. la, b, pi. 32, fig. 2, pi. 33, fig. la, b) and Teichert (1937, pi. 4, fig. 13, pi. 5, figs. 1, 2) correspond to those of P. pattersoni. There is little doubt that these representatives of "P. lambei" and the present species are conspecific. The specific name is in honor of my colleague, Mr. Bryan Patterson. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collectors. — John Jaynes, Ralph Robinson, and Sharat K. Roy. HoMype.—FM. No. P28829. Fig. 37. Phsmopora pattersoni Roy, sp. nov. F.M. No. P28829. o, View of upper surface of a corallum; natural size, b, Enlarged corallites. c, Transverse section; X 4. d, e, Longitudinal sections; X 4. 73 74 ORDOVICIAN FOSSILS OF BAFFIN LAND Order Tabulata Family Favositidae Edwards and Haime Genus Calapoecia Billings This genus has been ably revised and redescribed recently by Cox (1936). He regards this coral as a somewhat aberrant Tabulate, "characterized by the presence of a very open stereozone bounding its corallite, and twenty short, wedge-shaped septa rising periodically from the septal ridges, which alone make the corallite 'wall.' " He further finds that there is but one species belonging to this genus, viz., Calapoecia canadensis Billings, from which arise three varieties, C. canadensis var. ungava (Cox), C. canadensis var. anticostiensis Billings, and C. canadensis var. anticostiensis f. arctica (Troedsson). Calapoecia canadensis var. anticostiensis Billings Calapoecia canadensis var. anticostiensis Billings. For a complete bibliography and synonyms see Ian Cox, Bull. Nat. Mus. Canada, 80, Geol. Ser. No. 53, p. 12, pi. 1, fig. 6, pi. 3, figs, la-c, 3d, 5a-c, 6, 7, 1936. Description 1 (Cox, 1936, pp. 13-14). — "Major portion of a large mass, sliced transversely and polished. The surface shows radiating, circular corallites typically distant, a few in contact, with maximum diameter of 2.5 mm. The wall of each corallite is raised in a narrow rim from which twenty costae are distinctly seen to radiate, at a lower level, into the inter-corallite area. This area is depressed, but in some places rises to a subdued straight ridge between juxtaposed corallites; consequently the surface appears to be made up of poly- gonal units which contain a single corallite and its 'costae.' It must be said at once, however, that no trace of this ridge is to be observed in the internal structure. "In thin sections each corallite is seen to be bounded by an open mesh- work made up of septal ridges, which are produced into short, wedge-like spines at regular intervals (about 8 spines in 5 mm.) and fused to their neighbors at these levels. A section taken at such an horizon of fusion will show a circular corallite with a continuous wall made up of septa, which are in contact for about two-thirds of their length and then taper fairly abruptly inward to an obtuse point. But each septal spine is continued outward and slightly downward beyond the corallite boundary into the coenenchyme as a 'costa.' When their bases are not seen in the section (it will be remembered that they incline slightly downward) these 'costae' will appear as rods or spindles of about 0.75 mm. in length, lying on a circle of greater diameter than that of the corallite and separated from their neighbors by more or less wide pores. But sections at a level slightly higher than this will show septa passing continuously out into 'costae.' This is most commonly seen within the zone of septal fusion so that the corallite showing this feature probably will have a solid 'wall.' But some pores may be cut at such a level. This variation in the appearance of thin section 1 Based on Billings' holotype of "C. anticostiensis," G.S.C. No. 2267 (C. canadensis var. anticostiensis Billings). ****** Fig. 38. Calapoecia canadensis var. anticostiensis Billings. F.M. No. P28830. a, Corallum from above; natural size, b, Transverse section; X 3%. c, d, Longitudinal sec- tions; X3M. 75 76 ORDOVICIAN FOSSILS OF BAFFIN LAND is tersely shown in Lambe's diagrammatic figure, Plate I, figure 6a (1899) [Contr. Canad. Paleont., Geol. Surv. Canada, 4, pt. I], which, however, is not elucidated in his text. But his reference of this figure to his figure 6, which is too generalized, is misleading. "The mural pores, which lie on vertical and horizontal rows, are circular and probably have a diameter of no less than 0.25 mm. But the dilation of the septal spines and, to a less extent, of 'costae,' toward their bases, where they are fused to their neighbors, gives a funnel-like entrance to these pores. On account of the septal spines being arranged on horizontal and vertical rows, these 'funnels' have a rounded-quadrangular section at their widest part, but assume an oval, then circular, section as they lead into a pore. This, of course, happens within a very short distance, but it is important because certain authors have attached considerable weight to the shape of the pores in Calapoecia. This they have studied from the weathered interiors of corallites. It can be seen from the above description that the apparent shape of the pore in these cases will depend on the depth of weathering, and although a pore may appear to be quadrangular at first sight, it becomes clear, when the matrix is carefully removed with a needle, that this is the shape of the funnel-like entrance and not of the pore itself, which is circular. The term 'funnel' has been used merely to facilitate the making of this rather important point; of course it is not a structure, but only the result of the distribution and habit of the septal elements. These remarks are also applicable to longitudinal sections, where the pores will show a shape depending entirely on where the cut is made. "The tabulae are both complete and incomplete. A central count gives ten to twelve in 5 mm. They may pass through pores into the coenenchyme, but are typically bent upward at the periphery of the corallite, crossing the face of a pore and joining one septal spine to that above it. These upturned tabulae may give the false appearance of a wall in a transverse section cut through a region of pores. "The coenenchyme is well developed and consists primarily of horizontal elements which correspond fairly well with the number of tabulae in adjoining corallites and may commonly be continuous with these. Here and there curved plates run from one horizontal diaphragm to the next in a way exactly like the upturning of the tabulae at the periphery of the corallites. The 'costae' run into the coenenchyme and subdivide it vertically. The coenenchyme varies from regular and simple to a rather untidy arrangement within the single corallum." Remarks. — The above description gives a complete picture of the specimens at hand. The surface of the Field Museum specimens, however, is worn, result- ing in the smoothing down of the rim-like raised walls of the corallites to a con- siderable extent, thus making the radiating costae invisible except in thin sections. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collectors. — John Jaynes, Ralph Robinson, and Sharat K. Roy. DESCRIPTION OF FOSSILS 77 Family Halisitidae Edwards and Haime Genus Halysites Fischer de Waldheim Despite important contributions made by a number of investigators on Halysites, the difficulty of distinguishing species among individuals of that genus, or of segregating varieties under described species, has not been appreciably lessened. The difficulty seems to rest mainly on the astonishing variations, both in external and internal structures, that this coral presents to the investigator. Even in the same individual, the manner of growth of the corallites, their shape and size, the meshes of their reticulations, the spacing of the tabulae, and the character of the septal spines, if any, commonly are not the same. In fact, by examining thin sections from different portions of a single corallum it is not unusual to find greater variations among them than have been reported to exist between individuals that have been given specific or varietal rank. Those familiar with the mode of skeletal growth and colony formation of modern corals realize that a temporary change in the physical or chemical conditions surrounding the corals may easily result in a change in their normal structural growth. The observed variations in specimens of Halysites indicate that similar changes commonly occurred in the past. The age of the corals is another important factor in variations. Many individuals commonly show unusual conditions in their oldest cells which, if observed by themselves, may be mistaken for essential specific characters. Unfortunately, however, these differences, obviously results of environment and age, have not been taken into consideration by some authors who have used such criteria for specific differentia- tion. As a result, not a few species have been placed on record that are of very doubtful validity. Troedsson (1928, p. 130) has given a tentative table of classification in which he takes into consideration four pairs of features: (1) Presence or absence of tubuli; (2) presence or absence of septal spines; (3) small- or large-sized corallites; and (4) regular or irregular meshes. He believes that the application of these features or their combinations will be useful as one method of classification. Perhaps Troedsson's selection of diagnostic features would have been more com- plete if he had included among them a fifth pair, namely, whether or not the tabulae are closely or widely spaced. Nevertheless, his proposed criteria seem to offer greater possibilities for specific separation than have been hitherto recognized. Their application, however, will be of necessity limited, for the presence or absence of a pair or pairs of the above-mentioned determinative features may be observed in the same individual. Halysites agglomeratiformis Whitfield Halysites agglomeratiformis Whitfield, Bull. Amer. Mus. Nat. Hist., 13, p. 20, pi. 2, figs. 1, 2, 1900; Troedsson, Medd. om Gr0nland, 72, p. 133, pi. 46, fig. la-d, 1928. Description.— Corallum massive, corallites radiating from the center of the base. Meshes of reticulations small, elongated, and irregular. Corallites more barrel-shaped than rectangular, being much narrower at the end than at the wm r s Fig. 39. Halysiles agglomeratiformis Whitfield. F.M. No. P28831. o, Corallum; natural size, b, Cross section; X 4. c, Longitudinal section; X 4. 78 DESCRIPTION" OF FOSSILS 79 center; walls relatively thick; longer diameter of corallites about 2 mm., trans- verse diameter about 1 mm. Tabulae complete, straight or more commonly concave, averaging about eighteen in a space of 10 mm. Intercorallite tubuli and septal spines not observed. Remarks. — Halysites agglomeratiformis was first described by Whitfield (1900, p. 20). The holotype of that species together with three other species (Receptaculites pearyi, Calapoecia borealis and Heleolites perelegans) was collected from Cape Harrison, Princess Marie Bay, Ellesmere Land. Whitfield believed the horizon to be "the same as that of the New York Niagara or Clinton Group." The associated fauna, however, indicates that the horizon is late Ordovician rather than Niagaran. Whitfield's description of H. agglomeratijormis is too brief and his illustrations too indistinct for satisfactory comparison. I have, therefore, based the identification of the present species on Troedsson's descrip- tion and illustrations. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Halysites cf. H. gracilis (Hall) Halysites gracilis Troedsson, Medd. om Gr0nland, 72, pp. 131-132, pi. 40, figs. 2, 3a, b, 1928; Hussey, Contr. Mus. Paleont., Univ. Mich., 3, No. 3, p. 71, pi. 1, fig. 4, 1928; Teichert, Rept. Fifth Thule Exped., 1921-24, Gyldendalske Boghandel, Nord. Forlag, 1, pp. 55-56, pi. 7, figs. 3, 6, 1937 (for earlier references to literature and synonyms, see Bassler, Bull. U. S. Nat. Mus., 1, p. 586, 1915). This form is represented by only a small fragment of a corallum. Description. — Corallum massive (inferred). Meshes of reticulations large, irregular, a few polygonal. Corallites large, rectangular (slightly wider at the Fig. 40. Halysites cf. H. gracilis (Hall). F.M. No. P28832. a, Transverse section; approximately X 5. b, Longitudinal section; X 4. 80 ORDOVICIAN FOSSILS OF BAFFIN LAND center), with thick walls (0.5 mm.), average diameter of corallites 2.8 mm., transverse diameter 2 mm. Tabulae complete, averaging about nine in a distance of 8 mm., mostly straight, some inclined, a few concave. Septal spines very short, observed only in a few corallites. Intercorallite tubuli wanting. Remarks.— This form has been referred to H. gracilis (Hall) rather than to H. robustus Wilson, which it more closely resembles, inasmuch as it is not certain whether H. robustus is a distinct species or one of the many variable forms of H. gracilis. Less quadrangular corallites, thicker walls, and heavier tabulae, which have been considered as distinguishing H. robustus from H. gracilis, have also been observed in the latter. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — John Jaynes. Phylum ECHINODERMATA Subphylum Pelmatozoa Leuckart Class Cystoidea Leopold von Buck Order Rhombifera Zittel Family Callocystidae Bernard Subfamily Callocystinae Jaekel Genus Cheirocrinus Eichwald Cheirocrinus sp. Remarks. — The specimen is referable to the genus Cheirocrinus but it is too fragmentary for further consideration. Hitherto, in North America, no species of Cheirocrinus has been reported above the Trenton. The genus, however, occurs in the Richmond of Greenland, and, in Europe, in the Caradocian (probably equivalent to the Richmond) of Gir- van district. Horizon and locality. — Richmond. Silliman's Fossil Fig. 41. Cheiro- Mount, Frobisher Bay, Baffin Land. - crinus sp. F.M. 77 __ No. P28834. A Collector. — Sharat K. Roy. fragment of a plate; X 5. Class Crinoidea Miller Crinoids, with the exception of the plates of Carabocrinus mentioned here below, are represented by a number of stems of different kinds. These stems are found in rocks that have been considerably weathered. The stems are predominantly circular in outline although a few with pentagonal outlines have been observed. Inasmuch as they can serve no useful purpose here, their inclusion seems unnecessary. DESCRIPTION OF FOSSILS 81 Order Indunata Wachsmuth and Springer Suborder Fistulata Wachsmuth and Springer Family Cyathocrinidae Roemer Subfamily Carabocrininae Genus Carabocrinus Billings Carabocrinus sp. Remarks. — Members of this genus have been reported from the Chazy to the Richmond in North America. The genus also has been reported from the Richmond of Greenland. In Europe one species, Carabocrinus esthonus Jaekel, has been described from Wassalem (probably Lower Utica) of Esthonia. Horizon and locality. — Richmond. Silliman's Fossil Fig. 42. Carabo- Mount, Frobisher Bay, Baffin Land. No nW P28 P 833 F ' ] A Collector.— Sharat K. Roy. calyx plate; X 7. Phylum MOLLUSCOIDEA Class Bryozoa Ehrenberg Bryozoans are represented in this collection by five genera embracing six species. Of these, two forms, Prasopora sp. and Batostoma sp. are not illustrated here. Both were weathered, small fragments consisting of a few zooecia and were used up in the process of preparing them for identification. Besides the six species mentioned above, Dr. R. S. Bassler, while making a second study of a previous collection made at Silliman's Fossil Mount and described by Schuchert (1900), found six additional species, of which he identified two, Nematopora oralis Ulrich and Pachydictya pumila Ulrich (Bassler, 1911, pp. 35-36). Order Trepostomata Ulrich Suborder Amalgamata Ulrich and Bassler Family Monticuliporidae Nicholson Genus Atactoporella Ulrich Atactoporella cf. A. schucherti Ulrich Atactoporella schucherti Ulrich. See Bassler, Bull. U. S. Nat. Mus., 1, p. 87, 1915, for references to literature and synonyms. Remarks. — This species is represented by a small fragment of a zoarium. It is an incrusting form with petaloid to angular zooecia, numerous mesopores and small acanthopores indenting the zooecia. Its tangential section agrees well with the description of Atactoporella schucherti Ulrich from the Richmond of Ohio and Indiana but due to insufficient material it has not been possible to make a longitudinal section for comparison. 82 ORDOVICIAN FOSSILS OF BAFFIN LAND Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Fig. 43. Atactoporella cf. A. schucherti Ulrich. F.M. No. P28835. A small, naturally weathered fragment, showing zooecia, mesopores, and acanthopores; X 20. Collector. — Sharat K. Roy. Family Constellariidae Ulrich Genus Dianulites Eichwald Dianulites sp. Cf. Dianulites pelropolitanus Dybowski. See Bassler, Bull. U. S. Nat. Mus., 1, pp. 405- 406, 1915, for references to literature and synonyms. Description. — Zoarium massive, almost always hemispheric, with an epithe- cated base varying from 20 to 40 mm. in width. Celluliferous side usually uneven Fig. 44. Dianulites sp. F.M. No. P28836. a, Surface view; natural size, b, Polished vertical section; natural size, c, Tangential section; X 6. d, Vertical section; X 6. but shows no especial structural arrangement. Zooecia thin-walled, hexagonal, polygonal, or rounded, averaging twelve in 5 mm. Diaphragms present but their distribution cannot be ascertained as most of the tubes are filled with sedi- ments. Mesopores few. Acanthopores not observed. Remarks. — This form resembles Dianulites petropolitanus Dybowski from the middle Ordovician of North America and Esthonia, but the unsatisfactory nature of the preservation of the zooecial tubes, as mentioned above, does not allow clearer observation for certain specific identification. DESCRIPTION OF FOSSILS 83 Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collectors. — John Jaynes and Sharat K. Roy. Family Batostomellidae Ulrich Genus Eridotrypa Ulrich Eridotrypa bassleri Roy, sp. nov. Cf. Eridotrypa simulatrix (Ulrich). See Bassler, Bull. U. S. Nat. Mus., 1, p. 496, 1915, for references to literature and synonyms. Description. — Zoarium of cylindrical to somewhat flattened ramose branches. Zooecial apertures variable, oval, oblique or irregular, about seven in 3 mm., measuring longitudinally. Walls thick, highest posteriorly, sloping gradually Fig. 45. Eridotrypa bassleri Roy, sp. nov. F.M. No. P28837. o, A portion of a zoa- rium; natural size, b, Part of the same; enlarged, c, Longitudinal section; X 4. down into the apertures. Diaphragms few on the axial region but fairly numer- ous on the peripheral zone. Mesopores sparsely scattered. Acanthopores absent. Diagnosis. — In general appearance this species is suggestive of Eridotrypa simulatrix (Ulrich), from the Richmond. There are, however, certain apparent differences between the two which will serve to distinguish them readily from each other. The present species is a larger form with a less smooth surface, less regularly oval zooecia, and fewer diaphragms on the axial region. Remarks. — The specific name is in honor of Dr. R. S. Bassler, of the United States National Museum. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Holotype.— F.M. No. P28837. Eridotrypa cf. E. aedalis minor (Ulrich) Cf. Eridotrypa aedalis minor (Ulrich). See Bassler, Bull. U. S. Nat. Mus., 1, p. 495, 1915, for references to literature and synonyms. Description. — Zoarium of slender, cylindrical, ramose branches averaging 2 mm. in diameter. Zooecial apertures oblique and conspicuously drawn out anteriorly. Walls thick, highest posteriorly, sloping into the apertures. Inter- spaces between zooecia canaliculate, resembling channeled interspaces charac- 84 ORDOVICIAN FOSSILS OF BAFFIN LAND teristic of the genus Bythopora. Diaphragms more numerous in the peripheral region than on the axial region. Mesopores few. Acanthopores not observed. Remarks. — This bryozoan is represented by a few presumably young speci- mens. Externally it does not quite appear like the species to which it has been Fig. 46. Eridotrypa d. E.aedalis minor (Ulrich). F.M. No. P28838. a, A fragmentary specimen; X 2. b, Enlargement of a portion of the same specimen. referred for comparison, but its internal structures are very similar. Ulrich and Bassler have examined this form. The latter writes: "We were able to study the fragmentary bryozoan together and we agree that it is an Eridotrypa described by him [Ulrich] as E. mutabilis var. minor, now known as aedalis minor as you will note in my Bulletin 92, where also you will note that it is a Lower Trenton species in this country and a Middle Ordovician one in Esthonia. Your photo- graph, if it is of the same branch, appears to represent something different, but possibly it is due to a worn condition of the species." Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Class Brachiopoda Dumeril The brachiopods are represented in the collection by fourteen genera embrac- ing twenty-five species or varieties. All these are articulate forms belonging to the orders Protremata and Telotremata. Of the Order Protremata there are eleven genera represented, namely, Plectorthis, Platystrophia, Skenidioides(?), Hesperorthis, Glyptorthis, Austi7iella, Dalmanella, Parastrophinella, Rafinesquina, Sowerbyella, and Strophomena, and of Telotremata, three, Rhynchotrema, Zygo- spira, and Cyclospira. Most of the specimens are fairly well preserved, but unfortunately the different species are represented by only a few specimens, commonly by a single one. Of the twenty-five species and varieties mentioned above, eighteen are new; one, Glyptorthis bellarugosa (Conrad), has already been described; and because of their fragmentary condition the remaining six can neither be referred definitely to any known species nor advantageously described as new. DESCRIPTION OF FOSSILS 85 Order Protremata Beecher Suborder Orthoidea Schuchert and Cooper Superfamily Orthacea Walcott and Schuchert Family Plectorthidae Schuchert and Cooper Subfamily Plectorthinae Schuchert Genus Plectorthis Hall and Clarke Plectorthis inaequiconvexa Roy, sp. nov. Description. — Transversely suboval or truncato-suboval; valves nearly equal; of medium size; wider than long, length of holotype 14.6 mm., width at the hinge line 15.6 mm., maximum width 19 mm., maximum convexity 7 mm. Ventral valve convex, the greatest elevation being at the umbo. Lateral slopes more abrupt than the frontal slope. Beak a little arched and projecting Fig. 47. Plectorthis inaequiconvexa Roy, sp. nov. a, b, c, Ventral, dorsal, and lateral views of holotype. U.S.N.M. No. 28151. d, Ventral view of a different individual. F.M. No. P28258. All X \y z . but not incurved. Cardinal area well defined, broadly triangular and moderately convex; extremities angular. Dorsal valve much less convex than the ventral. Its greatest elevation is also at the umbonal region. Lateral and frontal slopes less pronounced than those of the opposite valve. Surface marked by about twenty-six strong, coarse, and simple plications, and all crossed by concentric lines (posterior ones obsolete, apparently due to weathering of the shell). Diagnosis. — This species shows close kinship to Plectorthis plicatella (Hall) and P. plicatella trentonensis 1 Foerste, but differs from both in having the ventral valve much more convex than the dorsal. This is best seen in lateral view (fig. 47, c) in which it is almost identical with that of Hebertella borealis (Billings). Furthermore, in the arctic species, the interspaces between the radiating plica- tions, particularly at the front, are wider. The plications themselves are all simple. No increase by implantation has been observed. Remarks. — There are three other specimens of this species in the United States National Museum (U.S.N.M. No. 28151). All were identified as Orthis (Hebertella) borealis (Schuchert, 1900, p. 157), perhaps because of their similarity to that species in lateral view. 1 The only difference between P. plicatella and its variety trentonensis seems to be that the latter is "more constant in the absence of secondary plications." (Foerste, 1910, p. 49.) 86 ORDOVICIAN FOSSILS OF BAFFIN LAND Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collectors. — The United States National Museum specimens were collected by J. N. Carpender and R. W. Porter; the Field Museum specimen was collected by Sharat K. Roy. Holotype.— U.S.N.M. No. 28151. Subfamily Platystrophiinae Schuchert Genus Platystrophia King Platystrophia magnisulcata Roy, sp. nov. Platystrophia biforata (not Schlotheim) Schuchert, Proc. U. S. Nat. Mus., 22, p. 158, 1900. Diagnosis. — This species closely resembles Platystrophia elegantula triplicata McEwan except that in the arctic species the hinge extremity is less acuminate, Fig. 48. Platystrophia magnisulcata Roy, sp. nov. U.S.N.M. No. 28154. Holotype. a, b, c, d, Ventral, dorsal, frontal, and lateral views, respectively; X 1M- the fold more pronounced, and the sulcus much deeper. Dorsal valve also flatter. These differences are so apparent that a new specific name seems desirable. Remarks. — Besides the holotype there is another specimen of this species in the United States National Museum. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collectors. — J. N. Carpender and A. H. White. Holotype.— U.S.N.M. No. 28154. Family Skenidiidae Kozlowski Genus Skenidioides Schuchert and Cooper Skenidioides(?) sp. Description. — Shell very small, length 2.3 mm., width 3 mm. Semi-elliptical in outline, the greatest width along the hinge line. Ventral valve subpyramidal, greatest elevation at the beak, then sloping almost uniformly at a steep angle to the lateral and front margins. Beak erect(?), cardinal area broadly triangular, apsacline. Delthyrium large and open. Dorsal valve depressed-convex, the sulcus originating at the beak and rapidly widening towards the front. DESCRIPTION OF FOSSILS 87 Surface ornamented with a few low, fiat plications which are undivided and characterized by being dotted with granules and marked by very fine lines. Remarks. — This form is represented by a single imperfect ^** ifefek specimen. The beak is partially broken, the cardinal area ■ somewhat obscured by calcareous incrustations, and the pli- '■^S^F cations, except on the lateral sides, are ill defined. It some- what resembles «S.(?) merope (Billings) and S. anthonense Sardeson, and although it can be distinguished from both Fig. 49. Skenidi- by its general shape and surface ornamentation, it is not oidesd) sp. F.M. sufficiently well preserved for comparison. sal view; x 6. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Family Orthidae Woodward Subfamily Hesperorthinae Schuchert and Cooper Genus Hesperorthis Schuchert and Cooper Hesperorthis interplicata Roy, sp. nov. Orthis tricenaria (not Conrad) Schuchert, Proc. U. S. Nat. Mus., 22, p. 156, 1900. Diagnosis. — In general, this species answers the description of Orthis tri- cenaria Conrad, except that its plications are not simple but implanted at the < ^SP W Fig. 50. Hesperorthis interplicata Roy, sp. nov. a, b, c, Ventral, dorsal, and cardinal views of holotype. U.S.N.M. No. 28149. d, Ventral valve of a different individual (A.M.N.H. specimen). All x l\i. beaks between the primary ones, and that it has more elevated median ridges on its ventral valve. These differences seem to be of sufficient importance to warrant a new name. Remarks. — There are two specimens of this species in the collection. Of these, one is fairly complete, the other damaged in several places. Both are young individuals but are nevertheless identical with two specimens (U.S.N.M. No. 28149) collected from Silliman's Fossil Mount and described by Schuchert as Orthis tricenaria Conrad. Another, larger specimen (fig. 50, d), also collected from Silliman's Fossil Mount and identified as 0. tricenaria Conrad, is now in the American Museum of Natural History. It was examined and found to be the same as the present species, Hesperorthis interplicata Roy. Since the specimens in the United States National Museum are better preserved, one of them has been designated as holotype. 88 ORDOVICIAN FOSSILS OF BAFFIN LAND Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collectors. — The specimens in the United States National Museum were col- lected by J. N. Carpender, the Field Museum ones by Sharat K. Roy, and the one in the American Museum of Natural History was collected by R.W. Porter. Holotype.—XJ.S.NM. No. 28149. Subfamily Glyptorthinae Schuchert and Cooper Genus Glyptorthis Foerste Glyptorthis bellarugosa (Conrad) SeeBassler, Bull. U. S. Nat. Mus., 2, p. 591, 1915, for references to literature and synonyms. Remarks.— A single representative of this species from Silliman's Fossil Mount is now in the American Museum of Natural History (A.M.N.H. No. 4800). It is almost identical with Hebertella (Glyptorthis) bellarugosa (Conrad Fig. 51. Glyptorthis bellarugosa (Conrad). A.M.N.H. No. 4800. a, b, c, d, Ventral, dorsal, cardinal, and lateral views, respectively; X lj^j. sp.) from Mineral Point, Wisconsin, and may be conspecific with it. The only difference observed between the two is that the sulcus of the dorsal valve in the arctic species is a little less pronounced at the front margin. This minor differ- ence is perhaps an individual variation rather than specific or varietal. Foerste (1914, p. 258) distinguishes Hebertella from Glyptorthis by the lam- ellate shell structure in the former genus. In the specimen considered here no lamellose growth lines have been observed. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector.— R. W. Porter. Family Dinorthidae Schuchert and Cooper Genus Austinella Foerste Austinella cooperi Roy, sp. nov. Orthis (Plectorthis) plicatella (not Winchell and Schuchert) Schuchert, Proc. U. S. Nat. Mus., 22, p. 156, 1900. Description. — Shell subquadrate; the largest one (holotype) of the ten specimens (one in Field Museum and nine in the United States National Museum) DESCRIPTION OF FOSSILS 89 is 18.5 mm. in length, 23.5 mm. in width, and 10 mm. in maximum convexity; the smallest one (paratype) is 9 mm. in length, 11.4 mm. in width, and 4.2 mm. in maximum convexity. Ventral valve strongly convex, the convexity decreasing gradually anteriorly to a shallow, almost imperceptible, wide sulcus. Beak small, slightly incurved; cardinal area arched, extremities not extended beyond the greatest width of the valve. Surface marked by strong, rounded ribs which increase by implantation in the umbonal regions, and all crossed by imbricating growth lines. The number | Fig. 52. Austinella cooperi Roy, sp. nov. a, b, c, d, Ventral, dorsal, cardinal, and lateral views, respectively, of holotype. U.S.N.M. No. 28150. e, /, Ventral and dorsal views of a different individual. F.M. No. P28261. All natural size. of radiating plications counted on the anterior margin of the youngest specimen is twenty -two ; of the largest specimen, the holotype, twenty -six. This number, however, varies with the individuals. The Field Museum specimen, which is smaller than the holotype, has twenty-eight plications. Dorsal valve slightly convex; median sulcus shallow, almost linear at the beak, but widening rapidly anteriorly to the front margin. In young specimens the sulcus is barely visible. Diagnosis. — Of the three described species of the genus Aiistinella, only A. scovillei Miller has some resemblance to the present species. The differences between the two, however, are apparent, and A. cooperi Roy, with its flatter form, fewer ribs, and less extended cardinal extremities, readily stands out as a distinct species. Remarks. — Since the largest specimen among nine of this species in the United States National Museum is the best-preserved one and superior to the Field Museum specimen, I have elected it as holotype. So far as is known, no species of the genus Austinella has previously been reported below the Richmond. The specific name is in honor of Dr. G. Arthur Cooper, of the United States National Museum. Horizon and locality.— Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. 90 ORDOVICIAN FOSSILS OF BAFFIN LAND Collectors.— The Field Museum specimen was collected by Sharat K. Roy and those in the United States National Museum were collected by J. N. Carpender. Holotype.— U.S.N.M. No. 28150. Austinella(P) subcircularis Roy, sp. nov. Plectorthis fissicosta (Hall) (labeled as P. fissicosta Meek, in the American Museum of Natural History). This species is represented by two fairly well-preserved specimens, 1 both in the American Museum of Natural History. Description. — Shell subcircular, the smaller one (holotype) 16.5 mm. in length, 20 mm. in width, and 7.5 mm. in maximum convexity; the larger one, | f Fig. 53. AuslineUa(!) subcircularis Roy, sp. nov. a, b, c, d, Ventral, dorsal, cardinal, and lateral views, respectively, of holotype. A.M.N.H. No. 4797. e, f, g, Ventral, dorsal, and lateral views of paratype. All natural size. which has a bulge at the umbonal region apparently due to mechanical pressure, 18 mm. in length, 21.5 mm. in width, and 9 mm. in maximum convexity. Ventral valve moderately convex, the convexity decreasing gradually anteriorly to a wide, shallow sulcus. Beak small, slightly turned outward. Cardinal area a little arched, extremities rounded. Surface marked by rounded ribs which increase by bifurcation and implantation on the anterior portion. The number of ribs (46 ±) is greater than observed in a specimen of equal size of A. cooperi Roy. The dorsal valve is equally or slightly more convex than the ventral. The character of the median sulcus is the same as that of the preceding species, A. cooperi. In the paratype the median sulcus is obscured by the tension produced by the umbonal bulge mentioned above. Diagnosis. — In general aspect the present species somewhat resembles Anstinella kankakensis (McChesney). This relationship, however, seems super- ficial when individual characters are compared. The arctic species is a smaller 1 Plaster casts of the holotype and paratype are in the Field Museum collection (F.M. Nos. P28262 and P28262A, respectively). DESCRIPTION OF FOSSILS 91 form having more rounded extremities and fewer plications. Its dorsal valve is also much more convex than that of A. kankakensis. Remarks. — The doubtful reference of this species to Austinella is due to the fact that no interior of the pedicle valve of the shell is available and hence the narrow, rectangular muscular area believed to be the most important diag- nostic character of this genus cannot be examined. The outward form and general appearance of this species, however, show stronger affinity to Austinella than to Plectorthis, Dinorthis, or Hebertella. Plectorthis fissicosta (Hall), with which this species was previously identified, is, as pointed out by Foerste (1910, p. 48), "characterized by the great prominence of the primary plications, causing them to appear widely separated, especially along the middle parts of the shell." This is not the case with A.(?) subcircularis Roy, in which the primary as well as the secondary (implanted) plications are more or less of equal prominence; at least, the difference is not conspicuous. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — R. W. Porter. Holotype — A.M.N.H. No. 4797. Superfamily Dalmanellacea Schuchert and Cooper Family Dalmanellidae Schuchert Genus Dalmanella Hall and Clarke Dalmanella diminutiva Roy, sp. nov. Description. — Shell subcircular, small, a nearly perfect specimen (holotype) being 8 mm. wide and 7.5 mm. long. Hinge line shorter than the greatest width of the valves. Ventral valve strongly convex, the surface sloping gradually and rather evenly in all directions. Median fold, consisting of four plications, scarcely discernible. Beak incurved, projecting over the cardinal area, which is high. % Fig. 54. Dalmanella diminutiva Roy, sp. nov. F.M. No. P28263. Holotype. a, b, c, Ventral, dorsal, and lateral views, respectively; X 3. Dorsal valve slightly convex, the greatest elevation posterior to the middle. A median sulcus, which commences very narrow at the beak, rapidly widens, and becomes undefined anteriorly. 92 ORDOVICIAN FOSSILS OF BAFFIN LAND Surface ornamented with about forty coarse, rounded radiating plications which bifurcate twice and increase by implantation between the beak and the free margins and all crossed by a few concentric lines of growth. Diagnosis. — The closest allied form to this species is Dalmanella cf. D. testudinaria (Dalman) of Troedsson (1928, pp. 82-83, pi. 20, figs. 2a-c, 3). Troedsson, however, does not describe his specimens in sufficient detail to insure satisfactory comparison. He concludes with the following remark (p. 83): "The American specimens [D. testudinaria] I have studied belong to the same general type, it is true, but they do not seem to be identical. The Cape Calhoun shells are dwarf forms. Their relations to the American 'Dalmanella testudinaria' cannot be determined without a closer study of the latter, which has not yet been performed." It is well known that in America D. testudinaria is not regarded as a definite species. It represents a variety of forms and as such any reference to it without mention of a particular form is of little comparative or diagnostic value. The present species also appears to be a dwarf form, but it differs from Troedsson's species in being more rotund and in having fewer, coarser, and less sharp plications. The ventral fold as well as the corresponding dorsal sulcus is also much less conspicuous in this species. Horizon and locality.— Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Holotype.—F.M. No. P28263. Dalmanella sillimani Roy, sp. nov. Description. — Shell subquadrangular to subcircular in outline, small, the largest one (holotype) of the five specimens in the present collection being 12.3 mm. long, 14 mm. wide. Hinge line shorter than the greatest width of the valves. ■ . ! I Fig. 55. Dalmanella sillimani Roy, sp. nov. F.M. No. P28264. Holotype. a, b, c, d, Ventral, dorsal, cardinal, and lateral views, respectively; X 1}4- Ventral valve strongly convex, the surface sloping in all directions at a moderately steep angle from the median ridge, which is highest posteriorly. Beak incurved, projecting slightly over the cardinal area, which is high and inclined towards the dorsal valve. Dorsal valve slightly convex. Beak nearly straight. Cardinal area not as high as that of the ventral valve. Median sulcus begins narrow at the beak, widening rapidly anteriorly. It is sharpest near the beak. DESCRIPTION OF FOSSILS 93 Surface marked by about 100 subrounded radiating plications, the result of repeated implantations and bifurcations of about fifteen principal striae which reach the apex. These plications are all crossed by faint concentric lines of growth. In younger specimens, which are usually rotund, the concentric lines are still less pronounced except near the margins. Diagnosis. — Of the related species compared with the present one the fol- lowing three, Dalmanella rogata (Sardeson) from the Black River and Trenton, Dalmanella corpulenta (Sardeson) from the Richmond, and Dalmanella ignota (Sardeson), also from the Richmond, show the closest affinity. It, however, dif- fers from these species in having a greater number of plications. Individually, it differs from D. rogata in having a more convex dorsal valve and less dispropor- tionate cardinal areas between the two valves; from D. corpulenta in being more quadrangular in outline; and from D. ignota in being less quadrangular and in having a less well-defined median ridge and a more convex dorsal valve. Unfor- tunately, there are no interiors of either valve of the present species at hand, and it has not, therefore, been possible to compare its internal characters with those of the three species just mentioned. The similarities of its exterior characters, however, are so striking that it would seem to have evolved from a not far distant ancestral form common to any or all three species here compared. Remarks. — Besides the holotype there are four paratypes (F.M. No. P28265) in the present collection. A number of specimens belonging to this species (iden- tified as D. testudinaria, U.S.N.M. No. 28148) are in the United States National Museum. All specimens of this species, so far seen, are extremely well preserved. The adhering clayey matrix of practically every specimen examined indicates that the specimens were weathered out of a clayey facies of the deposit. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Holotype.— -F.M. No. P28264. Dalmanella (?) sp. Description. — A partly preserved dorsal valve of a ^^ young species. The valve is convex and subtriangular. /Kk The sulcus, with three plications, the outside two being • Jm\V implanted, begins at the beak and gradually widens to the ™v^ front margins. Surface marked by bifurcating plications. Fig 56 Dalman- Remarks. — The above characters are the only ones that «Z/a(?)sp. F.M. No. can be seen in the specimen. Consequently, it cannot be P28266. Anincom- compared with any known species. The observable char- x 3 ' acters are also not sufficient to make the generic identifica- tion certain. Horizon and locality.— Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. 94 ORDOVICIAN FOSSILS OF BAFFIN LAND Suborder Pentameroidea Schuchert and Cooper Superfamily Pentameracea Schuchert Family Camarellidae Hall and Clarke Genus Parastrophinella Schuchert and Cooper Parastrophinella hemiplicata minor Roy, var. nov. Parastrophia hemiplicata (not Hall) Schuchert, Proc. U. S. Nat. Mus., 22, p. 158, 1900. Diagnosis. — The arctic examples of this variety of Parastrophinella hemi- plicata (Hall), of which there are five specimens in the United States National Fig. 57. Parastrophinella hemiplicata minor Roy, var. nov. U.S.N.M. No. 28156. Holo- type. a, b, c, Ventral, dorsal, and lateral views, respectively; X 2. Museum, differ from the typical P. hemiplicata from the Trenton of New York chiefly in being undersized and relatively less wide than long. These characters, however, are constant and seem sufficient to warrant a varietal name. Remarks. — The holotype and four paratypes (U.S.N.M. No. 28156) are in the United States National Museum. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector.— A. H. White. Holotype.— U.S.N.M. No. 28156. Superfamily Strophomenacea Schuchert Family Strophomenidae King Subfamily Rafinesquininae Schuchert Genus Rafinesquina Hall and Clarke Rafinesquina pronis Roy, sp. nov. Description. — Shell small, the holotype being 16 mm. long and 22.5 mm. wide. Semi-circular in outline. Hinge line a little shorter than the greatest width of the shell, lateral margins rounding to the front. Beak small, project- ing slightly over the cardinal area. Ventral valve slightly convex at the umbonal region, bending abruptly (laterally and anteriorly) almost at right angles at about two-thirds the distance from the beak. This abrupt flexure gives the valve a very strongly convex appearance on the anterior and lateral views. Surface marked by fine, low, rounded, radiating plications of nearly uniform size (a few at the front are DESCRIPTION OF FOSSILS 95 larger), increased towards the margins by bifurcation and implantation and crossed by very fine elevated concentric lines and wrinkles. The median radiat- ing rib is more conspicuous than any of the remainder, such as may be seen in R. declivis (James), R. squamula (James), and R. mucronata (Foerste). Fig. 58. Rafinesquina pronis Roy, sp. nov. a, Ventral valve of holotype. F.M. No. P28267. b, Interior of dorsal valve of paratype. F.M. No. P28268. Both X \\i- Dorsal valve conforms with the curvature of the ventral valve. The entire surface of the interior is dotted with irregularly placed granules of varying size. Diagnosis. — This species closely resembles R. declivis (James) in the abrupt downward flexure of its frontal and lateral margins and in the presence of a prominent median rib in the ventral valve. Otherwise, it is notably dis- similar and can be distinguished by its semi-circular outline and by the lack of prominence of every fourth, fifth, or sixth radiating plication. Remarks. — There are five specimens of this species in the Museum collec- tion, of which only two, a ventral valve (holotype) and an interior of a dorsal valve, apparently belonging to two different individuals, are well preserved. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collectors. — Sharat K. Roy and Ralph Robinson. Holotype.— F.M. No. P28267. Rafinesquina declivis subnutans Roy, var. nov. Description. — Shell small, wider than long, width 17 mm., length 15 mm. Suboval in outline. Hinge line straight, shorter than the width of the shell. Ventral valve convex, most elevated medially and at the umbonal region, the surface sloping almost to flatness (slightly reflected near the cardinal extremi- FlG. 59. Rafinesquina declivis subnutans Roy, var. nov. F.M. No. P28269. Holotype. a, b, Ventral and dorsal views, respectively; X l\i- 96 ORDOVICIAN FOSSILS OF BAFFIN LAND ties), thence deflecting abruptly at a short distance from the lateral and front margins. Beak scarcely produced over that of the opposite valve. Cardinal area narrow, linear. Radiating plications subangular, distinctly alternate, three to nine finer lines between the stronger ones increasing towards the margin by bifurcation and implantation and all crossed by fine concentric lines as well as by elevated wrinkles. Dorsal valve concave, corresponding to the curvature of the ventral valve. Surface marked by nearly equal radiating plications which, as in the opposite valve, are all crossed by fine, concentric lines and elevated wrinkles. Diagnosis. — This variety is more closely allied to Rafinesquina declivis (James) than is the preceding one, R. pronis Roy. It has, however, a larger flat area, and its downward flexure is not so abrupt. Furthermore, it does not have the prominent median rib on the ventral valve characteristic of R. declivis. These differences, although noticeable, are not significant enough for specific differentiation. A varietal distinction, however, seems desirable. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Holotype.—FM. No. P28269. Rafinesquina productiformis Roy, sp. nov. Description. — Shell small; outline suboval. Length and width, as far as preserved, 13.3 mm. and 16 mm., respectively. ^^^^^ Ventral valve strongly convex; umbo greatly incurved, giving it a productoid form. Hinge line a little inflected; *£££M \J cardinal area narrow,, linear. ^J Surface covered with irregular, wavy, rounded plica- tions and all crossed by concentric lines and wrinkles. Fig. 60. Rafines- Diagnosis. — Although this species is known only from a quina productiformis ventral valve it can be readily distinguished from all other No y 'P28270 V Holo- described species of the genus by its conspicuous incurved type. Ventral valve; umbonal region. x ^' Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Holotype.—FM. No. P28270. Rafinesquina sp. Description. — Shell small; wider than long, width 19 mm., length 16 mm. Subtrigonal in outline. Ventral valve strongly convex, the greatest convexity at the middle, the surface sloping rapidly in all directions. Hinge line straight, extending beyond DESCRIPTION OF FOSSILS 97 the width of the shell. Cardinal area narrow, linear; extremities slightly reflected. Beak projecting over the cardinal area. Surface obscured by calcareous incrustations, only a few stronger costae discernible at the middle. The interior is covered with papillae as evidenced by punctate structures on the exfoliated surface around the posterior region. Dorsal valve not observed. Remarks. — -In general appearance this shell approaches R. deltoidea (Conrad), especially the smaller forms, having regular convexity from the umbo to the anterior margin, but differs from it in the absence of rugose undulations on the surface of the disk characteristic of R. deltoidea. In the Fig. 61. Rafines- absence of the dorsal valve and because of the poor condition quina sp. F.M. No. f the ventral valve it has not been possible to compare this valve- x iy en rE specimen with any other known species. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Genus Sowerbyella (Sowerby) Sowerbyella sp. Plectambonites serecea(1) (Sowerby). See Bassler, Bull. U. S. Nat. Mus., 2, p. 997, 1915, for references to literature and synonyms. Remarks. — Several specimens of Sowerbyella are in the collection. They vary in size, the largest one being 11 mm. long and 18 mm. wide and the smallest measurable one 4.3 mm. long and 7.5 mm. wide. Whether all these specimens Fig. 62. Sowerbyella sp. F.M. No. P28272. a, b, c, Different individuals, d, Internal mold. All enlarged about \%. belong to one species cannot be definitely determined, although it appears almost certain that they represent more than one. Specific determination, however, has not been attempted, for such an attempt, until further revision of the many species and varieties described under this genus (0. T. Jones, 1928) is made, is likely to be uncertain and new names will only add to the confusion now existing. Horizon and locality.— Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collectors. — Sharat K. Roy, John Jaynes, and Ralph Robinson. 98 ORDOVICIAN FOSSILS OF BAFFIN LAND Subfamily Orthotetinae Waagen Genus Strophomena (Rafinesquina) Blainville Strophomena undulosa Roy, sp. nov. Description. — Shell of medium size, subtriangular in outline; length 17.5 mm., width 21 mm. Widest at hinge line; nasute in front. Dorsal valve convex, somewhat flat posterior to the middle, the remainder curving abruptly downward. Surface ornamented with alternating plications, the finer ones indistinct and undefined, and all crossed by concentric, undulating wrinkles. The wrinklings u % w Fig. 63. Strophomena undulosa Roy, sp. nov. a, Dorsal valve of holotype. F.M. No. P28273. b, Interior of ventral valve from Marshbrook, Shropshire, England. F.M. No. P10840. Both natural size. are most conspicuous on the posterior half of the valve; the remainder shows little regularity and in places is longitudinally wrinkled. Diagnosis. — This species appears almost identical with Strophomena fluctuosa Billings as figured by Troedsson (1928, pi. 22, fig. 13), but it is doubtful if his specimen is conspecific with S. fluctuosa. So far as they are visible in the illustrations, the differences between Troedsson's specimen and those figured by other authors (Bassler, 1915, 2, p. 1228) are too great to be attributed to the same species. The wrinkling in S. fluctuosa is more or less confined to the posterior flat portion, whereas in Troedsson's specimen, as well as in the present one, the wrinkling extends over the entire surface of the shell. It may be suggested that the difference in wrinklings in the arctic specimens is the result of unequal pressure, yet the fact that two specimens with identical wrinklings have been found in two widely separated localities is a strong argu- ment against such a conclusion. The wrinkling appears to be characteristic 1 rather than an abnormality. Of the described species, Strophomena trilobata (Owen) seems to show the closest relationships with the present species as well as with the one figured by Troedsson (1928, pi. 22, fig. 13). Both of these arctic forms, however, can be readily distinguished from S. trilobata by their charac- teristic wrinklings. 1 While this paper was in progress, a third specimen, F.M. No. P10840 (an interior of a ventral valve, fig. 63, 6), of similar form and having the same characteristic wrinklings, was found in a small collection of invertebrate fossils received by exchange from the University of Bristol, England, in 1910. The specimen was collected at Marshbrook, Shropshire, England, and incorrectly labeled as Lepiaena rhomboidalis (Wilckens). The Marshbrook specimen is very similar to the arctic form, differing only in the character of plications, which are almost uniform in the former but distinctly alternate in the latter. The difference in the character of plications, however, especially in this case, cannot be regarded as a criterion for specific differentiation as one is a dorsal and the other is a ventral valve, and, as such, the plications may not be similar, a feature not uncommonly seen in the opposite valves of certain other strophomenid shells. The Marshbrook specimen is of Caradocian time, which is approximately equivalent to Richmond of North America. DESCRIPTION OF FOSSILS 99 Remarks. — This species is represented by a single individual showing the exterior of a dorsal valve. Its distinctiveness and its striking similarity to Troedsson's "Strophomena fluctuosa," which he believes to represent the Rich- mond portion of the Cape Calhoun beds at Cape Calhoun, Greenland, suggest the possibility that it may become a good horizon marker. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Holotype.—FM. No. P28273. Strophomena sp. I Description. — Shell (dorsal valve) of medium size, length 16 mm., width 22 mm., widest at the hinge line. Sub-semielliptical in outline. Flat or slightly convex at the umbonal region, the convexity increasing evenly toward the central and anterior regions, from which the surface rounds off abruptly to the front and lateral margins. Hinge line straight; cardinal extremities acute, a little compressed and deflected. Beak small, indistinct. Surface ornamented with alternating plications, the stronger ones increasing by implantation near the front and lateral margins, the finer ones crowded, becoming totally undefined anterior to the umbonal region. Con- centric wrinkles faint and few. Remarks. — The diagnostic characters of this form, which is known only from a single dorsal valve, are insufficiently clear to permit its reference to any described species. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Fig. 64. Strophomena sp.I.F.M.No.P28274. Dorsal valve; X 1H- Strophomena sp. II Remarks. — This form is represented by a very poorly preserved ventral valve, which is strongly depressed at the umbonal region. The surface is marked by subrounded, not quite straight, alternating plications in groups of four or five. These are all crossed by numerous closely spaced concentric lines of growth, giving the surface a roughened appearance. In its present state of preservation it cannot be compared with any known species nor does it allow any adequate description. It has, however, the main characteristics of the genus Strophomena. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector.— Sharat K. Roy. Fig. 65. Stropho- mena sp. II. F. M. No.P28275. Ven- tral valve; X 1%. 100 ORDOVICIAN FOSSILS OF BAFFIN LAND Order Telotremata Beecher Superfamily Rhynchonellacea Schuchert Family Rhynchonellidae Gray Subfamily Rhynchotreminae Schuchert Genus Rhynchotrema Hall Rhynchotrema capax arcticum Roy, var. nov. Diagnosis. — This variety, represented by a young, well-preserved specimen, is closely allied to Rhynchotrema capax (Conrad), but only to those forms that are obese, gibbous, and have very strongly convex valves. It is well known that various specimens of Rhynchotrema, occurring in the Richmond, though obviously not conspecific, have been identified as Rhynchotrema capax merely Fig. 66. Rhynchotrema capax arcticum Roy, var. nov. F.M. No. P28277. Holotype. a, b, c, Ventral, dorsal, and lateral views, respectively; X l l A- because of a superficial resemblance to that species and more particularly because they were found in the Richmond. As such, a reference is here made to that form of R. capax to which the present variety is allied. The obese type originally described by Conrad (Jour. Acad. Nat. Sci. Phila., 8, p. 264, pi. 14, fig. 21, 1842) is abundant in the Whitewater in Indiana and Ohio and other localities. This arctic variety is also obese and gibbous and has strongly convex valves, but relative to its size and age these features are much more accentuated than in R. capax. Furthermore, the concentric lines of growth of the present variety are much more densely set. These growth lines, due to extensive exfoliation of the conchioline layer, can only be seen on a small area on the left antero-lateral side of the shell. The Cape Calhoun specimens described and figured by Troedsson (1928, p. 94, pi. 23, figs. 6-8) as R. capax probably belong to this variety. His speci- mens, like the Silliman's Fossil Mount one, are also gibbous and strongly convex, with the characteristic densely set growth lines. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Ralph Robinson. Holotype.— F.M. No. P28277. Rhynchotrema anticostiense breve Roy, var. nov. Description. — Shell very small, wider than long, length 7.5 mm., width 7.8 mm., subtriangular in outline. Ventral valve moderately convex. Median DESCRIPTION OF FOSSILS 101 sulcus with three plications begins shallow a little below the beak and rapidly deepens and widens anteriorly. Beak much elevated and slightly incurved. Cardinal area short but high. Dorsal valve convex, strongest at the umbonal region, sloping moderately in all directions. Beak pointed, slightly incurved, and situated well below the beak of the ventral valve. Median fold with four plications hardly recognizable posteriorly, but becoming deep and well defined anteriorly. Surface of both valves marked by 22 radiating plications which appear simple under an ordinary hand lens but under high power they show distinct . Fig. 79. a, Hormotoma sp. I. F.M. No. P28843. A fairly complete vertical section; X 2. b, Hormotoma sp. II. F.M. No. P28844. A fragmentary cast; natural size, c, d, Hormotoma sp. III. F.M. No. P28845. Both incomplete casts; natural size. DESCRIPTION OF FOSSILS 113 Hormotoma sp. I: Shell slender, very small; height 12 mm.; greatest diameter 3.5 mm.; apical angle about 15; composed of eight nearly uniformly rounded volutions. This form appears allied to Hormotoma gracilis cf. var. augustata (Hall) from the Black River. Hormotoma sp. II: The preserved portion of this form somewhat resembles the Trenton species Hormotoma salteri Ulrich. Hormotoma sp. Ill: This form is represented by two specimens but neither has retained any diagnostic character for specific identification. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Genus Eotomaria Ulrich and Scofield Eotomaria(?) robinsoni Roy, sp. nov. Clathrospira conica (in part) Schuchert, Proc. U. S. Nat. Mus., 22, p. 65, 1900. Description. — Shell conical, with moderately rounded base, short-spired, consisting of four and one-half complete whorls, probably one additional whorl * d ' f Fig. 80. EotomariaC!) robinsoni Roy, sp. nov. a, F.M. No. P28846; holotype. b, c, d, e, /, F.M. No. P28846A; paratypes. 1 All are internal casts showing different views; X 1 X A- and initial bulb missing. Greatest width and height about equal, varying between 7 and 9 mm. Apical angle 68 to 75. Upper surface of the last whorl sloping, nearly flat; that of the preceding whorls convex or gently rounded. Suture sharply impressed but shallow. Band not clearly defined, rather broad, concave, nearly vertical, situated above the periphery of the last whorl and immediately above the suture line on the preceding whorls. Umbilicus small, partly obscured by what appears to be a reflexed inner lip. Aperture rhomboidal in cross section, its margins and growth lines on the surface not preserved, thus making it impossible to determine whether the peripheral band is terminated by a notch or a slit. Diagnosis. — In the absence of essential diagnostic characters, the generic position of this species will necessarily remain uncertain. In general shape, in 1 A sixth paratype, F.M. No. P28846A, is in the collection but not figured here. 114 ORDOVICIAN FOSSILS OF BAFFIN LAND size, and in the contour of the surface of the slopes of its whorls it somewhat resembles Clathrospira conica Ulrich. It cannot, however, be referred to Cla- throspira, for that genus is characterized by having the band directly upon the periphery instead of upon its apical side, as in the case of the present species. Of the half dozen or so of the described species of Eotomaria, to which this arctic species has been doubtfully referred, only one species, E. canalifera Ulrich, has some general resemblance to Eotomaria{l) robinsoni Roy. E. canalifera, however, has a wider apical angle, is broader than high in lateral view, and the surface of the slopes of the whorls is decidedly concave. Dr. E. 0. Ulrich, who has examined these arctic gastropods, is inclined to regard them as related to certain Gotland shells, particularly to the two species described by Lindstrbm (1884, p. 150, pi. 14, figs. 18-21 and 35-43) as Trochus dali and T. wisbyensis. It is not certain whether the "band" in E. robinsoni is a true pleurotomarian band or whether its margins correspond to the longitudinal ridges seen in Lindstrbm's species. This is a point which cannot be decided without a specimen that has retained the growth lines or the mouth itself. Remarks. — The United States National Museum has six specimens (U.S.N.M. No. 28178) collected by J. N. Carpender, A. V. Shaw, and A. H. White from Silliman's Fossil Mount, Frobisher Bay, Baffin Land, and identified by Schuchert as Clathrospira conica. The smaller three of these six specimens are identical with E. robinsoni and represent the same species. The larger three are probably C. conica. The specific name is in honor of Mr. Ralph Robinson of Worcester, Massa- chusetts, who acted as mate of the Expedition Schooner Bowdoin and from whom was received invaluable aid in the field. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collectors. — Ralph Robinson, John Jaynes, and Sharat K. Roy. Holotype.—FM. No. P28846. Family Euomphalidae de Koninck NOTES ON INTERNAL CASTS OF MACLURINA AND MACLURITES The great majority of species belonging to the genera Maclurina and Maclu- rites have been founded on casts of the interior without the opercula. As such, the generic reference as well as the validity of a number of described species of these two genera remains questionable. Casts of the interior are extremely deceiving even to the most discerning eyes. The inner whorls in a cast appear higher than the last whorl, whereas in the original they might actually have been on a level with it or even lower, for the thickness of the test increases with each succeeding whorl and with age. Likewise, the suture in the cast may appear wider than its actual width, depending on the original thickness of the test. Further, inasmuch as the width of the suture may vary considerably in the same species, it cannot always be used as a dependable specific character. It is also apparent that a large number of the casts have been deformed by pressure DESCRIPTION OF FOSSILS 115 and by weathering, adding to the difficulties of satisfactory comparison with allied forms. These are important reasons why, when dealing with casts, more than ordinary caution must be exercised if confusion is to be eliminated and the species properly established. Experience shows that the size and nature of the umbilicus and the rate and manner of the growth of the whorls, all of which are best seen in vertical sections through the center, are the more easily recognized and reliable diagnostic criteria for differentiating low or flat spired casts such as these under discussion. In the collection there are forty-two casts representing the two genera Maclurites and Maclurina. Employing the above-mentioned procedure, it has been possible to separate the casts into three species. They appear closely related to Maclurina manitobensis (Whiteaves), Maclurina cuneata (Whitfield), and Maclu- rites crassus (Ulrich and Scofield), but it is not certain that they are conspecific. This is chiefly because it was found impractical to make satisfactory com- parisons with published figures. These casts are here regarded as sinistral, the flat side representing the spire and the umbilicated side the base. This orientation of the maclurid shells is not in accordance with the views held by Ulrich and Scofield. They believed that the shells were dextral and that the flat side was the base and the umbilicated side the spire on the basis that the "ridge which usually surrounds the umbilicus" corresponded to the "notch-keel of the Euomphalidae." (Ulrich and Scofield, 1897, p. 1038.) This is a possible interpretation but not entirely convincing. Living species of many gastropod families, e.g., the Trochidae, Turbinidae, Magilidae, and others, possess umbilical ridges on their bases, and the same might have been true of the shells under consideration. Genus Maclurina Ulrich and Scofield Maclurina manitobensis(?) (Whiteaves) Maclurina manitobensis (Whiteaves). Bassler, Bull. U. S. Nat. Mus., 92, p. 777 (with synonyms), 1915; Troedsson, Medd. om Gr0nland, 72, p. 21, pi. 9, fig. 3, pi. 7, fig. 2, 1928; Hussey, Contr. Mus. Paleont., Univ. Mich., 3, No. 3, p. 73, pi. 3, figs. 1, 5, pi. 4, fig. 4, 1928; Wilson, Trans. Roy. Soc. Canada, 25, ser. 3, sec. 4, p. 300, pi. 4, fig. 3, 1931; Teichert, Rept. Fifth Thule Exped., 1921-24, Gylden- dalske Boghandel, Nord. Forlag, 1, No. 5, p. 74, pi. 14, fig. 1, pi. 15, fig. 2, 1937. Remarks. — This well-preserved cast, having a maximum diameter of 116 mm., agrees in all essential particulars with Maclurina manitobensis (Whiteaves). The surface ornamentation (growth lines) is also similar, as indicated by a frag- ment of the test preserving the impression of exterior sculpture. The only notice- able difference is that its basal or umbilicated side is more prominent than observed in the published figures, the specimen at hand approaching in this character the shape of Maclurina cuneata (Whitfield). This widespread Trenton species has also been recorded from the Richmond of Putnam Highland, Baffin Land. Fig. 81. Maclurina manilobensis(l) (Whiteaves). F.M. No. P28847. umbilical, and lateral views, respectively; all natural size. 116 a, b, c, Upper, DESCRIPTION OF FOSSILS 117 Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector.— John Jaynes. Maclurina cuneata(?) (Whitfield) Maclurina cuneala (Whitfield). Bassler, Bull. U. S. Nat. Mus., 92, pp. 776-777 (with synonyms), 1915; Hussey, Contr. Mus. Paleont., Univ. Mich., 3, No. 3, p. 73, pi. 2, fig. 6, pi. 3, fig. 2, pi. 4, fig. 2, 1928. Original description (Whitfield, 1878, p. 75). — "Shell of medium size, attaining a diameter of three inches [76 mm.] and consisting of two or more volutions, which increase very rapidly in size; lower(?) [upper] side of the shell flat or very Fig. 82. Maclurina cuneata{1) (Whitfield). F.M. umbilical, and lateral views, respectively; all natural size. No. P28848. a, b, c, Upper, slightly concave between the suture-lines; the opposite side being depressed conical between the outer margin and the central depression, with a very slight convexity of the intermediate surface; outer margin of the volution sharply cuneate; central depression very small in the casts, leaving but little more space than would be occupied by the thickness of the shell. Transverse section of the volution triangular." Remarks. — Heretofore, so far as known, no specimen of this species has been found to exceed 76 mm. in diameter. In the present collection, however, con- sisting of twenty-one casts, the largest has a maximum diameter of 133 mm., the smallest 50 mm. All of these casts have the characteristic small umbilicus and regularly sloping under-sides, but variations exist, particularly with regard to the height of the spire, which may be either higher than the last whorl, lower, or on a level with it. Variations have also been observed in the angulation of the outer edges of the whorls, which in some casts are more obtusely angular than in others. These differences, however, are not constant enough to warrant spe- cific or varietal separation. Fig. 83. Maclurina cuneata{t) (Whitfield). F.M. No. P28848. a, Upper view, b, Vertical section, c, Umbilical view, d, Lateral view. All natural size. 118 DESCRIPTION OF FOSSILS 119 Maclurina cuneata (Whitfield) occurs in both the Trenton and the Richmond. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collectors. — Ralph Robinson, John Jaynes, and Sharat K. Roy. Genus Maclurites Lesueur The chief difference between the genera Maclurites and Maclurina, as pointed out by Ulrich and Scofield, is that in the latter the projections for the attachment of muscles on the inner side of the operculum are not present. It is obvious, therefore, that without the operculum generic identification of a maclurid is hardly possible unless it can be shown to be identical with a described species whose operculum is known. Maclurites crassus(?) (Ulrich and Scofield) Maclurites crassus (Ulrich and Scofield). Bassler, Bull. U. S. Nat. Mus., 92, p. 778 (with synonyms), 1915; Troedsson, Medd. om Gr0nland, 72, p. 19, pi. 3, fig. 4a-c, pi. 4, fig. 1, 1928; Hussey, Contr. Mus. Paleont., Univ. Mich., 3, No. 3, pi. 1, figs. 1, 2, pi. 4, fig. 1, 1928; Teichert, Rept. Fifth Thule Exped., 1921-24, Gyldendalske Boghandel, Nord. Forlag, 1, No. 5, p. 71, pi. 13, figs. 8, 9, 1937. Remarks. — These casts exhibit variations similar to those just recorded in Maclurina cuneata but vertical sections, showing the constancy of specific char- acters, clearly demonstrate that they represent but one species. Although Maclurites crassus (Ulrich and Scofield) is a common Trenton species, it has also been reported from the Richmond of Putnam Highland, Baffin Land. JIT Fig. 84. Maclurites crassusC!) (Ulrich and Scofield). F.M. No. P28849. a, b, c, Upper, umbilical, and lateral views, respectively; all natural size. Fig. 85. Maclurites crassus(l) (Ulrich and Scofield). F.M. No. P28849. a, Upper view, b, Vertical section, c, Umbilical view, d, Lateral view. All natural size. 120 DESCRIPTION OF FOSSILS 121 Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collectors. — Ralph Robinson, John Jaynes, and Sharat K. Roy. Maclurites(?) sp. Remarks. — This form is represented by a single vertical section formed by breaking and natural weathering. It consists of four and one-half whorls, which increase in size rather rapidly. The whorls are coiled nearly in the same plane and hence they are entirely exposed on the umbilical side. The nature of the coiling of the whorls distinguishes this form from any other in the present collection but in the absence of a complete specimen it has not been possible to compare this gastropod with any known species for specific determination. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Fig. 86. Maclu- rilesC!) sp. F.M. No. P28850. A vertical section; natural size. Family Trochonematidae Zittel Genus Trochonema Salter Trochonema cf. T. umbilicatum (Hall) Remarks. — The specimen representing this form agrees in all essential particulars with Trochonema umbilicatum and is perhaps conspecific with it. The only difference is that the shoulders of the whorls of the spire are more Fig. 87. Trochonema cf. T. umbilicatum (Hall). F.M. interior. Two views of the same individual; natural size. No. P28851. A cast of the rounded. In this it resembles Trochonema beachi Whitfield. The validity of that species, however, has been questioned by Ulrich and Scofield (1897, p. 1048). Furthermore, the rounding of the shoulders might have been caused by a calcareous deposit, as may be inferred from the difference in the color and texture of the cleaner surface of part of the peripheral regions of the whorls. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. 122 ORDOVICIAN FOSSILS OF BAFFIN LAND Trochonema(?) sp. Remarks. — This rapidly enlarging, subcorneal cast, composed of about seven volutions, of which the lower four can be seen, is so badly worn that it is impossible to identify it generically with certainty. It may be a Lophospira. The last whorl is large; shoulder slightly concave nearly to the suture; periphery, lower margin of which is obscure, moderately convex; basal portion rounded. ■ Fig. 88. Trochonema{1) sp. F.M. No. P28852. An imperfect cast of the interior; natural size. These are the only features worth mentioning here, and they do not supply definite diagnostic evidence. In general shape the present form is reminiscent of Trochonema rectangulare Raymond from the Chazy of Valcour Island, New York. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Genus Holopea (Hall) Holopea(?) sp. Description. — Shell very small, less than 10 mm. in diameter, with three or three and one-half rapidly enlarging volutions, coiling nearly in the same plane so that the inner whorls rise but little above the upper surface of the last. The surface of the , ,- specimen is encrusted, but, as far as can be ascertained, the upper side of the last whorl which is not complete is nearly flat; periphery convex, lower side abruptly rounded. Remarks. — The generic characters of this gastropod are not clear but they suggest the genus Holopea. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Fig. 89. Holo- pea(?) sp. F.M. No. P28853. A broken interior cast; X 3. DESCRIPTION OF FOSSILS 123 Subclass Euthyneura Spengel Order Opisthobranchia Milne-Edwards Suborder Pteropoda Cuvier Family Hyolithidae Nicholson Genus Hyolithes Eichwald Hyolithes crowelli Roy, sp. nov. Description. — Shell of medium size; length as far as preserved 13.5 mm.; maximum width 7.8 mm.; triangularly pyramidal; gradually tapering. Trans- Fig. 90. Hyolithes crowelli Roy, sp. nov. F.M. No. P28854. Holotype. a, An incomplete specimen, showing flattened side (ventral); X 2J^. b, Enlarged transverse growth lines, c, Cross section. verse section sub triangular. Convex side (dorsal) roof -shaped with angular crest; flattened side (ventral) gently convex; surface of the flattened side marked by very fine closely set transverse growth lines, which curve forward. These lines are not all of equal size. A few are stronger but their distribution shows no definite order. Diagnosis. — This species is unlike any hitherto described and can be imme- diately distinguished by its less elevated dorsal side (the angle at the crest being larger), and by its less rapid rate of tapering. Remarks. — The basal and the apical portions of the specimen are missing. It is also embedded, showing only the ventral side. The outline of the cross section where the apical portion is broken off is, however, sufficiently clear for the determination of the form of the dorsal side. The specific name is in honor of Captain J. T. Crowell, of Burnt Island, Maine. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Holotype.— -F.M. No. P28854. ■ • \^)r % Fig. 91. Endoceras baffinense Foerste. F.M. No. P28855. a, Dorsal view, b, Left lateral side, c, Ventral side (polished), showing siphuncle. All natural size. 124 DESCRIPTION OF FOSSILS 125 Class Cephalopoda Cephalopods are comparatively common at the head of Frobisher Bay, Baffin Land. In the present collection there are twenty-two specimens, repre- senting eleven genera and twenty species. The specimens are all casts of the interior, and unfortunately none is complete. In the majority of cases, however, a sufficient portion of the conch was preserved for dorso- ventral sectioning. It was, therefore, possible to examine the structure of the siphuncle in almost every speci- men which required such an examination for generic identification. For stratigraphic reasons, it may be of interest to mention that, of the cephalopods described here, only one, Westenoceras greggi Roy, sp. nov., was found in situ, 1 all the others having been collected from the loose material on the slopes of the outcrop. Subclass Tetrabranchiata Owen Order Nautiloidea Zittel Suborder Holochoanites Hyatt Family Endoceratidae Hyatt Genus Endoceras Hall Endoceras baffinense Foerste Cameroceras proteiforme Schuchert, Proc. U. S. Nat. Mus., 22, p. 169, 1900. Endoceras baffinense Foerste, Bull. Sci. Lab. Denison Univ., 23, pp. 14-15, pi. 7, fig. 5, 1928. Remarks. — A single internal cast representing this species was collected. It is like the holotype in general outline, length of the camerae, and structure of the siphuncle. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Endoceras sp. I This form is represented by two internal casts, both of which are parts of the ventral portions of the phragmocone. They are very similar to each other and may well be parts of the same individual. The smaller specimen is too fragmentary to warrant description; the larger one, consisting of twelve camerae, is described below. Description. — Length as preserved about 102 mm., width (lateral diameter) near adapical end 70 mm., near adoral end 77 mm. Camerae short, about ten camerae in a length equal to lateral diameter of conch. Sutures on ventral side broad, shallow lobes; their shape on lateral and dorsal portions not known. 1 Found partially embedded on the surface at the top of the hill. 126 ORDOVICIAN FOSSILS OF BAFFIN LAND Siphuncle large, ventral but not marginal; holochoanoidal. Near adapical end it measures about 21 mm. in diameter and is about 5 mm. from ventral wall; near adoral end these two measurements are 24 mm. and 8 mm., respectively. Remarks. — The most characteristic features of this form are its large siphuncle, short camerae, and sutures that form shallow, ventral lobes. It Fig. 92. Endoceras sp. I. F.M. No. P28856. a, Ventral view, b, Dorso-ventral section, showing siphuncle. Both natural size. may be related to Endoceras Julgur (Billings) from Anticosti Island but that species has still shorter camerae in proportion to the diameter of its conch. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Ralph Robinson. Endoceras sp. II This form is represented by a cast of the interior of six camerae of the phragmocone. Description. — As preserved, the specimen is 49 mm. in its greatest length, which is also the measurement of its dorso-ventral diameter at mid-length; lateral diameter 36 mm. Conch enlarges very gradually but so little of it is preserved that the exact rate of expansion cannot be determined. Due to DESCRIPTION OF FOSSILS 127 distortion during preservation, the dorsum of the specimen is much more convex than the venter and one of its lateral sides (right) is more rounded than the other, so that it is egg-shaped in cross section. Sutures curve apicad dorsally and ventrally and rise laterally to make broad, rounded saddles. Septa concave, joining the siphuncle with a sigmoid downward curvature. Fig. 93. Endoceras sp. II. F.M. No. P28857. a, Ventral view. c, Cross section, showing shape and position of siphuncle and endocone. section. All natural size. b, Lateral view. d, Dorso-ventral Siphuncle circular in cross section, situated ventrad of center of conch. Near adoral end of specimen it is about 3 mm. from ventral wall of conch and measures 15 mm. in diameter. Endocone located slightly ventrad of center of siphuncle; 33 mm. long (as preserved); rapidly tapering; longer dorso- ventrally than laterally, the two diameters being 7.5 mm. and 6 mm., respectively. Remarks. — This specimen is too badly preserved for specific comparison. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Endoceras sp. Ill Remarks. — This form is represented by a single natural longitudinal section of a part of a phragmocone consisting of seven camerae, all of which are badly Fig. 94. Endoceras sp. III. F.M. No. P28858. a, Dorsal view, b, Ventral view, showing siphuncle exposed by natural weathering. Both natural size. 128 •;a* Fig. 95. Endoceras sp. IV. F.M. No. P28859. a, Ventrolateral view. 6, Dorso- ventral section, showing parts of siphuncle. Both natural size. 129 130 ORDOVICIAN FOSSILS OF BAFFIN LAND worn or damaged. As preserved, it is over 90 mm. long, with a maximum diameter of 95 mm. Average length of camerae 9 mm. Septa concave, the concavity extending to the siphuncle without sigmoid downward curvature. Shape of sutures cannot be determined. Siphuncle large and elliptical or circular in cross section. At apicad end of the specimen, lateral diameter of siphuncle is about 35 mm. Two species to which this form may be related are Endoceras paliforme Miller from the Lander sandstone of Wyoming and E. manitobense Foerste from the Dog Head member of the Red River formation of Manitoba. The specimen under consideration, however, is so worn that it cannot be compared satisfactorily with either of these two species. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — John Jaynes. Endoceras sp. IV A single internal cast consisting of the left half of six camerae of the phragmocone represents this form. Description. — Length in its present state of preservation about 115 mm.; width near adapical end about 94 mm., near adoral end about 101 mm. Cross section circular or very broadly elliptical. Sutures slightly curved (mostly due to distortion), forming shallow, broadly rounded ventral lobes. Camerae long, averaging about 20 mm. Siphuncle poorly preserved but large, being close to 50 mm. in diameter near adoral end; located ventrad of center of conch (about 11 mm. from ventral wall); holochoanoidal in structure. Remarks. — The large camerae and particularly the very large siphuncle are the most characteristic features of this form. They seem to differentiate it readily from previously described species, but it is not sufficiently complete to serve as a type. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Ralph Robinson. Suborder Orthochoanites Hyatt Family Orthoceratidae M'Coy Genus Ephippiorthoceras Foerste Ephippiorthoceras Foerste, Contr. Mus. Geol., Univ. Mich., 2, No. 3, p. 86, 1924; Mem. Geol. Surv. Canada, 145, pp. 71-72, 1925; Contr. Mus. Paleont, Univ. Mich., 3, No. 3, p. 40, 1928. Genotype: Orthoceras formosum Billings, Geol. Surv. Canada, Rept. of Progress, p. 317, 1853-56 (published in 1857); Foerste, Mem. Geol. Surv. Canada, 145, p. 72, pi. 11, fig. 11, also text fig. 7, 1925. DESCRIPTION OF FOSSILS 131 Emended description (Foerste, 1928c, p. 40). — "Conchs orthoconic, with sutures of septa curving distinctly downward laterally, and with the segments of the siphuncle enlarging to vertically elliptical or spherical outlines, but not vertically depressed and disk-like, or nummuloidal." Ephippiorthoceras sp. I Remarks. — This form is represented by a single, somewhat distorted cast. It is cylindrical in shape, is about 67 mm. long and 42 mm. in diameter. In cross section it is (in its distorted condition) subcircular. The adapical end of the specimen is an impression of a septum. Otherwise, there are no traces of septa present, and, therefore, presumably only the living ii t». Fig. 96. Ephippiorthoceras sp. I. F.M. No. P28860. o, Ventral view, b, Lateral view, c, Outline of adapical end (impression of a septum), showing probable position of siphuncle. All natural size. chamber is represented. The septa appear to have formed broad, shallow, rounded lateral lobes and similar dorsal and ventral saddles. A structure on the adapical end of the specimen seems to represent the siphuncle. It is located ventrad of the center, is circular in form, and about 6 mm. in diameter (fig. 96, c). The adoral end of the specimen is slightly but distinctly constricted. Most probably this represents an apertural constriction, but the state of preservation of the fossil is such that it is difficult to confirm this conclusion. It can hardly be doubted that this specimen is a typical representative of Ephippiorthoceras, but because it is somewhat distorted and because the phragmocone is not preserved, it has not been possible to compare it with other described species of the genus for its specific affinity. Foerste described two species of Ephippiorthoceras (E. baffinense and E. compressum) from the same 132 ORDOVICIAN FOSSILS OF BAFFIN LAND locality at which the present specimen was collected, but neither of them appears to be similar. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Ephippiorthoceras sp. II Another small, weathered, and poorly preserved specimen having some of the characteristics of Ephippiorthoceras is in the present collection. Description. — Length 55 mm., representing nine camerae of phragmocone; circular or nearly so in cross section but the specimen is so worn that its shape cannot be definitely ascertained. Conch, so far as could be determined, increases gradually adorally. Fig. 97. Ephippiorthoceras sp. II. F.M. No. P28861. a, Ventral view, b, Section, showing siphuncle. Both natural size. Sutures slightly sinuous, forming broad, shallow, ventral lobes and similar lateral saddles. Camerae rather long, their average length being 6.5 mm. Siphuncle small, located midway between center and venter. At a break along a septum near mid-length of specimen, siphuncle about 2 mm. in diameter and about 3 mm. from venter. Segments slightly expanded within camerae; fusiform in shape. Septal necks short, slightly recurved, and about 0.5 mm. long near adoral end of specimen. Remarks. — The siphuncle of this specimen does not appear to be expanded within the camerae as much as is typical for Ephippiorthoceras. It is also located relatively close to the venter. The sutures, however, are characteristic of that genus. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. DESCRIPTION OF FOSSILS 133 Family Apsidoceratidae Hyatt Genus Charactoceras Foerste Charactoceras Foerste, Bull. Sci. Lab. Denison Univ., 20, pp. 234-235, 1924; 30, p. 83, 1935. Genotype: Trochoceras(?) baeri Meek and Worthen, Proc. Acad. Nat. Sci. Phila., 17, p. 263, 1865; Meek, Geol. Surv. Ohio, Paleont., 1, p. 157, pi. 13, fig. 9, 1873; Foerste, Bull. Sci. Lab. Denison Univ., 20, pp. 235-239, pi. 31, fig. 1, pi. 32, fig. la, b, pi. 33, fig. la, b, pi. 34, figs, la, b, 2, 1924; Troedsson, Medd. om Gr0n- land, 71, pp. 39-40, pi. 19, fig. 1, 1926. Emended description (Foerste, 1935, p. 83). — "Conch nautiloid, depressed dorso-ventrally, with a distinct dorsal impressed zone. The transverse striae on the surface of the shell indicate that the hyponomic sinus was broad and relatively deep but not abrupt. The sutures of the septa curve slightly down- ward laterally and rise higher ventrally than dorsally. The siphuncle is located on the ventral side of the conch but not near contact with the latter. The segments of the siphuncle enlarge but moderately within the camerae, being distinctly elongated lengthwise. There is no trace of transverse ribs." Charactoceras schucherti Foerste Eurystomites plicatus Schuchert, Proc. U. S. Nat. Mus., 22, p. 173, 1900. Charactoceras schucherti Foerste, Bull. Sci. Lab. Denison Univ., 23, pp. 61-62, pi. 9, fig. 2a-c, pi. 27, fig. 4a-d, 1928. Fig. 98. Charactoceras schucherti Foerste. F.M. No. P28862. An incomplete cast of the interior, a, Lateral view, b, Dorso-ventral view. Both natural size. 134 ORDOVICIAN FOSSILS OF BAFFIN LAND Remarks. — This species, based on an incomplete cast of the interior (U.S.N.M. No. 28123), has been as adequately described by Foerste (1928, pp. 61-62) as his specimen permitted. The Field Museum specimen is also an interior cast and, unfortunately, except for having a little more of the living chamber preserved, it is as incomplete as Foerste's; a study of it does not add materially to the original description. Its dorso-ventral section fails to show the siphuncle, but its general form and the character of the sutures are identical with and indistinguishable from those of the species to which it has been referred. Charactoceras plicatus (Whiteaves) (1897, pp. 225-227) from the Winnipeg limestone, which is probably of Richmond age, and C. rotundum Troedsson (1926, p. 40) from the Richmond portion of the Cape Calhoun series are the only two species to which the present one is closely related. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Suborder Cyrtochoanites Hyatt Family Actinoceratidae Saemann Genus Actinoceras Bronn Actinoceras sp. A small specimen represents the adapical portion of a species of Actinoceras. Description. — As preserved, 36 mm. long; subcircular in cross section, being more broadly rounded ventrally than dorsally; conch expanded orad moderately rapidly. r Fig. 99. Actinoceras sp. F.M. No. P28863. a, b, c, Ventral, dorsal, and lateral views, respectively, d, Dorso-ventral section, showing siphuncle. e, Cross section, showing position of siphuncle. All natural size. Sutures straight, directly transverse on dorsal half of conch but near center of lateral sides they curve apicad and form broadly rounded ventral saddles. Camerae relatively large; adoral four camerae average about 6 mm. in length. DESCRIPTION OF FOSSILS 135 Siphuncle large, segments globular, expanded within camerae (more strongly dorsally than ventrally). Near adoral end of specimen siphuncle located about 2 mm. from ventral wall of conch. Septal necks strongly recurved and a little more than 1 mm. long. Remarks. — Inasmuch as only the adapical portion of this specimen is pre- served, specific comparisons are not possible. It, however, seems to possess all essential diagnostic characters of the genus Actinoceras. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — John Jaynes. Genus Leurorthoceras Foerste Leurorthoceras Foerste, Bull. Sci. Lab. Denison Univ., 19, pp. 278-279, 1921; Contr. Mus. Paleont., Univ. Mich., 3, No. 3, p. 44, 1928. Genotype: Leurorthoceras hanseni Foerste, Bull. Sci. Lab. Denison Univ., 19, pp. 278- 282, 1921; Troedsson, Medd. om Gr0nland, 71, pp. 59-60, pi. 29, figs. 4, 5, 1926. Emended description (Foerste, 1928c, p. 44). — "Conch flattened along its ventral side, the sutures of the septa with broad, ventral lobes. The location of the siphuncle is distinctly ventral, but not in contact with the ventral wall of the conch. The septal necks are distinct and relatively long. The connecting rings enlarge within the camerae, and vary from vertically elliptical to approxi- mately globular in outline, but they are not enlarged sufficiently in a lateral direction to secure a flattened disk-like appearance, as in typical Actinoceras." Leurorthoceras (?) baffinense Foerste This species is represented by an internal cast of the ventral half of thirteen camerae of the phragmocone. Description. — Length as preserved about 220 mm., maximum width about 125 mm., not expanded appreciably adorally. Sutures form broadly rounded, shallow lobes on ventral side; their course on lateral and dorsal sides is not known. Length of camerae varies, but average about 17 mm. Siphuncle not preserved internally, as shown by a dorso-ventral section. Externally, on weathered surface, it appears to be ventral and large, having a diameter of more than 25 mm. near adapical end and composed of segments that are greatly expanded within the camerae. Remarks. — Both the holotype of this species and the specimen under consideration are very incomplete. Nevertheless, all of their characters that can be determined seem to coincide so closely that they are almost certainly conspecific. Leurorthoceras{1) baffinense is from the Richmond of Putnam Highland, Baffin Land. Fig. 100. Leurortkoceras (?) baffinense Foerste. F.M. No. P28864. Ventral side; natural size. 136 DESCRIPTION OF FOSSILS 137 Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Leurorthoceras(P) cf. L. baffinense Foerste Remarks. — The specimen representing this form is so fragmentary that it does not admit of satisfactory comparison with known species. Beyond the fact that the downward curvature of the sutures (lobes) of its ventral side is Fig. 101. Leurorthoceras{t) cf. L. baffinense Foerste. F.M. No. P28865. A fragment of the ventral side of the phragmocone; natural size. similar to that in L. baffinense Foerste, and that the length of the camerae in both are about the same, there are no other details preserved for comparison. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Genus Kochoceras Troedsson Kochoceras Troedsson, Medd. om Gr0nland, 71, p. 65, 1926; Foerste, Bull. Sci. Lab. Denison Univ., 30, p. 58, 1935. Genotype: Kochoceras cuneiforme Troedsson, Medd. om Gr0nland, 71, pp. 68-71, pi. 37, figs. 2-4, pi. 38, pi. 39, pi. 40, figs. 1-2, pi. 44, fig. 6, 1926; Foerste, Bull. Sci. Lab. Denison Univ., 30, p. 58, 1935; Teichert, Rept, Fifth Thule Exped., 1921-24, Gyldendalske Boghandel, Nord. Forlag, 1, No. 5, p. 96, pi. 19, fig. 7, 1937. 138 ORDOVICIAN FOSSILS OF BAFFIN LAND Original description.— "Br eviconic or rarely longiconic orthoceracones with flattened ventral side and actinoceroid siphuncle. The latter is large, almost filling up the apical portion of the conch, and is tightly pressed against the ventral side of the conch until flattening and confluence of the annulations." Revised description (Foerste, 1935, p. 58). — "Conchs closely similar to Actinoceras, but the ventral side is strongly flattened, the lateral sides rounding rapidly into the much more broadly rounded dorsal side of the conch. The siphuncle is depressed dorso-ventrally and is in flattened contact with the ventral wall of the conch. The contact areas on the connecting rings usually are broad and conspicuous, the septal necks being free from contact. Successive segments of the siphuncle usually diminish in diameter dorso-ventrally and even laterally." Kochoceras troedssoni Roy, sp. nov. This species is represented by a part of a phragmocone consisting of nine camerae, most of which are broken or otherwise damaged. Its interior is also filled with crystalline calcite. It has, therefore, not been possible to make a dorso-ventral section to examine the structure of the siphuncle as clearly as is desirable. Description. — Length as preserved 142 mm. Conch subelliptical in cross section, the ventral side being distinctly flattened and the dorsal side strongly convex, almost semi-circular. Apical end represents a septum which is subcorneal, its angle of inclination being much less on the ventral than on the dorsal side. At adoral end of this septum, lateral diameter of conch is about 51 mm. and dorso- ventral diameter about 37 mm., whereas near adoral end of specimen the esti- mated diameters are 104 mm. and 44 mm., respectively. Rate of lateral expansion is 24 mm. in a length of 55 mm. Siphuncle large, nummuloidal, as may be deduced from its segments, which are greatly expanded within the camerae. At apical end of the specimen the siphuncle is about 14 mm. in diameter, but near mid-length it attains a diameter of about 35 mm. within the camerae. Presumably segments of siphuncle are in contact with ventral wall of conch within the camerae, but not at their junction with the septa. Diagnosis. — Of the various species referred to this genus, only two, namely, Kochoceras cuneiforme Troedsson, from the Richmond of Cape Calhoun, Green- land, and K. sublentiforme Miller, from the Lander sandstone of Wyoming, may be mentioned here as related to the present species. The Greenland species, however, has a larger apertural angle, and the one from Wyoming has shorter camerae. The lobes of the sutures on the ventral side of the latter species are also distinctly deeper. Remarks. — When Troedsson established the genus Kochoceras (1926, pp. 65-66), he apparently mistook a septum for the adapical end of the conch. This becomes clear when one examines the form of the fifth septum from the apical end of the holotype of K. magnicameratum Miller (1932, pi. 22, fig. 2). Fig. 102. Kochoceras troedssoni Roy, sp. nov. F.M. No. P28866. Holotype. a, Dorsal side, b, c, Lateral sides, d, Ventral side. All natural size. 139 140 ORDOVICIAN FOSSILS OF BAFFIN LAND Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Holotype.—FM. No. P28866. Kochoceras sp. Remarks. — This fragment, consisting of only three segments of a siphuncle, almost certainly represents the genus Kochoceras, and perhaps it is conspecific with K. troedssoni Roy. Its poor state of preservation, however, does not permit more certain identification. Fig. 103. Kochoceras sp. F.M. No. P28867. Dorsal view of three segments of siphun- cle. Natural size. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Family Onoceratidae Hyatt Genus Westenoceras Foerste Westenoceras Foerste, Bull. Sci. Lab. Denison Univ., 20, pp. 253-254, 1924; Contr. Mus. Paleont., Univ. Mich., 3, No. 3, p. 48, 1928; Bull. Sci. Lab. Denison Univ., 30, p. 59, 1935. Genotype: Cyrtoceras manitobense Whiteaves, Trans. Roy. Soc. Canada, 7, sec. 4, p. 80, pi. 13, figs. 3-5, pi. 15, fig. 4, 1890; Foerste, Contr. Mus. Paleont., Univ. Mich., 3, No. 3, pp. 49-50, pi. 5, fig. 1, pi. 11, fig. 5, 1928. Emended description (Foerste, 1935, p. 59).— "Conchs curved lengthwise, with the ventral side convex, this convexity being accentuated at a hump 4 or 5 camerae beneath the base of the living chamber ventrally. A much smaller gibbosity is shown by the dorsal outline along the upper part of the phragmocone, a short distance beneath the living chamber; the lower part of the phragmo- cone and the upper part of the living chamber here tend to be faintly concave. The sutures of the septa curve downward laterally, the maximum depth of the resulting lobes being dorsal of the center of the conch. The ventral [saddles rise higher than the dorsal ones and are distinctly subangular. The siphuncle is near, but not in contact with the ventral wall of the conch. Its segments are barrel- DESCRIPTION OF FOSSILS 141 shaped, narrowing abruptly where near contact with the septa, with a narrow passage through the septa, their lateral sides being gently convex in vertical sections." Westenoceras greggi Roy, sp. nov. This species is represented by a fairly well-preserved cast of the interior, consisting of twenty-five camerae of the phragmocone and about 34 mm. of the liv- ing chamber. The specimen, however, is broken into two pieces and a portion of the left lateral side of the living chamber and at least the seventh and eighth camerae apicad of the junction of the living chamber and the phragmocone are missing. It is thus difficult to place these two broken and separated parts in their exact position, although there is a matrix contact. The description given here of the form of the individual (as if it were intact) is, therefore, subject to a slight amount of error. Description.— -Total length (of the two separated parts referred to above) at mid-line of right lateral side about 175 mm. Ventral side moderately convex in vertical outline, its maximum convexity being between the sixth and ninth camerae (unfortunately the missing ones); dorsal side slightly concave though apparently slightly convex near the junction of phragmocone and living chamber. Conch exogastrically curved; cross section of well-preserved portion of phrag- mocone subcircular. Dorso-ventral diameter of apical end of specimen 18 mm., of the fifteenth camera orad of apical camera 47 mm., an expansion of 29 mm. within a distance of 87 mm. Adapical 45 mm. of phragmocone and preserved portion of living chamber depressed laterally and weathered to such a degree that their original forms are more or less lost. Adoral end of living chamber subcircular (inferred), its dorso-ventral diameter at least 42 mm., the other diameter about 32 mm. (both measurements estimated). Surface of specimen marked by numerous low, broad, longitudinal ribs separated by narrow, shallow grooves. Sutures on lateral sides nearly perpendicular to long axis of conch, rising but slightly ventrally and dorsally to form broad, rounded saddles. Camerae increase in length anteriorly; length of apical one of specimen 4 mm. and the sixteenth one 7 mm. Septa concave but the concavity increases very gradually anteriorly. Concavity of a septum near mid-length measures about 8 mm. Siphuncle circular; situated close to ventral wall of conch. At apical camera of specimen it is hardly 2 mm. away from the wall; at mid-length the distance is about 9 mm. Its maximum diameters at these two points are 5 mm. and 13 mm., respectively. Segments greatly expanded within camerae and siphuncle is nummuloidal in structure. Septal necks strongly recurved. Apparently there were annular deposits inside the siphuncle on the septal necks, but the state of preservation of the internal structures of the specimen does not permit the precise nature of these deposits to be determined. Diagnosis. — This species is related to W. deckeri Foerste of the upper Viola of Oklahoma but it differs in having a smaller apical angle and longer camerae. Fig. 104. Westenoceras greggi Roy, sp. nov. F.M. No. P28868. Holotype. a, Lateral view, 6, Dorso-ventral vertical section of ninth, tenth, and eleventh camerae, showing siphuncle and annular deposits inside the siphuncle on the septal necks. Both natural size. 142 DESCRIPTION OF FOSSILS 143 The specific name is in honor of Major Clifford C. Gregg, Director of Field Museum of Natural History. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Holotype.—FM. No. P28868. Genus Winnipegoceras Foerste Winnipegoceras Foerste, Contr. Mus. Paleont., Univ. Mich., 3, No. 3, pp. 55-56, 1928; Bull. Sci. Lab. Denison Univ., 30, p. 38, 1935. Genotype: Cyrtoceras laticurvatum Whiteaves, Geol. Surv. Canada, Paleont. Fossils, 3, pt. 3, p. 224, text fig. 14, 1897; Foerste, Contr. Mus. Paleont., Univ. Mich., 3, No. 3, pp. 56-58, pi. 9, figs. 1, 2, 1928; Bull. Sci. Lab. Denison Univ., 30, pp. 38-39, pi. 4, fig. 2, 1935. Original description. — "Conch strongly curved in a lengthwise direction, with the ventral side convex and the dorsal side strongly concave, differing in this respect from Westenoceras, in which the lengthwise curvature is relatively small, the dorsal outline being slightly gibbous along the upper part of the phragmocone and the lower part of the living chamber. In Winnipegoceras the conch is humped along the upper part of its ventral outline at a point five or six camerae below the base of the living chamber, and this chamber is long and attenuated toward the aperture, as in the genus named. Although the vertical dorso-ventral section through the genotype passes directly through the center of the siphuncle for most of its length, the details of structure of this siphuncle still remain vague." Emended description (Foerste, 1935, p. 38). — "The holotype resembles the genus here called Neumatoceras in the enlargement of the conch to a point distinctly below the base of the living chamber, the remainder of the phragmocone and the lower part of the living chamber tapering thence upward. The conch of Winnipegoceras, however, attains a much larger size, curves more strongly lengthwise considering its size, and the living chamber is much longer." Winnipegoceras laticurvatum (Whiteaves) Cyrtoceras laticurvatum Whiteaves, Geol. Surv. Canada, Paleont. Fossils, 3, pt. 3, p. 224, text fig. 14, 1897. Winnipegoceras laticurvatum (Whiteaves), Contr. Mus. Paleont., Univ. Mich., 3, No. 3, pp. 56-58, pi. 9, figs. 1, 2, 1928. Remarks. — This species is represented by an incomplete cast of the interior consisting only of 60 mm. (measuring medially on the lateral side) of the living chamber and the adoral six camerae of the phragmocone. The preserved portion of the phragmocone is about 23 mm. long. The camerae average almost 5 mm. in length, but the adoral two camerae are very short. The specimen strongly resembles Winnipegoceras laticurvatum (Whiteaves) and seems conspecific with it. The degree of convexity of its ventral and dorsal sides respectively appears to 144 ORDOVICIAN FOSSILS OF BAFFIN LAND be essentially the same as that of W. laticurvatum. The elliptical cross section of its living chamber as well as the downward curvature of its sutures of the lateral zone are also quite identical. The siphuncle of the present specimen has not been observed, but presumably it is near the convex outline of the conch, which is very poorly preserved. W. laticurvatum has been reported from the Red River formation of Manitoba and the Lander sandstone of Wyoming. Closely similar forms occur in the Fig. 105. Winnipegoceras laticurvatum (Whiteaves). F.M. No. P28869. Lateral view; natural size. Whitewood dolomite of the Black Hills, South Dakota, and in the Matapedia series of Quebec, Canada. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Genus Neumatoceras Foerste Neumatoceras Foerste, Bull. Sci. Lab. Denison Univ., 30, p. 31, 1935. Genotype: Neumatoceras gibberosum Foerste, Bull. Sci. Lab. Denison Univ., 30, pp. 32- 33, pi. 2, figs. 3, 4, 1935. Original description. — "The genus Neumatoceras differs from Beloitoceras chiefly in being distinctly humped along the upper part of the ventral outline of the phragmocone, the maximum dorso-ventral diameter usually being at a distinct interval beneath the base of the living chamber ventrally. From this level of maximum dorso-ventral diameter the conch usually tapers conspicuously toward the aperture. The dorsal outline along the upper part of the phragmocone Fig. 106. Neumatoceras(?) tumidum (Schuchert). F.M. No. P28870. a, Lateral view. b, Ventral view, c, Dorsal view, d, Dorso-ventral section, showing portion of siphuncle. All natural size. 145 146 ORDOVICIAN FOSSILS OF BAFFIN LAND and all of the living chamber tends to be relatively straight, with faint incurvature at top and along the lower part of the phragmocone." Neumatoceras(P) tumidum (Schuchert) Oncoceras tumidum Schuchert, Proc. U. S. Nat. Mus., 22, p. 172, pi. 14, figs. 1, 3, 1900. Westenoceras{?) tumidum (Schuchert), Bull. Sci. Lab. Denison Univ., 23, pp. 102-103, pi. 8, fig. 7a, b, 1928. Neumatoceras(l) tumidum Foerste, Bull. Sci. Lab. Denison Univ., 30, p. 32, 1935. Remarks. — This species was first described by Schuchert (1900, p. 172) as Oncoceras tumidum. Foerste (1928, pp. 102-103) redescribed it as Westeno- ceras(1) tumidum (Schuchert), and later (1935, p. 32) indicated that probably it should be referred to Neumatoceras. He knew only the adoral portion of the phragmocone and was unable to find any trace of the siphuncle; therefore, he was uncertain as to its generic identity. The specimen now available represents also only the living chamber and the adoral camerae of the phragmocone. A median dorso-ventral section of the specimen, however, shows that the siphuncle is located close to the ventral side of the conch, is small in size, and is composed of subfusiform segments. The septal necks appear to be short and strongly recurved. Compared to the holotype of iV.(?) tumidum, the present specimen is about 30 per cent larger and may represent a distinct species. All of its characters that can be determined, however, do not seem to differ materially from those of the specimen (holotype) originally described by Schuchert. Congeneric forms are known from the upper Ordovician at several localities in Wyoming; near Canyon City, Colorado; and possibly in southern Manitoba and west of Hudson Bay. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Family Phragmoceratidae Hyatt Genus Cyrtogomphoceras Foerste Cyrtogomphoceras Foerste, Bull. Sci. Lab. Denison Univ., 20, p. 267, 1924; Contr. Mus. Paleont., Univ. Mich., 3, No. 3, pp. 58-59, 1928; Bull. Sci. Lab. Denison Univ., 30, pp. 71-72, 1935. Genotype: Oncoceras magnum Whiteaves, Trans. Roy. Soc. Canada, 7, pt. 4, p. 79, pi. 15, fig. 1, 1890; Foerste, Contr. Mus. Paleont., Univ. Mich., 3, No. 3, pp. 59- 60, pi. 6, fig. 1, 1928. Emended description (Foerste, 1935, pp. 71-72). — "Conchs with convex ventral outline, the dorsal outline being slightly gibbous along the top of the phragmocone and the lower part of the living chamber, but more or less distinctly concave along the upper part of the living chamber and the lower part of the phragmocone. The sutures of the septa are nearly directly transverse to the curving vertical axis of the conch along the lower part of the phragmocone DESCRIPTION OF FOSSILS 147 but rise at an increasing angle toward the upper part of the phragmocone, this rise becoming conspicuous near the base of the living chamber. This chamber tapers conspicuously toward its aperture, the margin of the aperture sloping conspicuously downward in a ventral direction, being approximately parallel to the uppermost sutures of the septa. Surface of shell with coarse transverse raised lines which slope downward toward the more convex side of the conch, showing that the latter is to be regarded as ventral, notwithstanding the slope of the aperture at gerontic stages of growth. The siphuncle is located near, but not in contact with the dorsal side of the conch, its location being endogastric. The segments of the conch are nummuloidal, low and broad, but not in contact with the adjacent wall of the conch." Cyrtogomphoceras baffinense Foerste Cyrtogomphoceras baffinense Foerste, Contr. Mus. Paleont., Univ. Mich., 3, No. 3, pp. 63-65, pi. 4, fig. 1, pi. 11, fig. 4, 1928. Remarks. — This species is represented by a single specimen which is a fairly complete right lateral half of the conch. It is weathered, exposing the siphuncle. In general outline and disposition of the sutures it is certainly very close to the species to which it has been referred. It is, however, a smaller form, although mature, as can be judged by the shorter camerae near the adoral end of the phragmocone. The siphuncle is located close to the ventral side and may have been in contact with the wall of the conch. The siphuncle is num- FlG. 107. Cyrtogomphoceras baffinense Foerste. F.M. No. P28871. A weathered right lateral half, exposing the siphuncle. Natural size. 148 ORDOVICIAN FOSSILS OF BAFFIN LAND muloidal in structure and its segments attained a maximum diameter of at least 11 mm. This species is a typical representative of the genus Cyrtogomphoceras. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Cyrtogomphoceras furnishi Roy, sp. nov. A single cast of the interior, consisting of the adapical 15 mm. of the living chamber and the adoral eight camerae of the phragmocone, represents the holo- type of this species. Fig. 108. Cyrtogomphoceras furnishi Roy, sp. nov. F.M. No. P28872. Holotype. a, Left lateral view, b, Right lateral view, c, Ventral view, d, Apertural view, e, Dorso- ventral section, showing a segment of siphuncle close to venter. All natural size. Description. — Conch slightly curved endogastrically; elliptical in cross section. Length as preserved 40 mm.; maximum dorso-ventral diameter slightly apicad of junction of phragmocone and living chamber also 40 mm. Near adoral end of holotype, dorso-ventral diameter, or height, about 36 mm. ; lateral diameter, or width, about 31 mm. Sutures on adapical portion approximately straight and transverse to long axis of conch, rising progressively higher along dorso-lateral sides and forming rounded saddles on crossing the dorsum. On ventral side sutures appear to bend apicad, giving rise to shallow, rounded lobes. DESCRIPTION OF FOSSILS 149 Siphuncle preserved only in apical camerae of specimen; situated close to venter but not in contact with ventral wall of conch. Diameter of siphuncle at adapical end at least 5 mm. Septal necks strongly recurved and segments of siphuncle greatly expanded within the camerae. Siphuncle is thus cyrtochoa- nitic in structure and nummuloidal. Diagnosis. — This species does not seem to be closely related to any described form. Specific comparisons, therefore, are not necessary. Remarks. — This species is named in honor of Dr. W. M. Furnish, of the University of Iowa. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Holotype.—FM. No. P28872. Cyrtogomphoceras sp. I Remarks. — This poorly preserved specimen consists of only a portion of the living chamber and parts of eleven camerae. As preserved, it is 109 mm. long and seems to have attained its maximum diameter (77 mm.) a little apicad of the junction of the phragmocone and the living chamber. The sutures of the adoral part of the phragmocone appear to rise as rapidly along the dorsal part of the conch as is typical of the genus and they are very similar to those of Cyrtogom- phoceras cf. baffinense Foerste (1928, pi. 4, fig. 2). The siphuncle is moderately large and is nummuloidal in structure. In the apical half of the specimen it is located about 5 mm. from the ventral wall of the conch and is practically the same as that of the siphuncle of C. cf. baffinense. It is possible that the two are conspecific but the data at hand are not adequate for certain identification. C. cf. baffinense is from the Richmond of Putnam Highland, Baffin Land. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — John Jaynes. Cyrtogomphoceras sp. II A single internal cast of an incomplete left half of the conch represents this form. Only the adapical 25 mm. of the living chamber and the adoral eight camerae of the phragmocone are preserved. Description. — Conch slightly curved endogastrically. Length as preserved (measured along mid-line) about 70 mm.; maximum width slightly apicad of junction of phragmocone and living chamber 45 mm. Sutures near adapical end nearly straight and approximately transverse to long axis of conch but adorally they rise progressively along dorso-lateral side and form rounded dorsal saddles and rounded ventral lobes. Fig. 109. Cyrlogomphoceras sp. I. F.M. No. P28873. a, Lateral view, b, Dorso- ventral view, showing a portion of siphuncle. Both natural size. 150 DESCRIPTION OF FOSSILS 151 Camerae measured along lateral side of conch average about 5 mm. (adoral two are much shorter, indicating that the specimen had attained at least late maturity). Siphuncle poorly preserved, ventral in position and nummuloidal in form; located very close to ventral wall of conch and may have been in contact with it. Fig. 110. Cyrtogomphoceras sp. II. F.M. No. P28874. a, Lateral view, b, Dorso- ventral half, showing portion of siphuncle. Both natural size. Remarks. — This specimen is so incomplete that specific comparisons are not possible. Its general shape, its sutures, and particularly the nature and position of its siphuncle indicate clearly, however, that it is congeneric with Cyrtogomphoceras. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Genus Diestoceras Foerste Diestoceras Foerste, Bull. Sci. Lab. Denison Univ., 20, p. 262, 1924; 30, pp. 61-62, 1935. Genotype: Gomphoceras indianense Miller and Faber, Jour. Cincinnati Soc. Nat. Hist., 17, p. 137, pi. 7, figs. 3-5, 1894; Foerste, Bull. Sci. Lab. Denison Univ., 20, p. 263, pi. 25, fig. la, b, pi. 26, figs, la, b, 2a, b, pi. 27, fig. 2, 1924. Emended description (Foerste, 1935, pp. 61-62). — "The genotype is a breviconic erect conch, moderately compressed laterally. The conch enlarges as far as the top of the phragmocone and then contracts along the living chamber toward the aperture. At the aperture the marginal part of the wall of the living chamber curves distinctly inward, in a horizontal direction, for a distance of 3 or 4 millimeters. The outline of this aperture tends to be oval, with its ventral side more narrowly rounded. This locates the ventral side of the conch. The 152 ORDOVICIAN FOSSILS OF BAFFIN LAND vertical outline most distant from the siphuncle is slightly more convex than that nearest the latter, and the total length of the camerae along this more convex side of the conch is greater than on its siphuncle side, the sutures of the upper septa tending to rise higher here. From this it is assumed that the affinity of the genus Diestoceras is with that of endogastric conchs. The siphuncle appears to be nummuloidal, and is near the dorsal wall of the conch but not in actual contact with the latter. The surface of the shell is striated transversely, these striae curving downward on the ventral side of the conch, thus locating former positions of the hyponomic sinus." Diestoceras milleri Roy, sp. nov. Only a single cast referable to this genus was collected. Unfortunately, it is badly deformed. Description. — In its present state this species is about 180 mm. long. The phragmocone is rapidly expanded orad, and consists of eleven camerae, all decreasing progressively in length adorally. The adapical camera is about 12 mm. long, and the adoral one measures only 3 mm. The presence of this partic- ularly short adoral camera indicates that the specimen has attained late maturity and presumably reached its maximum size. The sutures appear to have been essentially straight and approximately perpendicular to the long axis of the conch. The siphuncle is dorsal and marginal in position. It is located on the left side of the specimen. The segments of the siphuncle are greatly expanded within the camerae, attaining a maximum diameter of approximately 25 mm. near the adapical end of the specimen. A dorso-ventral section through the siphuncle failed to show the internal structures. Diagnosis. — The only described species of this genus that remotely resembles the present one is Diestoceras magister Foerste from the Lander sandstone of the Big Horn formation, Wyoming. That species, however, is a much larger form with relatively shorter camerae than the specimen under consideration. The Wyoming species has also a decidedly more rotund appearance. Remarks. — The specific name is in honor of Dr. A. K. Miller, of the University of Iowa. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Holotype.—FM. No. P28875. Phylum ARTHROPODA Class Crustacea Subclass Trilobita The trilobites, though not abundant at the head of Frobisher Bay, are represented by all three orders: the Hypoparia by a single genus, Harpes; the JUi 7* Fig. 111. Diestoceras miUeri Roy, sp. nov. F.M. No. P28875. Lateral view, showing traces of siphuncle to left (dorso-lateral). Natural size. 153 154 ORDOVICIAN FOSSILS OF BAFFIN LAND Opisthoparia by five genera, Ischyrotoma{1), Remopleurides, Isotelus, Illaenus, and Bumastus; and the Proparia by seven, Encrinurus, Calymene, Ceraurus, Ceraurinus, Pterygometopus, Calyptaulax and Eomonorachus, a total of thirteen genera. These genera embrace twenty-one species and varieties, of which ten (apparently all new) have been determined. The remaining eleven, because of their fragmentary condition, can not be satisfactorily identified. Order Hypoparia Beecher Family Harpedidae Corda Genus Harpes Goldfuss Harpes sp. ind. Remarks. — This form is represented by three fragments of cephalic shields. None of these, however, displays features which determine its relationship to described species of Harpes. Fig. 112. Harpes sp. ind. F.M. No. P28697. a, Portion of a cephalic shield; natural size, b, Enlargement of a part of the same specimen. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collectors. — John Jaynes and Sharat K. Roy. Order Opisthoparia Beecher Family Solenopleuridae Angelin Genus Ischyrotoma Raymond This genus, with Ischyrotoma twenhofeli Raymond as genotype, was proposed by Raymond in 1925 (p. 54) for a small Opisthoparia "with short, highly convex cephalon, small eyes near the glabella, long, convex, oval glabella with no or inconspicuous lateral furrows, and steeply sloping cheeks which produce a strongly notched appearance at the front of the head." Ischyrotoma(P) raymondi Roy, sp. nov. Description. — Cranidium very small and strongly convex. Glabella longer than wide, rounded at the anterior end and sloping in level with but not over- hanging the anterior border. Posterior end straight. Glabellar furrows, of which a pair is shown, are merely faint impressions. Both are directed backwards and are more or less parallel. Dorsal and occipital furrows deep, which make DESCRIPTION OF FOSSILS 155 the glabella conspicuous. Fixed cheeks steeply sloping. Eyes not preserved; they seem to have lain opposite the two glabellar furrows but not as close to the dorsal furrows as in the genotype. Surface of entire cranidium covered with small, unequal pustules. Diagnosis. — This species differs from the only other described species, Ischyrotoma twenhofeli Raymond, in having a relatively wider and less over- hanging glabella. The eyes are farther away from the dor- sal furrows, and the posterior border of the fixed cheek is slightly curved forward or sinuous, but not rounded as in i". twenhofeli. Antero-posterior diameter of glabella 2.8 mm., width of the posterior end 2 mm. Remarks. — /. twenhofeli from the upper Chazy(?) is represented by two specimens, one of which was collected from a pebble in Cow Head conglomerate at Lower Head, Newfoundland, and the other from a boulder in conglom- erate, two miles north of Mystic, Quebec, Canada. The questionable reference of the present species to this genus is due to the damaged condition of the speci- men and to the uncertainty regarding the exact position of the eyes. There is, however, no other genus in which it could be more appropriately placed. This interesting specimen is named in honor of Dr. Percy E. Raymond, of Harvard University. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Fig. 113. Ischy- rotomaC!) raymondi Roy, sp. nov. F.M. No. P28698. Holo- type. A damaged cranidium; X 4. Collector.- Holotype. -Sharat K. Roy. -F.M. No. P28698. Family Remopleuridae Corda Genus Remopleurides Portlock Remopleurides sp. Remarks. — This form in general resembles the Trenton species Remopleu rides striatulus Walcott but differs in the following charac- ters: (1) The buccal notch is wider and rounded; (2) the mus- cular scars are more kidney-shaped than oval and situated closer to each other; and (3) the elevated lines on the sur- face are less regularly disposed. There is little doubt that the specimen under consider- ation represents a new species, but since it is only an incom- plete hypostoma it cannot very well serve as a type. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Fig. 114. Remo- pleurides sp. F.M. No. P28699. X 6. 156 ORDOVICIAN FOSSILS OF BAFFIN LAND Family Asaphidae Burmeister Subfamily Asaphinae Raymond Genus Isotelus DeKay Isotelus gigas latior Roy, var. nov. This variety is represented by a well-preserved hypostoma. The incomplete pygidium included here is of a different individual. It may or may not belong to this variety. Fig. 115. Isotelus gigas latior Roy, var. nov. a, A hypostoma. F.M. No. P28700. Holotype. X 5/6. b, A broken pygidium. F.M. No. P28700A. Natural size. Diagnosis. —The wings of the hypostoma, for their length, are much wider and situated much farther apart than in Isotelus gigas, to which it is most closely related. The pygidium is broken and damaged but enough of it is preserved to indicate that it is a variant of i". gigas DeKay. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Holotype.— -F.M. No. P28700. Isotelus cf. I. iowensis (Owen) Remarks. — This pygidium approaches Isotelus iowensis (Owen) from the Richmond of Iowa in general outline, shape of its axial lobe, and border, but, on account of its fragmentary nature, identi- fication is not possible. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Fig. 116. Isote- lus cf. /. iowensis (Owen). F.M. No. P28701. Natural size. Family Illaenidae Corda Genus Illaenus Dalman IUaenus baffinlandicus Roy, sp. nov. Diagnosis.— The pygidium of this species shows close affinity to Illaenus consimilis Billings, /. groenlandicus Troedsson, and /. americanus (Billings). It DESCRIPTION OF FOSSILS 157 is, however, closer to I. consimilis than the other two, differing mainly in smaller size and in the proportion of its length to width, 2:3, compared to 1:2 in 7. con- similis. The same proportional difference may also be applied to distinguish the present species from I. groenlandicus. From I. americanus it differs in having a more projected axis and less obliquely truncated anterior angles. The surface ornamentation of this pygidium is somewhat like that of I. consimilis, being marked with wavy, branching lines. This is not the case, however, with either I. americanus Fig. 117. Illaenus baffinlandicus Roy, sp. nov. F.M. No. P28703. Holotype. a, An incomplete cranidium. b, A pygidium. Both X 1H- or I. groenlandicus. In the former the surface striae seem "to radiate irregularly from the axis as a centre" (Billings, 1865, p. 330), and in the latter "the striae cross the axis, curving more or less forward; from the axis they radiate over the pleural portion, sometimes being united by an additional line, which runs inside and parallel to the dorsal furrows." (Troedsson, 1928, p. 36.) Length of pygidium 16 mm., width 24 mm. Length of the axis 8.5 mm., width at the anterior extremity 9.2 mm. Remarks. — The cranidium of this species is incomplete and in a very poor state of preservation. Only the glabella, which is wide (width at the posterior end 12 mm.) and bounded by almost parallel dorsal furrows like that of I. con- similis, can be described with any degree of certainty. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Holotype.— F.M. No. P28703. Illaenus punctatus Roy, sp. nov. Diagnosis. — This species bears some resemblance to Illaenus angusticollis Billings and I. groenlandicus Troedsson, but can be distinguished readily from both. It differs from I. angusticollis in having wider and shorter glabella and in having its eyes situated closer to the posterior margin. From I. groenlandicus it differs in the following characters: Head less convex dorso-ventrally; glabella longer and much less convex; dorsal furrows longer and deeper but less wide, the course of the furrows almost similar to that of I. angusticollis — a gentle inward curve from the posterior margin and then an abrupt outward turn before fading out; eyes more widely separated; entire surface densely covered, in net-like fashion, with irregular punctae of varying size. The punctae are larger and more 158 ORDOVICIAN FOSSILS OF BAFFIN LAND irregular in the glabella than on any other part, but unlike that of I. groenlandi- cus, the glabella of the present species is entirely free from any elevated striae. Antero-posterior diameter of cranidium 17 mm. Width of glabella at the posterior margin 12.1 mm. Distance from the dorsal furrow to the eye 9 mm. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Fig. 118. Illaenus puncta- Collector. — Sharat K. Roy. lUS Roy, SD. nOV. F.M. No. TT . . ru XT -nnorrrn P28704. Holotype. A crani- Holotype.— F.M. No. P28704. dium; X 1H- Illaenus cf. I. groenlandicus Troedsson Remarks. — There are four pygidia representing this form. All resemble Troedsson's figure (1928, pi. 13, fig. 18) of Illaenus groenlandicus, differing mainly c Fig. 119. Illaenus cf. I. groenlandicus Troedsson. F.M. No. P28705. Pygidia; X 3 and X 2, respectively. in the proportion of length to width and in their convexities. No cranidium has been found in association with these pygidia. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collectors. — John Jaynes and Sharat K. Roy. Illaenus sp. ind. Remarks. — This form is preserved as an internal mold of a portion of a cranidium. The preserved portion, however, is not suffi- ^^^ cient for adequate description or specific determination. Judging from the deep concavity of the mold it can be inferred that the cephalon is highly convex antero-poste- riorly. Glabella short, about one-third of the length of the cephalon. Dorsal furrows short, deep, running first obliquely inward from the posterior margin, then turn- ing abruptly outward and fading out within a distance of about 3 mm. Surface sparingly pitted. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Fig. 120. Illaenus sp. ind. F.M. No. P28706. Internal mold of a por- tion of a cranidium; natural size. DESCRIPTION OF FOSSILS 159 Genus Bumastus Murchison Bumastus sp. ind. Remarks. — This genus is represented in the collection by a badly damaged head and a pygidium which is not complete, although rather well preserved. It is not known if the two are conspecific. The head is so badly damaged that specific identification is not possible. The pygidium resembles that of Bumastus 9- Fig. 121. Bumastus sp. ind. F.M. No. P28707. a, A damaged head; natural size. b, A pygidium; X 1%. aplatus Raymond from the lower Chazy of Vermont and Tennessee, but differs in having a more projected anterior border of the axial lobe, which is only faintly outlined. In the absence of better material, no attempt has been made at definite identification. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Order Proparia Beecher Family Encrinuridae Angelin Genus Encrinurus Emmrich Encrinurus sp. ind. Remarks. — There are two glabellae in the present collection. In general appearance both show a certain likeness to Encrinurus rarus (Walcott) from the Black River of Wisconsin, but the speci- mens are so badly damaged and so fragmentary that it has not been possible to make detailed comparison with that species. Both specimens, however, have retained just enough characters for generic diagnosis. Horizon and locality. — Richmond. Silliman's Fossil FlG 12 2. En- Mount, Frobisher Bay, Baffin Land. crinurus sp. ind. r> n 4 cu _4. tt j> F.M. No. P28708. Collector.— Sharat K. Roy. A fragmentary gla- bella; X 6. Family Galymenidae Milne-Edwards Genus Calymene Brongniart Specimens of Calymene from the Ordovician, as has been pointed out by Raymond (1916, p. 27), "are difficult fossils to differentiate satisfactorily." 160 ORDOVICIAN FOSSILS OF BAFFIN LAND The reason seems to be that there are a number of similar forms whose character- istics are not sharply fixed or sufficiently constant for certain differentiation. An investigator trying to distinguish between two species often "feels" the differences but finds it most confusing and difficult to express them in words. I have met with these difficulties in attempting to decide whether the four cephala upon which Calymene croneisi Roy, sp. nov. is based are really conspecific. The relative sizes of the glabellar lobes are not quite the same in all; the convexi- ties of the cephala vary, though not noticeably; and lastly, the amount of diver- gence of the dorsal furrows is by no means identical. These cephala, therefore, are not exactly alike, yet it has not been possible to find any differences of sufficient significance to separate them. According to Foerste (1919, p. 79), American Ordovician species of Calymene "have the abbreviated form of glabella with the strongly divergent dorsal furrows," whereas the Silurian species "have the more elongate form of glabella, with the more moderately divergent dorsal furrows." Foerste's observation regarding the Silu- rian forms is fully in accord with the evidence at Fig. 123. Calymene plaiy- h an d but the same cannot be said to apply to all species from the Ordovician. The form of the glabella of Calymene platycephala Foerste (1910, pi. 2, fig. 7) from the Trenton of Tennessee, described by Foerste himself, can hardly be regarded as abbre- viated nor can its dorsal furrows be called strongly divergent (fig. 123). The discovery of four cephala of Calymene croneisi in Silliman's Fossil Mount, all having a decidedly elongate glabella with moderately divergent dorsal furrows, renders Foerste's statement regarding the glabellar characteristics of Ordovician • Calymenes still more untenable. This is, however, only to be expected. To conceive of a sudden jump from an abbreviated Ordovician to an elongate Silurian form would not be in keeping with present conceptions of structural evolution and of speciation. Two such extremes are usually, if not always, connected by intermediate forms and it is the failure to find or to recognize intermediates, not their lack of existence, that sometimes leads to the formulation of such apparently erroneous hypotheses as "magnimutation." Calymene croneisi Roy, sp. nov. Diagnosis. — The cephalon of this species strongly resembles Calymene senaria Conrad, but it is a more slender and a more delicate form. Its chief distinguishing features are the following: Glabella more elongate; frontal lobe sloping more abruptly; preglabellar field more deeply excavated; front border between sutures of fixed cheeks more elevated and more strongly arched; and dorsal furrows less divergent, the portions bounding the second and third glabellar lobes being almost parallel. The pygidium also, so far as it can be judged from the description and figures, is like that of C. senaria, differing only in minor details. The more salient features DESCRIPTION OF FOSSILS 161 of the pygidium of the present species are as follows: Subtrigonal, but the anterior margin rounded, imparting a more or less transversely suboval form to the general outline. Distinctly trilobed. Axis strongly convex; gently tapering; posterior extremity rounded; annulations eight, the last one not distinct. Ring furrows moderately deep and well defined anteriorly, becoming faint and obsolete posteriorly. Postaxial ridge short and turned up at the tip. Pleural lobes strongly deflected. Pleurae five or six, the last two not well defined, but all reaching (or nearly so) the margin, which is incurved. Rib furrows only slightly 4ES mi Fig. 124. Calymene croneisi Roy, sp. nov. a, d, Holotype. F.M. No. P28709. o, Cephalon; x 3. d, Pygidium; X 4. b, c, Cephalons. F.M. No. P28710. Paratypes; X 3. deeper than pleural furrows, all of which have their beginning at the axial furrow. Anterior bands of the pleurae wider than the posterior ones. Surface densely dotted with minute but unequal pustules. The length of the best-preserved and the largest cephalon (holotype) is 7 mm., and of the glabella 4.5 mm. Width at the posterior margins of the facial sutures 12.2 mm. Width of the occipital ring 4.8 mm. Width between eyes 8 mm. Pygidium (holotype), length 3.5 mm., width 5 mm. Length of the axis 3 mm., width of the axis at the anterior end 2.1 mm. Remarks. — There are four cephala and two pygidia of this species in the collection. They were found independent of one another, but in adjacent slabs. The matrix and the nature of preservation of the specimens, however, are identical and it may, therefore, be safely assumed that they are parts of the same species. The specific name is in honor of Dr. Carey Croneis, University of Chicago. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collectors. — Sharat K. Roy and John Jaynes. Holotype.— F.M. No. P28709. Calymene macmillani Roy, sp. nov. Diagnosis. — In general, the pygidium of this species resembles that of Calymene croneisi Roy. The angle at the posterior extremity between the incurved lateral margins, however, is less acute. The axis is wider and less con- vex, its posterior end less rounded, almost straight. Annulations fewer, being only six and separated by deeper furrows. The pleural lobes are less abruptly 162 ORDOVICIAN FOSSILS OF BAFFIN LAND deflected, with fewer pleurae (five on each), none reaching the margins. The most noticeable distinguishing feature is the character of the pleural furrow, which is fainter and, unlike in C. croneisi, does not begin at the axial furrow but at some distance from it. The last pleura is coalesced with the posterior axial ridge, showing no impression of a pleural furrow. Surface of the pygidium smooth or sparsely pitted, a condition which may be due to mechanical abrasion. Length 4.5 mm., width 6 mm. Length of the axis 3.4 mm. Width of the axis at the anterior end 2.7 mm. Remarks. — The cephalon and thorax of this species are not known. The specific name is in honor of Lieutenant Comman- der Donald B. MacMillan, Provincetown, Massachusetts. „ 1f> _ „ , Horizon and locality.— Richmond. Silliman's Fossil Fig. 125. Calymene __ t-. i_- i t» ™ ^ t i macmillani Roy, sp. Mount, Frobisher Bay, Baffin Land. nov. F.M. No P28711. Collector.— Sharat K. Roy. Holotype. A pygi- dium; x 434 Holotype.— FM. No. P28711. Family Cheiruridae Salter Subfamily Cheirurinae Raymond Genus Ceraurus Green Ceraurus cf. C. horridus Troedsson Remarks. — This form is represented by a glabella and an occipital ring Both are suggestive of Ceraurus horridus Troedsson, but neither is sufficiently well preserved for certain identification. C. horridus occurs in the Richmond portion of the Cape Calhoun beds at Cape Calhoun, Greenland. It has been adequately described by Troedsson (1928, pp. 65-67) and is an easily distinguishable species. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — John Jaynes. Fig. 126. Cerau- rus cf. C. horridus Troedsson. F.M. No. P28712. An incom- plete glabella; X 2. Remarks. Fig. 127. Ceraurus sp F.M. No. P28713. Acau dal spine; X4J^. Ceraurus sp. There are three caudal spines representing this genus. They resemble those of Ceraurus tuberosus Troedsson and may belong to that species. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. DESCRIPTION OF FOSSILS 163 Ceraurinus icarus noduliferus Roy, var. nov. Diagnosis. — The glabella agrees with the description of Ceraurinus icarus (Billings), differing in having a central node on the occipital ring. Remarks. — A portion of the obtuse points of the back- ward curving extremities of the articulations of a pygidium is also present in this collection. It probably belongs to this variety. Ceraurinus icarus has been found in widely distrib- uted areas, in Greenland, in the Island of Anticosti, in Manitoba, Iowa, Indiana, and Ohio, but is restricted to the Richmond. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Holotype.—F.M. No. P28714. Fig. 128. Cerau- rinus icarus nodu- liferus Roy, var. nov. F.M. No. P28714. Holotype. A glabella; x 2^. Family Phacopidae Corda Subfamily Pterygometopinae Reed Genus Pterygometopus Schmidt Delo (1935, p. 417) has recently erected the genus Calliops for Pterygometopus callicephalus (Hall). It is questionable, however, if this species warrants generic separation. In his discussion of Calliops, Delo states (p. 417) : "The genus differs primarily from Pterygometopus s.s. as typified by P. sclerops (Dalman) in the less alate frontal lobe which slopes abruptly to the cephalic border. In P. sclerops the Fig. 129. a, Pterygometopus callicephalus (Hall), as shown by Delo (1935, fig. 42). b, "Pterygometopus callicephalus," lateral lobes are more or less elliptical, grading downward in size backward, the first lobe much narrower than the frontal. In Calliops, by contrast, the first lateral lobes are very large, definitely triangular, and only slightly shorter than the frontal lobe . . . ." The above reasons as basis for generic separation are not convincing. It may be true that the frontal lobe of P. callicephalus is less alate, but this can hardly be regarded as a generic character. The degree of alation of the frontal lobe of different species of Pterygometopus s.s. is variable. In regard to the abrupt sloping of the frontal lobe to the cephalic border in P. callicephalus, Delo's observation is not in accord with conditions in the type specimen of that 164 ORDOVICIAN FOSSILS OF BAFFIN LAND species. In fact, the line drawing given by him of P. callicephalus (1935, fig. 42; fig. 129, b, of this paper), showing the frontal lobe reaching the anterior margin, is not accurate. P. callicephalus has a narrower anterior border (see fig. 129, a), Fig. 130. Diagrams showing forms of different genera belonging to subfamily Ptery- gometopinae. a, Pterygometopus. b, Chasmops. c, Monorakos. d, Eomonorachus. e, Calyptaulax. f, Ackatella. and the frontal lobe is cut laterally by the facial suture characteristic of Ptery- gometopus. Furthermore, it is not correct that the first lateral lobe of P. calli- cephalus is "only slightly shorter than the frontal lobe." Measurements of the first lateral and frontal lobes show that the former is less than one-half as large as the latter. Other distinguishing features mentioned by Delo are of lesser importance and need not be discussed here. DESCRIPTION OF FOSSILS 165 It is highly possible that all the species now placed in Pterygometopus s.s. are not congeneric and a more careful revision of that genus is needed. But until such revision 1 is made it would be inconsistent, if not confusing, to accept P. callicephalus as the type of a new genus. There are other species of Ptery- gometopus equally different, which could be placed for similar reasons in new genera. P. schmidti Clarke may be taken as an example. It is similar to P. calli- cephalus, differing mainly in the absence of genal spines. It could be separated from P. sclerops and referred to a new genus as readily as, if not more so (because of its genal spines) than P. callicephalus. At present the following six genera (Fig. 130, a-J) belonging to the subfamily Pterygometopinae seem valid: Pterygometopus Schmidt, Calyptaulax Cooper, Eomonorachus Delo, Chasmops McCoy, Monorakos Schmidt, and Achatella Delo. Pterygometopus callicephalus brevis Roy, var. nov. Diagnosis. — The cephalon of this variety is distinctly smaller and more convex than that of Pterygometopus callicephalus (Hall). The most noticeable ^F Fig. 131. Pterygometopus callicephalus brevis Roy, var. nov. F.M. No. P28715. Holo- type. a, Cephalon. b, Pygidium. Both X 2. difference is its somewhat curved anterior furrows, which make the frontal lobe appear suboval. The glabella is more rapidly expanding, and the eyes are relatively larger. The pygidium in all important features answers the description of P. calli- ceplialus given by Clarke (1894, p. 731) and need not be redescribed here. Length of glabella including the neck ring 6.9 mm. Length of the frontal lobe 4 mm., width 5.8 mm. Length of eye 4 mm. Length of pygidium 7 mm., width (as preserved) 7.5 mm., length of axis 5.8 mm., width at anterior end 3 mm. Remarks. — This variety is based on an incomplete cephalon and two pygidia. The cephalon and one of the two pygidia (F.M. No. P28715) probably belong to the same individual. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collectors. — John Jaynes and Sharat K. Roy. Holotype.— F.M. No. P28715. 1 It is hoped that when and if this revision is made the author will, as far as practicable, base his differen- tiations on actual specimens. Old original illustrations, particularly drawings, are frequently misleading and are often not sufficient for the determination of differential characters. 166 ORDOVICIAN FOSSILS OF BAFFIN LAND Pterygometopus sp. ind. I Description. — Pygidium subtriangular; wider than long. Axis moderately convex, gently tapering, not reaching the posterior end. Pleural lobes slope gently near the dorsal furrows, and then abruptly. Annulations on both the axis and pleurae very faint, probably due to a film of ^^ calcareous incrustation. Pleurae do not reach the lateral margins, which are slightly elevated. Length 4.9 mm., width 6 mm. Length of the axis ,™ ™ 3.7 mm. Fig. 132. Pterygo- metopus sp. ind. I. Remarks. — This pygidium probably belongs to a young F.M. No. P28717. A Pterygometopus callicephalus (Hall), but its poor state of pygidium; X 3i^. "* ,. j . n . • preservation does not allow more accurate comparison. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Pterygometopus sp. ind. II Remarks. — This incomplete left pleural lobe shows eight pleurae, all of which are faintly grooved but none of which reaches the mar- gins. The specimen is too fragmentary for identification. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. -Shzvzt K. Roy. JftX. SHE F.M. No. P28718. A left pleural lobe of a pygidium; X 2J^. Genus Calyptaulax Cooper The genus Calyptaulax was proposed by Cooper in 1930 (p. 386) for a phacopid trilobite having generic relationships with certain American forms usually referred to Pterygometopus. Its chief generic character is "the coales- cence of the first and second glabellar lobes, the second glabellar furrow being reduced to a faint impression, and the reduction of the third glabellar lobes to tubercles situated directly posterior to the coalesced lobes." The genotype is Calyptaulax glabella Cooper from the upper Ordovician at South Cove, Perce, Quebec, Canada. Cooper has described another species, Calyptaulax compressa, from the same locality and has placed the following American species in this genus: Monorakos schucherti Troedsson, M. wimani Troedsson, Pterygometopus goodridgii Schuchert, P. eboraceus Clarke, P. lincolnensis Branson, P. confluens Foerste and P. holstonevisis Raymond. According to Cooper Calyptaulax is restricted to American deposits (Cooper, 1930, p. 388), but Delo extends its occurrence to the British Isles (Delo, 1935, p. 416). The only British phacopid species that may belong to the genus is DESCRIPTION OF FOSSILS 167 Phacops brongniarti Portlock (Salter, 1864, p. 34, pi. 1, figs. 20-26). It is not certain, however, that it is a Calyptaulax. Of the nine figures given by Salter, only one (fig. 20, a, a drawing) shows the generic character of Calyptaulax, namely, the coalescence of the first and second glabellar lobes, since the second lateral furrows do not reach the dorsal furrow. The British specimens are of Caradocian age, which is roughly equivalent to the Richmond of America. Calyptaulax sillimani Roy, sp. nov. Description. — Cephalon sub-semicircular with a central short projection at the anterior extremity. The general outline is not unlike that of Calyptaulax goodridgii (Schuchert). The glabella, however, is distinctive and unlike all other described species of the genus. The frontal lobe is large, occupying more than one-half of the glabella. Its anterior portion is also very wide (5 mm.) but the width diminishes rapidly posteriorly, giving it the shape of an inverted tri- angle. The median portion between the first and second Fig. 134. Calyp- lobes is very narrow and convex, but widens suddenly and taulax sillirmni Roy, becomes less convex as it reaches the neck furrow. The P28719. Holotype! fi™* lobes are subpentagonal, the second subrectangular. Cast 1 of cephalon The basal lobes are very small, their outer extremities from natural mold; merely isolated> small tubercles. The anterior glabellar furrows are directed obliquely forward and well defined, but the second furrows are only short incisions at the inner extremities. This makes the first and second lobes coalesce along the dorsal furrows into one large subpentagonal lobe. Neck furrow narrow, but deeply grooved. Neck ring wide (1.5 mm.) and strongly convex. Palpebral lobes small; eyes large, extending from the anterior glabellar furrows to the neck furrow. The large size of the eyes renders both cheeks small. Marginal border wide but the width is not constant in its entire course. Genal angles produced into short spines like those of Calyptaulax goodridgii. Surface of cephalon smooth except the frontal lobe, which is granulated. Thorax and pygidium unknown. Length on median line from the posterior to the anterior margins 8.2 mm. Width at points of the spines 12.8 mm. Length of the glabella 5.4 mm., width of the glabella at the anterior margin 5 mm., at the inner extremities of the first glabellar furrows 1.1 mm., and at the occipital furrow 2 mm. Diagnosis. — C. sillimani can be readily distinguished from all other species of the genus by its elongate, subtriangular frontal lobe. Its very narrow and steep median portion between the first and second lobes and its wide marginal borders are other distinguishing features. 1 Since the description was written the cast has unfortunately been mislaid. ■ It has, therefore, been necessary to photograph an artificial cast taken from the natural mold. Because of defects in the mold this artificial cast does not show clearly all the features seen in the original cast. 168 ORDOVICIAN FOSSILS OF BAFFIN LAND Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Holotype.—FM. No. P28719. Genus Eomonorachus Delo This genus was proposed by Delo (1935, p. 417) to mark "a stage in the phylogenetic sequence within the Pterygometopinae between Pterygometopus s.s. and Calyptaulax Cooper. Pterygometopus has the second lateral furrows deeper distally, meeting the dorsal furrows at their level. In Eomonorachus the second lateral furrows are complete, but do not reach the dorsal furrows at their level, and are deepest at their mesial ends. A further change is noted in Calyp- taulax in which the second lateral furrows are incomplete." The genotype selected was Pterygometopus intermedius (Walcott) (see also Delo, 1935, p. 417) from the Black River. With the exception of the species described here the genotype is the only other known species of this genus. Eomonorachus deloi Roy, sp. nov. Description. — Sublunate in outline. Glabella large, depressed convex, rapidly enlarging anteriorly. Frontal lobe transversely suboval, rounded laterally and at the front; large, more than half as long as the glabella and bordered by a narrow margin which, unlike described spe- cies of Pterygometopus, is barely pointed at the anterior extremity. Anterior pair of glabellar furrows doubly curved like that of Calyptaulax holstonensis (Raymond); second pair shorter and directed obliquely backward; third pair still shorter and directed more obliquely than the second Fig 135 Eomono- P a * r * ^ re ^ P a * r °^ kteral lobes sub triangular; second pair rachus deloi Roy, rectangular; third pair obscurely outlined. Median region p?R75>n V ' tT i^t N °" depressed, becoming convex near the occipital furrow. An incomplete ceph- Occipital ring moderately large, convex. Dorsal furrows alon; x 2$/%. well excavated. Palpebral lobes prominent. Surface densely tuberculate. Except for a few facets of the left eye, the other features of the cephalon are not preserved. Length on median line from posterior to anterior margins 9 mm. Length of the glabella excluding the neck ring 7.5 mm. Width at anterior lobes 7 mm. Diagnosis. — The present species, though based on an incomplete cephalon, can be readily distinguished from the genotype by the suboval shape of its frontal lobe, by its doubly curved anterior lateral furrows and by the almost rounded anterior extremity of its marginal border. Remarks. — The specific name is in honor of Dr. David M. Delo, of Knox College, Galesburg, Illinois. DESCRIPTION OF FOSSILS 169 Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Holotype.—FM. No. P28720. Subclass Eucrustacea Kingsley Superorder Ostracoda Latreille Ostracods are not as plentiful in this collection as might be desired. Only eleven species of ostracods representing eight genera have been described here. Doubtless many more occur at the locality under consideration but because of their microscopic size they have escaped attention both in the field and in the laboratory. Superfamily Leperditacea Family Leperditiidae Jones Genus Leperditia Rouault Emended description (Bassler, 1934, p. 14). — "Shell suboblong with an oblique backward swing, usually large, commonly exceeding 8 mm. in length. Ventral edge thick, formed by the overlap of the right valve. Valves strongly unequal, the right the larger and widely overlapping the ventral edge of the left; hinge simple. A small tubercle, or 'eye-spot,' is generally present on the anterodorsal fourth, while a large, rounded, subcentrally situated muscular imprint is a well-marked feature of the interior and is sometimes distinguish- able even on the exterior." Genotype. — Leperditia crittanica Rouault. Leperditia cf. L. ulrichi Troedsson Leperditia ulrichi Troedsson, Medd. om Gr0nland, 72, p. 80, pi. 19, figs. 24, 25, 1928. Remarks. — Two right valves represent this form. Length and height of the larger one are 6.5 mm. and 4 mm. respectively; of the smaller one 4.9 mm. and □ Fig. 136. Leperditia cf. L. ulrichi Troedsson. F.M. No. P28876. a, Right valve. b, Right valve of another individual. Both X 2. 2.9 mm. respectively. Both valves agree closely in all essential features (straight hinge line, high shape, and maximum convexity on the center of the valves) with Leperditia ulrichi Troedsson except that they are a little more elongate. 170 ORDOVICIAN FOSSILS OF BAFFIN LAND L. ulrichi is from the Richmond of Cape Calhoun beds, Cape Calhoun, Greenland. According to Bassler (1934, p. 381) it is the same species as Leper- ditia cabotensis Ulrich and Bassler, from near Cabot Head, Ontario. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Genus Isochilina Jones Emended description (Bassler, 1934, p. 14). — "Like Leperditia except that exteriorly the valves do not overlap but seem to be equal in every respect. In reality, within the left valve there is a sloping area that is overlapped by a corresponding leveled edge of the right valve. Surface sometimes lobulate or nodose." Genotype. — Isochilina Ottawa Jones. Isochilina convexa Roy, sp. nov. Three specimens represent this species. Description. — Suboblong in outline with obliquely truncated posterior and anterior ends; rounded ventrally. Valves with strong convexity, like that of a broadly sloping low cone, the maximum convexity being at the center. Hinge ED □ Fig. 137. Isochilina convexa Roy, sp. nov. F.M. No. P28877. a, Right valve; holotype. b, c, Two left valves. All x 3. The three valves illustrated are from different individuals. line straight, about two-thirds the greatest length of the shell. Surface, except for the eye-spot on the antero-dorsal third (2 mm. posterior to the anterior end and 1.5 mm. below the dorsal edge), smooth. The holotype (a right valve, fig. 137, a) is 5.1 mm. long and 3.9 mm. high. Of the two left valves, the larger one is 6.1 mm. long and 5 mm. high, the smaller one 5.2 mm. long and 4.1 mm. high. Diagnosis. — The species approaches Isochilina vaurealensis Twenhofel from the Richmond of Vaureal Falls, Anticosti Island, but differs in its greater con- vexity, smooth surface, and more posteriorly placed antero-dorsal tubercle. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Holotype.— -F.M. No. P28877. DESCRIPTION OF FOSSILS 171 Family Leperditellidae Ulrich and Bassler Genus Aparchites Jones Emended description (Bassler, 1934, p. 14).— "Shell not extending 3 mm. in length, equivalent, subovate or oblong; hinge straight, ventral edge thickened, often beveled or channeled; surface convex, mostly in the ventral half, smooth." Genotype. — Aparchites whiteavesi Jones. Aparchites(?) sp. Description. — This form is represented by a single specimen damaged along the antero-ventral edge so that its exact outline can not be determined. Length 2.9 mm., height 2.4 mm., and width 1.9 mm. Left valve slightly pro- H H Q Fig. 138. AparchitesC!) sp. F.M. No. P28878. a, Right valve, b, Left valve, c, Dorsal edge. All X 5. truded over the right about the middle of the hinge line. Edges of the valves considerably thickened but apparently not overlapping. Surface convex (the convexity increasing toward the posterior region) and concentrically pitted. This concentric arrangement of the pits is best seen around the rounded sub- centrally placed muscular imprint. Diagnosis. — The questionable generic reference of this form is chiefly due to the fact that its surface is ornamented instead of being smooth, which is believed to be a diagnostic feature of the members of the family Leperditellidae. On the other hand, the specimen has protruding dorsal region and thickened edges, both of which are good determinative characters of the genus Aparchites. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Superfamily Beyrichiacea Family Primitiidae Ulrich and Bassler Subfamily Primitiinae Genus Primitia Jones and Holl Emended description (Bassler, 1934, p. 17). — "Distinguished from Primitiella by having a well-marked subcentral, usually curved sulcus with undefined swell- ings or low nodes on one or both sides of it instead of an undefined depression. As a rule also the valves are shorter, the outline being generally more ovate." Genotype. — Primitia mundula Jones. 172 ORDOVICIAN FOSSILS OF BAFFIN LAND Primitia cincinnatiensis (Miller) Primitia cincinnatiensis (Miller). See R. S. Bassler, Geol. Soc. Amer., Special Papers, 1, p. 440, 1934, for references to literature and synonyms. Remarks. — There are two specimens of this species, one of which is a slightly damaged right valve, the other a well-preserved left valve. Fig. 139. Primitia cincinnatiensis (Miller). F.M. No. P28879. o, Right valve. b, Left valve. Both x 15. Primitia cincinnatiensis (Miller) occurs in the Richmond of various localities in Ohio, Indiana, and Michigan. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Genus Halliella Emended description (Bassler, 1934, p. 17). — "Like Euprimitia, but with broader sulcus and very coarsely reticulate surface which rises to greatest height in antero-dorsal quarter. Thick double border." Genotype. — Halliella retifera Ulrich. Halliella jaynesi Roy, sp. nov. Description. — Valves broadly oval with a strongly convex body encircled by a narrow border which is convex except in the ventral portion where it is concave and upturned. Cardinal line nearly straight, much shorter than the C3 □ Fig. 140. HallieUa jaynesi Roy, sp. nov. F.M. No. P28880. Holotype. a, Right valve. 6, Left valve, c, Dorsal view, d, Ventral view. All x 4. greatest length of the shell. Anterior end a little narrower than the posterior end; both ends rounded. Edges of the valves thick, bevelled dorsally, lip-like ventrally. There is a trace of a sulcus in the central part of the upper half, and each valve has a slightly elevated rounded spot at the center. Surface marked by minute pustules among which are dispersed irregularly a few larger ones. Length 3.5 mm., height 2.9 mm., width 2 mm. DESCRIPTION OF FOSSILS 173 Diagnosis. — Of the two Ordovician species known of this genus — HaUiella sculptilis (Ulrich) from the Trenton (Perryville) of Kentucky and HaUiella labiosa Ulrich from the Trenton (Prosser) of Minnesota — -the present species resembles the latter in general outline and in the thick lip-like ventral edge; otherwise it is so different that further comparisons are unnecessary. Remarks. — The specific name is in honor of Mr. John Jaynes, who served as engineer in the expedition schooner, the Bowdoin. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Holotype.—FM. No. P28880. Subfamily Eurychilininae Ulrich and Bassler Genus Eurychilina Ulrich Emended description (Bassler, 1934, p. 20). — "Oblong or semi-elliptical, long-hinged shells having a subcentral Primitian sulcus, the posterior edge of which is often raised into a small rounded node; free margins provided with a wide, usually radiately plicated, frill-like border curved on its under side so as to form a concave area around the true contact edge of the valves." Genotype. — Eurychilina reticulata Ulrich. Eurychilina bassleri Roy, sp. nov. This description is based on a nearly perfect left valve. Description. — Semi-circular in outline. Body strongly convex, sloping abruptly toward the inner edge of the marginal area to form a depressed border from end to end. Cardinal line straight, about as long as the greatest width of the valve. Anterior and posterior ends approximately straight, curving inward ventrally. Sulcus subcentral, deep and wide, beginning within the dorsal margin and extending a little more than halfway across the body. Below the sulcus the surface is elevated, forming an obtuse ridge-like prominence which is terminated on its posterior side by a Fig. 141. Eury- large, rounded node. Marginal area strongly convex and Roy^nov^F M* of nearly uniform width in the ventral region, becoming No.P28881. Holo- narrower as the dorsal angles at each end are approached. tv Pe- L*^ valve; There is an indication that the border of the marginal area is reflexed. Surface irregularly pitted except around a line parallel to and a short distance below the inner edge of the marginal area where the pittings appear to be more or less uniformly arranged. Length 2.2 mm., height 1.5 mm. Diagnosis. — This species is related to Eurychilina manitobensis Ulrich from the Richmond of Manitoba but differs in its greater convexity of the body and pitted surface. l-^J 174 ORDOVICIAN FOSSILS OF BAFFIN LAND Remarks. — The specific name is in honor of Dr. R. S. Bassler, of the United States National Museum. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Holotype.—FM. No. P28881. Eurychilina sp. Description. — This form is represented by a single external mold of a left valve. The specimen, however, is not well enough preserved for detailed descrip- tion. It is 2 mm. long and 1.4 mm. high, semicircular in outline with a convex body. Cardinal line straight, a little shorter than the greatest width of the shell. Anterior and posterior ends almost straight, becoming rounded ventrally. Sulcus subcentral, with a prominent node behind it. Marginal area concave, with indications that it is frilled and that it has a narrow Fig. 142. Eury- upturned outer edge. Surface pitted. No* P28882. Ex- Diagnosis. — The only member of the genus that resembles temal mold of a this species seems to be Eurychilina frobisheri (Emerson), left valve; x 9. ^ut the illustrations (drawings) of that species are too poor for comparison. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Superfamily Cypridacea Family Beecherellidae Ulrich Genus Krausella Ulrich Emended description (Bassler, 1934, p. 38). — "Similar to Beecherella, except that the valves are more unequal, the left overlapping the right both dorsally and ventrally, while but a single spine occurs, this being a prolongation of the posterior extremity of the smaller (right) valve." Genotype. — Krausella inaequalis Ulrich. Krausella rawsoni Roy, sp. nov. Description. — Subelliptical in outline. Both valves almost equally convex, left one a little larger, slightly overlapping the right all around except at its acuminate posterior extension. This extension, however, is very short, hardly perceptible with the unaided eye. Surface under high magnification appears marked with a few minute, thinly scattered pustules. Length 1.4 mm., height 0.6 mm. Remarks. — This species shows no close affinity to any described member of the genus from the Ordovician. Its almost equally convex valves and short DESCRIPTION OF FOSSILS 175 posterior extension of the right valve may alone serve as sufficient distinguishing characters. The specific name is in honor of the late Frederick H. Rawson, sponsor of the expedition. n * * Fig. 143. Krausella rawsoni Roy, sp. nov. F.M. No. P28883. Holotype. a, Right valve, b, Left valve. Both X 11. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Holotype.— F.M. No. P28883. Krausella cf. K. inaequalis Ulrich Remarks. — This form shows strong likeness to Krausella inaequalis Ulrich from the Black River (Plattville) of Illinois, except that it is a little more elongate □ Fig. 144. Krausella cf. K. inaequalis Ulrich. F.M. No. P28884. a, Right valve, b, Side view of right and left valves, showing overlapping. Both X V. and the shell is not so thick. Moreover, the left valve, though distinctly larger, does not overlap the right one as strongly. It may be a new species but inasmuch as there is only a single specimen for consideration and so many of its essential characters are similar to those of K. inaequalis, it can not be used as a type. Length 2.3 mm., height 1.1 mm. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Krausella sp. Description. — There are two valves, a right and a left, referable to this genus; they may or may not belong to the same individual. Left or larger valve well preserved; length 2.9 mm., height 1.9 mm. Subelliptical, thick, and convex. Dorsal margin gently curved, ventral margin more or less straight, anterior and posterior ends rounded, having similar outlines. Right valve damaged along postero-ventral edge; length 2.9 mm., height 1.4 mm. There is indication of its posterior extension but it is broken and its exact nature cannot be ascertained. 176 ORDOVICIAN FOSSILS OF BAFFIN LAND The left valve is unlike any described species of the genus but since the right valve is damaged and the two valves may not belong to the same individual it would hardly serve any useful purpose to attempt to give this form specific identification. Fig. 145. Krausella sp. F.M. No. P28885. a, Right valve, b, Left valve. Both X 5. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. Family Bairdiidae Lieneklaus Genus Bythocypris Brady Emended description (Bassler, 1934, p. 39). — "Shell smooth, reniform, ovate or elliptical ; left valve larger than the right, overlapping it usually on both the dorsal and ventral margins; dorsal margin convex, the ventral edge straighter, sometimes slightly concave." Genotype. — Bythocypris reniformis Brady. Bythocypris aff. B. cylindrica (Hall) Bythocypris cylindrica (Hall). See R. S. Bassler, Geol. Soc. Amer., Special Papers, 1, p. 226, 1934, for references to literature and synonyms. Remarks. — This form agrees very closely with Bythocypris cylindrica (Hall) except that the central third of the ventral slope is more strongly hollowed out than is the case with B. cylindrica. This may be an individual variation or again Fig. 146. Bythocypris aff. B. cylindrica (Hall). F.M. No. P28886. a, Right valve. b, Left valve. Both X 7. it may be a specific character. There is, however, only one specimen at hand, so that it is impossible to determine which of the two interpretations is applicable. B. cylindrica has been reported from the Trenton to the Richmond. Horizon and locality. — Richmond. Silliman's Fossil Mount, Frobisher Bay, Baffin Land. Collector. — Sharat K. Roy. SYNOPSIS OF FAUNA GEOLOGIC RANGES OF NORTH AMERICAN AND GREENLAND SPECIES ALLIED TO THOSE FROM SILLIMAN'S FOSSIL MOUNT *Indicates species of Utile or no correlation value INCERTAE SEDIS Species from Silliman's Fossil Mount Allied Species Black River Trenton Richmond Receptaculites sp. R. arcticus Etheridge ? Receptaculites (1) fieldi, sp. nov. Receptaculites sp. CORALS Streptelasma sp. I S. breve W. and S.(?) Streptelasma sp. II S. robuslum amplum Troedsson + Streptelasma sp. Ill S. corniculum Hall +* Favistella sp. Columnaria (Favistella) alveolata Goldfuss Plasmopora lambei Schuchert + Plasmopora patiersoni, sp. nov. P. lambei Schuchert + Calapoecia canadensis anticostiensis Billings + Halysites agglomeralijormis Whitfield i + Halysites cf. H. gracilis (Hall) + cystoid and crinoid Cheirocrinus sp. Carabocrinus sp. BRYOZOANS Prasopora sp. Batosloma sp. Atactoporella cf. A. schu- cherli Ulrich + Dianulites sp. D. petropolitanus Dybow- ski J Eridotrypa bassleri, sp. nov. E. simulatrix (Llrich) + Eridotrypa cf. E. aedalis minor (Ulrich) + * 177 178 ORDOVICIAN FOSSILS OF BAFFIN LAND BRACHIOPODS Species from Silliman's Fossil Mount Allied Species Black River Trenton Richmond Plectorthis inaequiconvexa, sp. nov. P. plicatella (Hall) ? P. plicatella trentonensis Foerste + * Platyslrophia magnisulcata, sp. nov. P. elegantula triplicata McEwan ? Skenidioides^t) sp. Hesperorthis interplicata, sp. nov. Orthis tricenaria Conrad + * Glyptorthis bellarugosa (Conrad) + * Austinella cooperi, sp. nov. A. scovillei Miller + Austinella(l) subcircularis, sp. nov. A. kankakensis (McChesney) + DalmaneUa diminutiva, sp. nov. D. cf. D. testudinaria (Dalman) ? ? Dalmanella sillimani, sp. D. rogala (Sardeson) i * i * D. corpulenta (Sardeson) + D. ignota (Sardeson) + DalmaneUa sp. Parastrophinella hemipli- cata minor, var. nov. P. hemiplicata (Hall) + + Rajinesquina pronis, sp. nov. R. declivis (James) + * Rajinesquina declivis sub- nutans, var. nov. R. declivis (James) + * Rajinesquina producti- jormis, sp. nov. Rajinesquina sp. Sowerbyella sp. Strophomena undulosa, sp. nov. S. trilobata (Owen) + Strophomena sp. I Strophomena sp. II Rhynchotrema capax arc- ticum, var. nov. R. capax (Conrad) + Rhynchotrema anticostiense breve, var. nov. R. anticostiense (Billings) + R. increbescens (Hall) + * Rhynchotrema sp. R. increbescens laticos- tatum (Winchell and Schuchert) + * Zygospira maynei, sp. nov. Z. recurvirostris (Hall) + * + * + * Cyclospira schucherti, sp. nov. C. bisulcata (Emmons) + * Cyclospira vokesi, sp. nov. C. schucherti, sp. nov. + * SYNOPSIS OF FAUNA PELECYPODS 179 Ctenodonta baffinensis Ulrich ? Ctenodonta cf . C. subnasuta Ulrich +* Ctenodonta ulrichi, sp. nov. GASTROPODS Lophospira cf. L. augustina minnesotensis Ulrich and Scofield ? + Lophospira sp. I Lophospira sp. II Hormotoma rotundivolvis, ]H.(?) major sp. nov. (Hall) V + Hormotoma sp. I Hormotoma sp. II Hormotoma sp. Ill EotomariaC!) robinsoni, sp. nov. E. canalifera Ulrich Maclurina manitobensis{1) (Whiteaves) + Maclurina cuneata(l) (Whitfield) + Maclurites crassus(?) (Ulrich & Scofield) + Maclurites(l) sp. Trochonema cf. T. umbili- catum (Hall) +* ? Trochonemail) sp. Holopea(7) sp. Hyolithes crowelli, sp. nov. Endoceras baffinense Foerste CEPHALOPODS Endoceras sp. I + Endoceras sp. II E. fulgur Billings Endoceras sp. Ill E. paliforme Miller + E. manitobense Foerste + Endoceras sp. IV Ephippiorthoceras sp. I Ephippiortkoceras sp. II Charactoceras schticherli Foerste C. plicatus (Whiteaves) C. rotundum Troedsson 180 ORDOVICIAN FOSSILS OF BAFFIN LAND CEPHALOPODS — continued Species from Silliman's Fossil Mount Allied Species Black River Trenton Richmond Actinoceras sp. Leurorthoceras{1) baffinense Foerste Kochoceras Iroedssoni, sp. nov. K. cuneiforme Troedsson X. sublentiforme Miller + Kochoceras sp. if. troedssoni, sp. nov. ! + Westenoceras greggi, sp. nov. W. deckeri Foerste + Winnipegoceras lalicurva- tum (Whiteaves) + Neumatocerasi?) lumidum (Schuchert) Cyrtogomphoceras baffinense Foerste + Cyrtogomphoceras furnishi, sp. nov. Cyrtogomphoceras sp. I Cyrtogomphoceras sp. II Diestoceras milleri, sp. nov. D. magister Foerste + TRILOBITES Harpes sp. ind. Ischyrotoma{t) raymondi, sp. nov. Remopleurides sp. Isotelus gigas latior, var. nov. 7. gigras DeKay Isotelus cf. J. iowensis (Owen) + 7. consimilis Billings Illaenus baffinlandicus, sp. 7. groenlandicus Troedsson + nov. 7. americanus (Billings) +* Illaenus punclalus, sp. nov. 7. angusticollis Billings + * 7. groenlandicus Troedsson + Illaenus cf. 7. groenlandicus Troedsson + Illaenus sp. ind. Bumastus sp. ind. Encrinurus sp. ind. 72. rarus (Walcott) + * Calymene croneisi, sp. nov. C. senaria Conrad +* Calymene macmillani, sp. nov. C. croneisi, sp. nov. Ceraurus cf. C. horridus Troedsson + SYNOPSIS OF FAUNA TRILOBITES — continued 181 Species from Silliman's Fossil Mount Allied Species Black River Trenton Richmond Ceraurus sp. Ceraurinus icarus noduli- ferus, var. nov. + Pterygometopus callice- phalus brevis, var. nov. + * Pterygometopus sp. ind. I Pterygometopus sp. ind. II Calyptaulax sillimani, sp. nov. Eomonorachus deloi, sp. nov. OSTRACODS Leperditia cf . L. ulrichi Troedsson + Isochilina convexa, sp. nov. J. vaurealensis Twenhofel | + AparchitesC!) sp. Primitia cincinnatiensis (Miller) + Halliella jaynesi, sp. nov. | H. labiosa Ulrich + Eurychilina bassleri, sp. | ,-, ., , . TT1 . , B. mamlobensis ulnch nov. + Eurychilina sp. Krausella rawsoni, sp. nov. Krausella cf . K. inaequalis Ulrich +* Krausella sp. Bythocypris aff. B. cy/m-J rfn'co (Hall) + * + PREVIOUS COLLECTIONS FROM SILLIMAN'S FOSSIL MOUNT As referred to on page 44, three other collections besides the present one were made previously at Silliman's Fossil Mount. The first collection was made by Charles F. Hall during 1861-62. It was composed of two lots, of which one was collected from Silliman's Fossil Mount, the other from drift material on the northeast shore of Frobisher Bay and neighboring regions. The former was presented to the New York Lyceum of Natural History and the latter to Amherst College. The specimens from Silliman's Fossil Mount, consisting of seven species, were identified by R. P. Stevens (1863, p. 293) as follows: Maclurea magna (Lesueur), Endoceras proteijorme{1) (Hall), Orthoceras, Heliolites (sp. nov.), Heliopora (sp. nov.), Halysites catenulata (Fischer) (?), Receptacvlites (sp. nov.). None of these fossils was described or illustrated by Stevens, nor could they now be found for examination. It is, therefore, impossible to verify the accuracy of the identifications. As to the geological horizon indicated by these fossils, Stevens remarked (1863, p. 294) : "The fossils, without doubt, are all Lower Silurian. The Maclurea magna would place the limestone containing it on the horizon of the Chazy limestone of New York. The Halysites catenulata has been found in Canada in the Trenton beds, but in New York not lower than the Niagara limestone. The Endoceras proteiforme belongs to the Trenton limestone. The Receptaculites is unlike the several species of the Galena limestone of the West, or the R. occidentalis of Canada. Mr. Salter speaks of one found in the northern part of the American continent. This may be that species, or it may be a new one; which it was, we have no means of determining. The Orthocerata were but fragments, and so badly water-worn that the species could not be identified. "The specimens of corals were very perfect and beautiful, and unlike any figured by Prof. Hall in the Paleontology of New York. The Heliolites and Heliopora belong to the Niagara group, in New York, but in Canada they have been found in the Lower Silurian. For the identification of strata, corals are not always reliable. Whether these species are similar or identical with any in the Canadian collection, it was out of my power to determine. They are unlike any figured by Mr. I. W. Salter." It is apparent from the above statement that no particular horizon was determined other than that it was Lower Silurian. In fact it is scarcely possible to make any definite determination on the basis of such an inadequate collection. The drift fossils that were given to Amherst College were identified and described by B. K. Emerson (1879, pp. 575-583). They were later restudied by Schuchert (1914, pp. 470-471) and Bassler (1911, pp. 32-36). The result of the restudy is here quoted from Schuchert's paper (1914, pp. 470-471). 182 PREVIOUS COLLECTIONS 183 Three general horizons can be made out in southern Baffin Island, as follows: 1. ORDOVICIAN. Dense gray to cream colored or whitish limestones, in some places approaching lithographic stone. In other places or other horizons the material is a fine-grained, light pinkish, magnesian limestone, but in general the color of all these limestones is the opposite of dark. As a rule fossils are absent in them. In the purer and less dense limestones very small fossils occur, chiefly Ostracoda. The latter were first identified by Professor Emerson, and have been recently restudied by Doctor R. S. Bassler, with the following results: Leperditia canadensis Jonesl These two species seem to Bassler to be other forms Primitia muta Jones J than those indicated by Emerson. Primitia frobisheri Emerson= Eurychilina frobisheri. Beyrichia symmetrica Emerson= Drepanella symmetrica (related to the Richmondian B. richardsoni). Krausella cf. anticostiensis Jones. .) T , ,..-,, „ , ,, . , i ;• j • t } Identified by Bassler. Macrocypris cf. subcyhndnca Jones] Other associated fossils are a small Scenidium, sp. undet. (= Rhynchonella Emerson, p. 578), a small Plectambonites, sp. undet. (=Chonetes cf. striatella, p. 578), and fragments of undeterminable trilobites (= Emerson's Phacops and Asapkus). The fine-grained, light pink, magnesian limestone from Hall's Island has minute crystalline cavities that Emerson thought might be casts of Tentaculites. These the writer could not make out to be due to organisms. Other undeterminable fossils are Butkotrephis (p. 575, fig. 1) and Stictopora ramosa{1) (p. 577, may be burrows). On the basis of the Ostracoda, the only reliable fossils present, the horizon appears to be of Richmondian time, a formation of very wide distribution in North America. Bassler thinks the horizon and faunal realm represented are those of the English Head formation so well developed on the Island of Anticosti, Gulf of St. Lawrence. 2. ORDOVICIAN. Black, impure, thin-bedded, fine-grained limestones and black limy shales that weather yellowish white, with scattered small fossils as follows: Climacograptus bicornis (Hall). Common at French Head in Cyrus Field Bay and in Fox Land on western Baffin Island. (Also called Diplograptus dentatus by Emerson, p. 576.) Leptobolus lepis Hall (=Lingula curta, p. 578). Cyclora parvula (Hall) (=Cyclonema bilix, p. 578). "Endoceras proteijorme Hall" (p. 579). Not seen by the writer. "Orthoceras laqueatum?" (p. 579). Too poor and fragmentary to make out even the genus. Conularia trentonensis Hall (p. 578). A small fragment of a Conularia is present. Triarthrus beckii Green. Common in fragments. It is probable that the Colling- wood T. magnificus Twenhofel is also present (the tails are labeled Calymene senaria by Emerson, p. 582). Cyphaspis{1) frobisheri Emerson (p. 583, fig. 11). Based on a free cheek; the genus is not determinable. Ampyx{t) (Emerson's trilobite sp., p. 583, fig. 10). Leperditia alta (Conrad). This is not Conrad's Silurian species but appears to be a new form of Leperditia. 184 ORDOVICIAN FOSSILS OF BAFFIN LAND This horizon, on the basis of the above fossils and the further fact that Basilicus cana- densis (=Asaphus canadensis Chapman) occurs not far to the south at Cape Chidley, Labrador, seems to correlate with the Collingwood formation of Ontario. The same black shale is also present at Countess Warwick Sound, Blunt Peninsula, and probably as well at the head of Frobisher Bay. 3. SILURIAN. Gray, fine-grained dolomites of Rescue Harbor, Cyrus Field Bay, have Orthis cf. davidsoni, Halysites calenularia, and a pentamerid, probably the same as the next species. Farther west in Frobisher Bay in the identical dolomite occurs Conchidium nysius tenuicostatum (Hall), a form first described from the Falls of the Ohio. The Cyathophyllum pickthorni identified by Emerson (p. 577) are too poor to determine. This horizon is well up in the Silurian, probably in the lower Lockport, and about the horizon of the Louisville as developed at Louisville, Kentucky. Of these fossils only the first group, consisting mostly of ostracods which Schuchert believes to represent the Richmondian time, may have come from Silliman's Fossil Mount. At least they show a very close relationship with the ostracods described in this paper. The other two which, according to Schuchert, are the equivalent of the Collingwood (middle Ordovician) of Ontario and of the Louisville (Niagaran) as developed at Louisville, Kentucky, have apparently come from other sources and may not be considered here. The second collection, consisting of twenty-six specimens, was brought to this country by Mr. G. Cromer of Boston in 1896. The specimens were believed to have been collected by the Eskimos at the head of Frobisher Bay (Silliman's Fossil Mount) but the circumstances under which Mr. Cromer secured them are not known. Dr. R. P. Whitfield, to whom the specimens were entrusted, found fourteen species among them. They are as follows (Whitfield, 1900, p. 21) : Small Zaphrentis or Slreptelasma, sp.(?) Murchisonia (Lophospira) tricarinala Hall,sp. Orthis (Dalmanella) tesludinaria Dalman, sp. =M. milleri Hall Orthis (Plectorthis) jamesi Hall Helicotoma planvlata, or an undescribed sp. Cyclospira bisulcata Emmons, sp. BeUerophon, sp. undescribed, nearest to B. Strophomena planumbona Hall lindsleyi Safford Cyclospira, undescribed sp., plicated Oncoceras plebium Hall Rhynchonella increbescens Hall, not R. capax Trochoceras, sp. undet. Conrad Trocholites, sp. undet. Tellinomya alta Hall As to the stratigraphical conclusion, Whitfield stated (1900, pp. 21-22): "The geological horizon indicated by the group of specimens would be lower Trenton. The specimens are from calcareous clay and are finely weathered, indicating a locality where fine collections of fossils might be obtained with little trouble. The specimens have been collected from the surface and are mostly of small size and imperfect, so much so that those representing unde- scribed forms are too poor for description and illustration, though sufficient to determine the geological position." The above specimens are now lost; at least all efforts to locate them have failed. It appears, however, almost certain (to judge from the characteristics of PREVIOUS COLLECTIONS 185 the specimens) that they were collected from Silliman's Fossil Mount, but that they represent the lower Trenton is not in agreement with the studies made on the Ordovician in comparatively recent times. Apparently Whitfield based his conclusion on the similarity of the fauna to the Trenton (a method not infrequently practiced in his time), rather than on close, specific identification. But inasmuch as the specimens are not available it will serve little purpose to further discuss the subject. The third collection, which is by far the largest and most important of all previous collections made at Silliman's Fossil Mount, was collected in 1897 by five members (Messrs. J. N. Carpender, R. W. Porter, A. V. Shaw, A. H. White and F. G. Goodridge) of the Seventh Peary Arctic Expedition. The entire col- lection, the greater part 1 of which is now in the collections of the United States National Museum, was placed at the disposal of Dr. Charles Schuchert for study. The results of his studies were afterwards published (Schuchert, 1900). He described seventy-one species, of which sixty-five were named specifically. They are: Receptaculiles oweni Hall= Receplaculites arc- ticus Etheridge? Ischadiles iowaensis (Owen) Halysites catenulatus gracilis (Hall) LyeUia affinis (Billings) Plasmopora lambii, sp. nov.= (in part) Plas- mopora paitersoni Roy Calapoecia canadensis Billings Strepielasma corniculum Hall Porocrinus shawi, sp. nov. Lichenocrinus affinis Miller Crepipora, sp. undet. Orthis tricenaria Conrad= Hesperorthis inter- plicata Roy Orthis (DalmaneUa) tesludinaria (Dalman)= Dalmanella sillimani Roy Orthis (Plectorthis) plicateUa Hall= Austinella cooperi Roy Orthis (HeberteUa) borealis (Billings) =Pkc- torlhis inaequiconvexa Roy Orthis {HeberteUa) bellarugosa (Conrad) Orthis (Dinorlhis) meedsi Winchell and Schu- chert Orthis (Dinorlhis) meedsi arctica, var. nov. Platystrophia biforata (Schlotheim) =PJa/j/- strophia magnisulcata Roy Parastrophia hemiplicata Hall= Parastrophia hemiplicala minor Roy Rhyncholrema inaequivalvis (Castelnau) Ctenodonta subnasuta Ulrich? Ctenodonta frobisherensis, sp. nov. Ctenodonta carpenderi, sp. nov. Ctenodonta baffinensis, sp. nov. Modiolodon arctica, sp. nov. Whiteavesia symmetricus, sp. nov. Cyrtodonta sillimanensis, sp. nov. Cyrtodonta gibbera Ulrich, var. Vanuxemia abrupta Ulrich Vanuxemia baffinensis, sp. nov. Whitella arcticus, sp. nov. Saffordia modesta Ulrich Protowarthia pervolutus Ulrich and Scofield Tetranola obsoleta Ulrich and Scofield Kokenia costalis Ulrich and Scofield Bellerophon similis Ulrich and Scofield Lophospira spironema Ulrich and Scofield Liospira americana (Billings) Clathrospira conica Ulrich and Scofield=(in part) Eotomariail) robinsoni Roy SeelyaO) ulrichi, sp. nov. HelicotomaC!) larvata Salter Maclurina manilobensis (Whiteaves) Maclurina cuneata (Whitfield) Maclurea crassa Ulrich and Scofield Trochonema umbilicatum (Hall) Trochonema (Eunema) robbinsi Ulrich and Scofield Holopea arctica, sp. nov. TrochusC!), sp. undet. Fusispira inflata (Meek and Worthen) Fusispira nobilis Ulrich and Scofield Cameroceras proteijorme (Hall) = Endoceras baffinense Foerste 1 The remainder of the collection is in the American Museum of Natural History. 186 ORDOVICIAN FOSSILS OF BAFFIN LAND Orthoceras olorus baffinensis, var. nov.= Oncoceras arclicum, sp. nov.= Beloitoceras Spyroceras baffinense (Schuchert) arclicum (Schuchert) Orthoceras bilineatum Hall Poterioceras, sp. undet.= Diestoceras schu- Orthoceras porteri, sp. nov.= Spyroceras por- cherti Foerste teri ( Schuchert) Eurystomttes plicatus Whiteaves= Characto- ,_ , , ., . ,,. ceras schucherti Foerste Orthoceras scalanformis sp. nov.= Ktono- Bthis H Ulrich ceras scalanforme (Schuchert) D . ... ^, , . Frvmitia or Kloedenia Cyrtoceras manitobense Whiteaves= Tftufeo- Krause u a , two new species ceras ornatum Troedsson ^-^ mgilans (Meek and Worthen) Cyrtoceras cornulum, sp. nov.= Beloitoceras{1) niaenus crassicauda americanus (Billings) cornulum (Schuchert) Isotelus gigas DeKay Cyrtoceras baffinensis, sp. nov.= Beloitoceras Dalmanites {Pterygometopus) goodridgi, sp. baffinense (Schuchert) nov. Clinoceras exiguum (Billings) Ceraurus pleurexanlhemus Green Based on the studies of the above fauna Schuchert concluded (1900, p. 152) : "The foregoing list shows that at present there are 72 [71] species known from this locality, and of these 28 are restricted to it. There are, therefore, 54 species which are common to other localities, a goodly number with which to make safe correlations. Of these 54 species, 41, or 57 per cent of the known fauna, are also found in the region of Minnesota, Wisconsin, and Iowa, while 17 are known to occur in New York and Ottawa. "On comparing the 54 widely distributed species with those from definite stages in Minnesota, it is seen that 10 are also found in Birdseye (=Lowville), 17 in the Black River, 38, or about 70 per cent, in the Galena, the direct equiva- lent of the New York Trenton, and 11 in the Cincinnatian group. "From these figures it is evident that the stage of Silliman's Fossil Mount belongs in the Galena, and that the fauna is more intimately related to that of the Minnesota region than to the Trenton of New York. When the New York Trenton fauna is restudied in the light of recent researches in Minnesota, how- ever, it will be shown that the two faunas have more in common than now appears. On the other hand, the lithological similarities of the Minnesota Galena and Silliman's Fossil Mount — light-colored shales predominating in both areas — may explain in large measure the close identity of these widely separated faunas." With regard to the general distribution of the fauna and to the presence of certain genera of corals which are definitely of younger age than the Trenton, Schuchert stated (1900, p. 175): "The Baffin Land fauna had an early intro- duction of Upper Silurian genera in the corals Halysites, Lyellia, and Plasmopora. In Manitoba similar conditions occur in the presence of Halysites, Favosites, and Diphyphyllum. Other Upper Silurian types do not appear to be present .... "The Trenton fauna of Baffin Land shows that the corals, brachiopods, gastropods, and trilobites have wide distribution, and are therefore less sensitive to the differing habitats apt to occur in widely separated regions. On the other hand, the cephalopods, and particularly the pelecypods, indicate a shorter geo- graphical range. The almost complete absence of Bryozoa in the Baffin Land PREVIOUS COLLECTIONS 187 Trenton contrasts strongly with the great development of these animals in Minnesota and elsewhere in the United States." In 1911 Dr. R. S. Bassler restudied the fauna and came to the following conclusions (1911, pp. 34-36) : "(1) It is improbable that Utica strata occur in the far north, since the only fossil noted of any value in making such a correlation is Triarthrus becki, which is now known to occur also in the oldest Trenton. Of course it is possible that an arm of the sea extended northward during Utica time and allowed the depo- sition of these particular strata. "(2) The Trenton age of the principal Ordovician deposits was determined by Schuchert by the percentage composition method. He found that of the 72 species known from the Silliman's Mount locality, 54 were common to other areas. Comparing these 54 with known horizons in Minnesota, it was found that 10 occur in the Lowville, 17 in the Black River, 38, or about 70 per cent, in the Trenton, and 11 in the Cincinnatian. This prevalence of Trenton species seemed to be a good indication of the presence of a single fauna of that particular age. However, this method of correlation is open to some objections and has often been the occasion of error. In this particular example, the fossils were derived from the debris of a considerable thickness of strata, and there is just as much if not more reason for believing that the Lowville, Black River, Trenton and Richmond rocks are actually present in the section as for assuming that only Trenton strata occur. The former view is strengthened by the unquestioned stratigraphy of areas further south and west. Ulrich's identification of recent collections made by Kindle in Alaska, has shown the occurrence of a Black River fauna followed by a coral fauna of Richmond age. In Manitoba and elsewhere in Canada, the early Trenton strata (Maclurea bed) are succeeded by the Earliest Silurian Richmond group. The same succession of Richmond strata upon Tren- ton or older rocks is present in various parts of the Rocky Mountain area of the United States, especially in the Big Horn Mountains, and even as far south as El Paso, Texas. The most prevalent zone of the Richmond group contains numerous corals of Silurian genera, Halysites, Lyellia, Plasmopora, and Cala- poecia. This is the same fauna noted on other pages of this work as present in the upper Lyckholm and Borkholm limestone of Baltic Russia. The 11 'Cin- cinnatian' species recorded by Schuchert from Silliman's Mount includes this same coral fauna, and it therefore seems certain that the Richmond group is represented in the section. The Richmond age of these corals was further evidenced by the fact that two very characteristic brachiopods, a variety of Platystrophia acutilirata and of Plectambonites sericeus came to light when I carefully searched a fragment of limestone adhering to one of the corals. This particular variety of Plectambonites is highly characteristic of the Richmond in America and Europe. It is distinguished by the occurrence of small teeth along the edge of the cardinal area of the dorsal valve. "The 38 strictly Trenton species, when compared with Minnesota faunas, are found to be characteristic of the Clitamboyiites, Nematopora, and Maclurea 188 ORDOVICIAN FOSSILS OF BAFFIN LAND beds of the Minnesota-Iowa composite section, or, in other words, probably occur in strata equivalent to the early Trenton (Stewartville and Prosser lime- stone) of the more southern area. The species ofFusispira, Maclurea, Maclurina, Receptaculites, Ischadites, and other genera listed by Schuchert as occurring in the Silliman's Mount fauna, and elsewhere only in the Minnesota Trenton, are associated with a gray, fine grained rock which, when carefully prepared, fur- nished a small fauna of Ostracoda including a Leperditia with Trenton affinities, but more especially the two bryozoans characteristic of the Nematopora bed in Minnesota, Nematopora ovalis Ulrich and Pachydictya pumila Ulrich. "Concerning the occurrence of Lowville limestone at Silliman's Fossil Mount, the evidence is not as conclusive as that for the Lower Trenton and Richmond divisions, indeed, it is probable that only the equivalent of the Decorah shale is present since the 10 Lowville species listed by Schuchert occur also in that formation. Schuchert's list, however, shows enough characteristic Black River species to make it certain that some part of this group is represented in the section. Many of the specimens of these particular species show a slight difference in color and preservation from the Trenton forms discussed above. The more recent study of this Baffin Land fauna disclosed the presence of at least six species of Bryozoa, so that the remarks above concerning the practical absence of these forms are less to the point. Indeed, it is believed that the bryozoans are present, but because of their uninteresting aspect to the usual student, were not collected. "Summing up, it seems probable from Schuchert's results, combined with the more detailed correlations of the present paper, that the geologic section at Baffin Land consists of Black River strata resting upon the old crystalline rocks, followed by an early Trenton formation equivalent to the Stewartville and Pros- ser limestones of Minnesota, and this in turn succeeded unconformably by the widespread coral zone of the Richmond group." Schuchert agreed with Bassler's interpretation and said (1914, p. 472) : "In conclusion, the writer agrees with Bassler that there are at least two Ordovician horizons represented at Silliman's Fossil Mount, namely, (1) a lower one con- taining the bulk of the fauna and equivalent to the Lower Trenton of Minnesota, and (2) an upper fauna here essentially made up of corals and the equivalent of that of Middle Richmond time. It is probable that the Black River equivalent is also present at the Mount, though less well exposed and on or below the debris- covered lower slope of the Mount." Since the restudy of this fauna, considerable work has been done in the arctic Ordovician and in the light of the progress made Schuchert now holds that no Black River or Trenton time is present in the Silliman's Fossil Mount but that all is of late Ordovician or Richmondian time (personal conversation, September 19, 1940). Bassler also now favors the Richmond age for the entire formation. AGE OF SILLIMAN'S FOSSIL MOUNT The question at issue is whether the fossils from Silliman's Fossil Mount represent the Mohawkian (Black River and Trenton) or the Richmond or both. For an answer to or indeed for a clear understanding of the problem, it would be necessary to state the factors which have given rise to it. These are: (1) The fossils were not found in stratigraphic sequence except for a few gastropods belonging to the genera Maclurina and Maclurites, and a single cephalopod, Westenoceras greggi, which were collected in situ on the top of the mount; (2) the fossils suggest both Mohawkian and Richmondian age; and (3) correlation of arctic Ordovician faunas has largely been based on general similarities of faunas rather than on precise identifications of individual species. Regarding the first factor, little can be said that would alleviate the diffi- culty. It is pertinent to mention, however, that no apparent lithologic difference is discernible among the beds of the mount. This may be verified in the exposure on the section behind the first front ridge (fig. 20, p. 41). The chemical analyses of the rocks (p. 43) also indicate that no significant difference exists among them other than what would be accounted for by slight changes in the condition in sedimentation. If there were two formations with several inter- vening ones missing, such as would be the case if a Richmond equivalent were laid upon a Trenton, some indication of the time that elapsed between the deposition of the two formations would be expected. No such record of an erosion interval is visible. It is, however, not implied that the absence of an erosional unconformity and the lack of lithological or significant chemical change prove definitely that the beds are of the same age, but this evidence nevertheless favors such an interpretation. The second and third factors mentioned above are inter-related and it is desirable to treat them together. Much of the uncertainty that now exists regarding the age of the fauna of Silliman's Fossil Mount and of certain other closely related Ordovician faunas described in comparatively recent times from arctic America, central Canada, northern Alaska, and western United States, could be eliminated if the age of the fauna of the Red River formation of southern Manitoba were definitely settled. The latter fauna is strikingly similar not only to the fauna of Silliman's Fossil Mount but also to those from other localities cited above. The Red River fauna, therefore, as has already been indicated by Foerste (1929, p. 138), promises "to serve as a key in the solution of uncertainties in stratigraphy presented by those areas in which the opportunities for determin- ing the stratigraphic sequence of the different faunas are less favorable." The Red River formation occurs on the west shore of and on the island in Lake Winnipeg in southern Manitoba, and in the adjacent part of the Red River Valley. D. B. Dowling (1900) divides the Ordovician beds of this area into the following formations: 189 190 ORDOVICIAN FOSSILS OF BAFFIN LAND Stony Mountain formation [Upper Mottled limestone [= Selkirk limestone of Foerste] [Red River formation of FoersteK Cat Head limestone [Lower Mottled limestone [= Dog Head limestone of Foerste] Winnipeg sandstone As indicated above, Foerste (1928c, p. 26) proposed the names Selkirk limestone for the Upper Mottled limestone, and Dog Head limestone for the Lower Mottled limestone. He also proposed the name Red River formation to include all three strata, Selkirk, Cat Head and Dog Head. These changes in nomenclature have gained adoption and the original names have become obsolete. The Stony Mountain formation is composed of shales and limestones total- ing about 100 feet. From these beds Dowling (1900, pp. 48F-53F) has listed sixty-two species, the majority of which occur in, or are restricted to, the accepted Richmondian strata. According to Dowling (p. 47F) the upper part of the Stony Mountain formation "is referable to the Richmond group of Minne- sota," and the lower beds "are similar to the Utica of the Cincinnati formation." More recently, W. H. Twenhofel correlated the Stony Mountain formation with zones 3, 4 and 5 of the Vaureal member of the Richmond group as exposed on Anticosti Island. Thus there seems to be no question regarding the Richmond age of the Stony Mountain formation. The present problem is: What is the age of the underlying limestones, collectively called the Red River formation, and of the Winnipeg sandstone? Should they be regarded as Mohawkian or Richmondian? The Winnipeg sandstone forms the basal member of the sequence. Of the twelve fossils described from it, four are common to the overlying beds. Dowling thought that the sandstone represented the upper part of the Black River for- mation but he was not certain. The fossils give no definite information. The sandstone may be the initial deposit of and of the same age as the Red River formation. As to the Red River formation, J. B. Tyrrell (1892) correlated it with the Trenton. J. F. Whiteaves maintained the same correlation except that he thought that the formation holds "several fossils elsewhere supposed to be restricted to the Hudson River group." (1897, p. 135.) He added that the rela- tionship of the Red River fauna was closer to that of the northern part of the Mississippi Valley than that of New York, southern Ontario and other eastern areas. D. B. Dowling brought together all the information available at that time regarding the Red River fauna and correlated the Selkirk (Upper Mot- tled) limestone, the Cat Head limestone, and the Dog Head (Lower Mottled) limestone with the Maclurea beds, Fusispira and Nematopora beds, 1 and Clitam- bonites beds 1 respectively (Dowling, 1900, p. 35F). The above correlations remained virtually unquestioned for many years. The first suggestion that the Red River formation may be younger than the Trenton came from R. S. Bassler in 1915. In his list of Red River cephalopods he stated (1915, p. 1458): "This list includes the species from the Cat Head and associated formations in Mani- 1 Divisions of the Trenton group in Minnesota. AGE OF SILLIMAN'S FOSSIL MOUNT 191 toba. Although recorded as of Mohawkian age by Whiteaves, it is probable that many of them were derived from Richmond strata." Unfortunately, Bassler did not specify in his list any particular species which he considered to be of Rich- mond age. Some years later, Foerste became interested in the age of the Red River formation and in the correlation of its different members with their equivalents in the Arctic and in the United States. A great deal of our knowledge of the arctic Ordovician faunas, the cephalopods in particular, is due to his labors. Speaking of his interest in the Red River fauna, he stated (1932, p. 53) : "The Red River formation and its equivalent is one of the most remarkable of known Paleozoic formations on account of its enormous extension in a north and south direction, its range from northwestern Greenland to south-central Oklahoma equaling more than 3,100 miles, and extending from the most northern fossilifer- ous areas known in the Arctic to the southern part of the Temperate zone. The most southern outcrop of this Arctic invasion is in the El Paso area, in the extreme western part of Texas." The first indication that Foerste suspected that the Red River formation might be of later age than Trenton is found in his statement (Foerste and Savage, 1927, p. 10): "... a considerable part of the genera found in the Winnipeg limestone [Red River formation] continue into strata whose Richmond age is unquestioned but which are located in other areas." In 1928, basing his state- ment on his studies of the cephalopods of Putnam Highland, southwestern Baffin Land, and on the studies of other elements of the faunas of equivalent age from elsewhere, he stated (1928, p. 32) : "Our present knowledge of the cepha- lopods and corals appears to favor the Richmond age of the entire Red River formation, as exposed in southern Manitoba, and of the combined Shammattawa- Nelson section, as exposed in the area southwest of Hudson Bay." In 1929 Foerste expressed his opinion more clearly, as follows (1929a, p. 146): "The present problem is whether the Red River formation shall be regarded as of Trenton or of Richmond age. The answer will depend on the point of view of the investigator. Prevalence of a general Trenton facies suggests its Trenton age. The introduction of an important number of characteristic Richmond genera and species suggests its reference to the Richmond. The present writer favors the latter procedure." Again in 1929, in a discussion of the stratigraphic position of the Red River formation, he stated (1929, p. 47): "If the number of species having Mohawkian affinities be compared with those having Rich- mond affinities, the former will have the majority, and the Red River forma- tion will then be regarded as Mohawkian — more specifically as Trenton. On the contrary, if the first considerable invasion of species having Richmond affin- ities into an otherwise Mohawkian fauna be regarded as indicating contempo- raneity with Richmond strata, then the Red River fauna will be regarded as of early Richmond age. It is the second method of solution which here is adopted. Hence the lower Richmond age of the Red River fauna is accepted." In a later paper, however, he indicated that the Red River formation might be an inter- 192 ORDOVICIAN FOSSILS OF BAFFIN LAND mediate horizon, as can be deduced from the following statement (1932, p. 56) : "While none of these Black River precursors 1 appear strictly identical with the Richmond faunas exposed in the Big Hill member of the Richmond, it is evident that intermediate forms must have occurred somewhere in those formations which intervene between the Black River and the Richmond, and that these inter- mediate forms are not known at present from any source, unless the Red River represent such an intermediate horizon." A. K. Miller, in his discussion of the age of the basal or Lander sandstone member of the Bighorn formation, which is considered to be of the same age as the Red River formation, concluded (1930, pp. 203-204) : "From the preceding discussion it is evident that although Black River and Trenton affinities are present in the fauna of the Lander sandstone, a considerable number of forms with Richmond affinities also occur here. Furthermore, although superficially the majority of the fossils would seem to support the traditional belief in a Mohawkian age, a critical examination of the available evidence seems to belittle the Mohawkian affinities. Also, since the Richmond fauna is a recurring Mo- hawkian fauna, Mohawkian forms should be expected in the Richmond, but the reverse would be difficult to explain. These facts have led the writer to the con- clusion that the fauna of the Lander sandstone is of Richmond age." G. Marshall Kay, on the other hand, favors Trenton age for the Red River formation. "The facts contributed in this paper lend support to a view that the Red River formation may be of Trenton age; and it is possible that the beds represent both the Prosser and Stewartville, the boreal element appearing in Manitoba in Prosser time, not becoming preponderant farther south until the Stewartville." (Kay, 1935, p. 589.) He, however, makes this reservation (p. 588) : "One must conclude that the evidence is still not sufficient to demon- strate the age of the Red River unequivocally. Though the formation has a close faunal resemblance to the Stewartville, the species in many cases are distinct, and it may be added that forms from supposed Red River equivalents in the Arctic have also been specifically distinguished. There are a few forms that suggest Cincinnatian age, and they may prove to be the most significant, but there are many more that characterize known Trenton formations." Kay's main contention, favoring Trenton rather than Richmond age for the Red River formation, seems to be based on certain faunal elements which have been regarded as evidence of Richmond age but which, or rather the like of which, also occur in the Trenton. The elements under consideration with Richmond affinities are four genera of cephalopods, Billingsites, Ephippiorthoceras, Charactoceras, and Cyclendoceras; one coral, Halysites gracilis (Hall), and three brachiopods, Lep- taena unicostata (Meek and Worthen), Rhynchotrema capax (Conrad), and Dinor- this subquadrata (Hall). Of the cephalopods, Kay cites one or more specific examples from the Trenton for each of the genera except Billingsites (none, how- ever, is conspecific with a Red River species) and states (1935, p. 588) : "Thus, of 1 Certain corals described under the names Calapoecia canadensis, Halysites catenularia var. quebecensis, and Columnaria rugosa, from the Black River formation at Blue Point, north of Roberval, on the west side of Lake St. John, Quebec. AGE OF SILLIMAN'S FOSSIL MOUNT 193 the cephalopods, Billingsites seems to be the single genus that is strongly sug- gestive of a post-Trenton age for the Red River formation." Billingsites, how- ever, is not the only genus strongly suggestive of a post-Trenton age. The genus Huronia, represented by H. occidentalis Foerste, occurs in the Red River formation and is equally suggestive of a post-Trenton age. As to the occurrence of Halysites gracilis (Hall) in the Stewartville, it may be reiterated, for the subject has been discussed at length on page 77, that the different species of Halysites, particularly those that are closely allied, are diffi- cult to differentiate. Whether H. gracilis from the Stewartville is conspecific with the Red River species is not definitely known, for no comparative studies of the two forms have ever been made. But even assuming that the two species are conspecific, there remain Calapoecia canadensis Billings, Columnaria stokesi (Edwards and Haime) and Palaeofavosites prolificus (Billings) to be accounted for. Each of these three species suggests affinities with the Richmond and all occur in the Red River formation, but none is represented in the Stewartville. Of the brachiopods, Kay states (1935, p. 588): "Leptaena unicosta (Meek and Worthen) seems of Cincinnatian affinity, but the Rhynchotrema sp. in the Stewartville is more like R. capax (Conrad) than any other Trenton species; and Dinorthis subquadrata (Hall) is closely similar to the species in the Dubuque dolomite and to D. iphigenia (Billings) of the Lower Cobourg." It is evident from the above statement that of the two brachiopods from the Stewartville, neither is conspecific with a Red River species — they are only closely allied. It may be brought to attention here that, in addition to the brachiopods referred to above, there are several other important Red River species of post-Trenton age, none of which is known from the Stewartville. These are: Stroplieodonta leda (Billings), Dinorthis proavita (Winchell and Schuchert), Platystrophia crassa (Jones), and Rhynchotrema anticostiense (Billings). Other elements of the Red River fauna with Richmond affinities, not known in the Stewartville, are Nidulites gregarius (Billings), Conularia asperata Billings, and Onehometopus susae (Whitfield). From the preceding paragraphs it is apparent that the evidences that Kay has brought forward in support of the Trenton age of the Red River formation is based not on conspecific forms but on a few closely allied species and on certain identical genera occurring in the Stewartville and the Red River formation. Precise identification of stratigraphic units demands precise identification of individual species. Hence, any attempt to correlate strata deposited in distinct basins by means of specific resemblances alone is subject to serious error. Like- wise, there is danger in correlation based on the presence of congeneric forms, for many genera have long vertical range. That the Red River formation has a close faunal resemblance to the Stewartville is conceivable. Both faunas were originally of the same faunistic realm and the younger is likely to contain some "holdovers" from the older that are but slightly modified. Here the Red River fauna is regarded as younger, for it contains a considerable number of forms with Richmond affinities; the Stewartville does not. 194 ORDOVICIAN FOSSILS OF BAFFIN LAND To get a comprehensive understanding of the age of the fauna in the Red River formation it would be necessary to examine also the faunas which are regarded to be of equivalent age and which have been studied in comparatively recent times. Such an examination will bring to light those species which have not been recorded from the Red River formation but have been found elsewhere, and vice versa. The general distribution of the faunas of equivalent age has been mentioned above. More specifically, these faunas occur in northwestern Green- land, east-central and southern Ellesmereland, North Devon Island, Well- ington Channel, Melville Island, North Somerset Island, Boothia Peninsula, King William Island, Igloolik Island, southeastern and southwestern Baffin Land, Southampton Island, Akpatok Island, southwest of Hudson Bay, Lake Timis- kaming, Great Slave Lake, southern British Columbia, northern half of Alaska, western Wyoming, southwestern South Dakota, central Colorado, and parts of Montana, Idaho, Utah, Oklahoma, New Mexico, and Texas. Of these localities only the more important ones — those from which com- paratively large collections have been made — will be considered. Only those elements of the faunas with unquestionable Richmond affinities will be discussed, for the significant feature of the faunas under consideration is not the presence of a large number of species with Mohawkian affinities but the introduction of younger elements with strong Richmond affinities. It should be pointed out, however, that the Mohawkian fossils in the Red River formation are not nearly as common as was once believed. Miller lists twenty-five forms with Mohawkian affinities from the Lander sandstone (equivalent to the Red River formation) of Wyoming, of which only two, Spyroceras olorus (Hall) and Beloitoceras plebium (Hall), were identified; the remaining twenty-three of his specific identifications were qualified with "?," "cf.," or "aff." This suggests that typical Mohawkian forms are rare and that the great majority of them have undergone modifications. The same is true of the present collection. Not a single form was found to be conspecific with a known Mohawkian species. When compared with specimens of definite Mohawkian age, the Silliman's Fossil Mount forms showed slight but distinct differences. Foerste, in speaking of Dowling's list of fossils (Dowling, 1900, pp. 48F-53F) from the Red River formation, remarked (1928, p. 32): "In this list, various species have been identified with characteristic Trenton and Black River forms, in my opinion erroneously." At the time the identifications were made, the mere presence of a large Receptaculites or a large Maclurina was considered sufficient evidence for Mohawkian age. In other words, identifications usually were made on preconceived notions as to the age of the fossils, in conse- quence of which slight specific differences that might have existed were over- looked. This has been very clearly stated by Schuchert: 1 "In 1900, no one knew these 'sunflower corals' in other than middle Ordovician formations, but in recent years they have been shown to occur also plentifully in late Ordovician faunas from Manitoba to northwest Greenland. This increase of knowledge, together with an extension of the range of the corals and of the gastropod, 1 Quoted by permission from unpublished manuscript. AGE OF SILLIMAN S FOSSIL MOUNT 195 Maclurina manitobensis, has led to the discovery that the Richmondian faunas are of the widest distribution in Arctic America. This view is further strength- ened by the cephalopods." Foerste (1924, p. 17) quotes Ulrich as stating that "the Richmond of Alaska and the western states contains a species of Recepta- culites so similar to Receptaculites oweni that it has been distinguished only recently." With regard to Maclurina, he further quotes Ulrich as stating that "the Stewartville member of the Trenton contains fossils that have been identi- fied with Manitoban fossils (notably Maclurina manitobensis and Receptaculites oweni), but are not precisely similar." Several specimens of Maclurites and Maclurina in the present collection were found in situ at the top of the Fossil Mount, whereas all the cephalopods, except Westenoceras greggi, and all the corals having distinct Richmond affinities were collected from talus slopes which were obviously the result of disintegration of lower beds. It is evident, therefore, that the gastropods Maclurites and Maclurina are no older than the other groups. Thus the following statements seem to be invalid: "The Baffin Land fauna had an early introduction of Upper Silurian (Richmond) genera in the corals Holy- sites, Lyellia, and Plasmopora" (Schuchert, 1900, p. 175); and "The geologic section at Baffin Land consists of Black River strata resting upon the old crystal- line rocks, followed by an early Trenton formation equivalent to the Stewartville and Prosser limestones of Minnesota, and this in turn succeeded unconformably by the widespread coral zone of the Richmond group." (Bassler, 1911, p. 36.) LIST OF SPECIES REGARDED AS OF RICHMOND AGE M=Red River formation, southern Manitoba; B=Frobisher Bay beds, Baffin Land; G=Cape Calhoun beds, Greenland; and W= Lander sandstone, Wyoming. Nidulites gregarius (Billings) M Streptelasma rusticum (Billings) G Streptelasma robustum Whiteaves M, B? G, W Columnaria slokesi (Edwards and Haime) M, G Paleofavosites prolificus (Billings) M Calapoecia canadensis Billings M Calapoecia canadensis ungava Cox G Calapoecia canadensis anticostiensis Billings B, G Calapoecia canadensis anticostiensis f. arctica Troedsson G Plasmopora lambei Schuchert B, G Plasmopora pattersoni Roy B Lyellia affinis Billings B Halysites gracilis (Hall) M, B, G, W Halysites agglomeratiformis Whitfield B, G Syringopora conspirata Troedsson G Plilodiclya flagellum Nicholson G Monticulipora parasitica plana Ulrich G Rhombotrypa subquadrata Ulrich G Dinorthis subquadrata (Hall) M, W? Dinorthis proavita (Winchell and Schuchert) M Platystrophia crassa (Jones) M Austinella cooperi Roy B 196 ORDOVICIAN FOSSILS OF BAFFIN LAND Rafinesquina lata Whiteaves G, W Strophomena fluctuosa Billings G Strophomena plandorsata (Winchell and Schuchert) G, W Leptaena unicostata (Meek and Worthen) M, G? Rhynchotrema capax (Conrad) M, B? G, W? Rhynchotrema anticostiensis (Billings) M, B, W? Maclurites acutus (Parks) G Conularia asperala Billings M Endoceras fulgur (Billings) B? W Billingsites costulatum (Whiteaves) M Charactoceras baeri (Meek and Worthen) G? Wilsonoceras mccharlesi (Whiteaves) M Apsidoceras elegans Troedsson G Huronia occidentalis Foerste M Homotelus gratiosus Raymond G Onchometopus susae (Whitfield) M Ceraurinus icarus (Billings) B? G Primitia cincinnatiensis (Miller) B The above list is taken from only four out of at least thirty localities and, therefore, is much short of the total number of species with Richmond affinities known from beds equivalent to the Red River formation. Moreover, the list does not include the numerous new species with Richmond affinities described in recent times, or the equally numerous forms that have been identified as closely allied to Richmond species. If all these species were considered, the total num- ber would be quadrupled at least. The question now may be asked : Where did they come from? Why are they not present in the Mohawkian of the Mississippi Valley or in the Mohawkian of New York, southern Ontario or other eastern areas? It would hardly be convincing to attempt to answer these questions by simply stating that they are but an early introduction of younger elements in an otherwise older or Mohawkian fauna. The number of Richmond species is far too large to favor such a conclusion. The inescapable answer is that the Red River fauna and its equivalents, which include the Silliman's Fossil Mount fauna, are post-Mohawkian, or of early Richmond age. The presence of Mohawkian forms, as has been mentioned previously, is due to the fact that the faunas under consideration are a recurring Mohawkian fauna. The recurrence may be explained by assuming that during Eden and Maysville times the Mohawkian forms retreated to northern waters where they existed until they replenished the Richmond seas which progressively spread southward from the Arctic over the northern half of Alaska, much of Canada, British Columbia, across west-central United States down to Texas. In general, this is true of the northern Richmond invasions. The Richmond faunas of southern origin invaded the continent by way of the Gulf of Mexico. Some of these southern faunas were "originally of northern origin, but during Eden and Maysville times gradually extended their ranges southward, so that when the southern Richmond invasion took place they were able to enter the Mississippi embayment, and progress as far north as Ohio, and later, southern AGE OF SILLIMAN S FOSSIL MOUNT 197 Canada." (Foerste, 1924, p. 45.) Based chiefly on the studies of Ulrich, Schuchert and Foerste, the last-named author has ably summarized the diastrophic changes which were responsible for the recurrence of Mohawkian fauna and the distri- bution of the Richmond faunas of both northern and southern origin, as follows: "During Black River and Trenton times the North American continent was apparently tilted so as to admit epicontinental seas, chiefly from the north. During Eden and Maysville times it appears to have been tilted in an opposite direction. Northward tilting brought in again the Black River and Trenton faunas during Richmond time. Of course, events were not altogether as simple as suggested by these statements. Epicontinental seas deriving their faunas from different sources were no doubt present on different parts of the continent at the same time. The invasions that extended over the wider areas were prob- ably due to tiltings that more or less excluded faunas from other directions. It is unlikely, for instance, that the major northern Richmond invasions were strictly contemporaneous with the major southern Richmond invasions. Although it is possible to determine their relative ages only where they overlap, their approximate age may be determined even when the strata are nowhere in contact." (Foerste, 1924, p. 46.) The above statements afford the basis to conclude clearly that the Silliman's Fossil Mount fauna and its equivalents are a recurring Mohawkian fauna of early Richmond age. The facts that the elements with Mohawkian affinities in these faunas are rarely conspecific with typical Mohawkian species and that these faunas contain a considerable number of unquestioned Richmondian forms are alone sufficient evidence to arrive at such a conclusion. That in a recurring fauna there should be a strong similarity of the major portion of its elements to the older forms is not only to be expected but is also in accord with our present conception of organic evolution. 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Notes on Ordovician Trilobites: Illaenidae from the Black River Limestone near Ottawa, Canada. Ann. Carnegie Mus., 4. Reed, F. R. C. 1905. The Classification of the Phacopidae. Geol. Mag., dec. 5, 2. 1927. Recent Work on the Phacopidae. Ibid., 64, Nos. 755 and 758. Roy, S. K. 1929. Columnar Structure in Limestone. Science, 70, No. 1806. 1932. Upper Canadian (Beekmantown) Drift Fossils from Labrador. Field Mus. Nat. Hist., Geol. Ser., 6, No. 2. 1937. The Grinnell Ice-cap. Ibid., 7, No. 1. 1937. The History and Petrography of Frobisher's "Gold Ore." Ibid., No. 2. 1938. Additional Notes on the Grinnell Ice-cap. Ibid., No. 4. RUEDEMANN, R. 1901. Trenton Conglomerate of Rysedorph Hill, Rensselaer Co., N. Y., and Its Fauna. Bull. N. Y. State Mus., 49. Safford, J. M. 1869. Geology of Tennessee. Salter, J. W. 1853. On Arctic Silurian Fossils. Quart. Jour., Geol. Soc. Lond., 9. 1859. Figures and Description of Canadian Organic Remains. Geol. Surv. Canada, dec. 1. 1864. A Monograph of British Trilobites. Paleont. Soc, 16. Sardeson, F. W. 1891-92(?) The Range and Distribution of the Lower Silurian Fauna of Minnesota with Descriptions of Some New Species. Bull. Minnesota Acad. Nat. Sci., 3. 1897. The Galena and Maquoketa Series. Part 3. Amer. Geol., 19. Savage, T. E. 1927. See Foerste, A. F. and Savage, T. E., 1927. and Van Tuyl, F. M. 1919. Geology and Stratigraphy of the Area of Paleozoic Rocks in the Vicinity of Hudson and James Bays. Bull. Geol. Soc. Amer., 30. Schmidt, Fr. 1881. Revision der ostbaltischen silurischen Trilobiten nebst geognostischer Ueber- sicht des ostbaltischen Silurgebiets. Abt. I. Phacopiden, Cheiruriden und Encrinu- riden. Mem. Acad. Imp. des Sci. de St. Petersburg, Vile serie, tome XXX, No. 1. Schuchert, C. 1893. See Winchell, N. H., 1893. 1895. See Winchell, N. H., 1895. 1897. A Synopsis of American Fossil Brachiopoda, Including Bibliography and Synonymy. Bull. U. S. Geol. Surv., 87. 1900. On the Lower Silurian (Trenton) Fauna of Baffin Land. Proc. U. S. Nat. Mus., 22, No. 1192. 1914. Notes on Arctic Paleozoic Fossils. Amer. Jour. Sci., 38, ser. 4. 204 OKDOVICIAN FOSSILS OF BAFFIN LAND and Cooper, G. A. 1932. Brachiopod Genera of the Suborders Orthoidea and Pentameroidea. Peabody Mus. Nat. Hist., 4, pt. 1. Scofield, W. H. 1897. See Ulrich, E. O. and Scofield, W. H., 1897. Shimer, H. W. 1910. See Grabau, W. A., 1910. Slocom, A. W. 1913. New Trilobites from the Maquoketa Beds of Fayette County, Iowa. Field Mus. Nat. Hist., Geol. Ser., 4, No. 3. Spivey, R. C. 1939. Ostracods from the Maquoketa Shale of Iowa. Jour. Paleont., 13, No. 2. Stevens, R. P. 1863. Report on the Geological and Mineralogical Specimens Collected by Mr. C. F. Hall in Frobisher Bay. Amer. Jour. Sci., 35, ser. 2, pp. 293-294. Sutherland, P. C. 1853. On the Geological and Glacial Phenomena of the Coasts of Davis' Strait and Baffin's Bay. Quart. Jour., Geol. Soc. Lond., 9. Teichert, C. 1937. A New Ordovician Fauna from Washington Land, North Greenland. Medd. om Gr^nland, 119, No. 1. 1937a. Ordovician and Silurian Faunas from Arctic Canada. Rept. Fifth Thule Exped., 1921-24, Gyldendalske Boghandel, Nord. Forlag, Copenhagen, 1, No. 5. Troedsson, G. T. 1926. On the Middle and Upper Ordovician Faunas of Northern Greenland. Part I. Cephalopods. Medd. om Grjzfnland, 71. 1928. Ibid., Part II, 72. 1936. The Ordovician-Silurian Boundary in Europe, Mainly in the Scandinavian- Baltic Region. Rept. 16th Internat. Geol. Cong., Washington, D.C. Twenhofel, W. H. 1914. The Anticosti Island Faunas. Bull. Geol. Surv. Canada, 3. 1928. Geology of Anticosti Island. Mem. Geol. Surv. Canada, 154. Tyrrell, J. B. 1892. Three Deep Wells in Manitoba. Trans. Roy. Soc. Canada, 9. Ulrich, E. 0. 1879. Descriptions of New Genera and Species of Fossils from the Lower Silurian about Cincinnati. Jour. Cincinnati Soc. Nat. Hist., 2. 1883. American Paleozoic Bryozoa. Jour. Cincinnati Soc. Nat. Hist., 6. 1889. Contributions to the Micro-paleontology of the Cambro-Silurian Rocks of Canada. Part II. Geol. and Nat. Hist. Surv. Canada. 1890. Paleozoic Bryozoa. Geol. Surv. Illinois, 8. 1890-91. New and Little Known American Paleozoic Ostracoda. Jour. Cincinnati Soc. Nat. Hist., 13. 1892. New Lower Silurian Ostracoda. No. I. Amer. Geol., 10, No. 5. 1894. The Lower Silurian Lamellibranchiata of Minnesota. Part 2. Paleontology. Geol. and Nat. Hist. Surv. Minnesota, 3. 1895. On the Lower Silurian Bryozoa of Minnesota. Part 1, ibid. 1897. The Lower Silurian Ostracoda of Minnesota. Part 2, ibid. BIBLIOGRAPHY 205 1911. Revision of the Paleozoic Systems. Bull. Geol. Soc. Amer., 22. 1926. Relative Values of Criteria Used in Drawing the Ordovician-Silurian Boundary. Ibid., 37. and Bassler, R. S. 1923. Paleozoic Ostracoda: Their Morphology, Classification and Occurrence. Maryland Geol. Surv. (Silurian Vol.), pp. 271-391. 1923a. Systematic Paleontology of Silurian Deposits. Ostracoda. Ibid., pp. 500-704. and Scofield, W. H. 1897. The Lower Silurian Gastropoda of Minnesota. Part 2. Paleontology. Geol. and Nat. Hist. Surv. Minnesota, 3. Warburg, E. 1925. The Trilobites of the Leptaena Limestone in Dalarne. Bull. Geol. Inst., Upsala, 17. Watson, T. L. 1897. Evidences of Recent Elevation of the Southern Coast of Baffin Land. Jour. Geol., 5. Weller, S. 1903. Report on Paleontology. The Paleozoic Faunas. Geol. Surv. New Jersey, 3. Wheeler, E. P. 1935. The Nain-Okak Section of Labrador. Geog. Rev., 25, No. 2. Whiteaves, J. F. 1890. Description of Eight New Species of Fossils from the Cambro-Silurian Rocks of Manitoba. Trans. Roy. Soc. Canada, 7, sec. 4. 1895. Systematic List, with References, of the Fossils of the Hudson River or Cincin- nati Formation at Stony Mountain, Manitoba. Geol. Surv. Canada, Paleont. Fossils, 3, pt. 2. 1897. The Fossils of the Galena-Trenton and Black River Formations of Lake Winni- peg and Its Vicinity. Ibid., pt. 3. 1899. Recent Discovery of Rocks of the Age of the Trenton Formation of Akpatok Island, Ungava Bay, Ungava. Amer. Jour. Sci., 7, ser. 4. Whitfield, R. P. 1878. Preliminary Descriptions of New Species of Fossils from the Lower Geological Formations. Ann. Rept. for the Year 1877, Geol. Surv. Wisconsin. 1882. Species from the Shales of the Hudson River Group. Geol. Wisconsin, 4, pt. 3. 1882a. Species More Particularly Characterizing the Galena Limestone. Ibid. 1895. Republication of Descriptions of Fossils from the Hall Collection in the American Museum of Natural History, from the Report of Progress for 1861 of the Geological Survey of Wisconsin, by James Hall, with Illustrations from the Original Type Speci- mens not Heretofore Figured. Mem. Amer. Mus. Nat. Hist., 1, pt. 2. 1900. Observations on and Descriptions of Arctic Fossils. Bull. Amer. Mus. Nat. Hist., 13. Wilson, A. E. 1926. An Upper Ordovician Fauna from the Rocky Mountains, British Columbia. Bull. Geol. Surv. Canada, 44. 1931. Notes on Baffinland Fossils. Trans. Roy. Soc. Canada, 25, ser. 3, sec. 4. 1938. Gastropods from Akpatok Island, Hudson Strait. Ibid., 32, ser. 3, sec. 4. Winchell, N. H. and Schuchert, C. 1893. The Lower Silurian Brachiopoda of Minnesota. Part I. Paleontology. Geol. and Nat. Hist. Surv. Minnesota, 3. 1895. Sponges, Graptolites and Corals from the Lower Silurian in Minnesota. Ibid. INDEX New names in italic type. Achatella 165 Actinoceras 134, 135, 138 sp. 134, 180 Actinoceratidae 134 Aillik Bay 16 Akpatok Island 106 Alcyonaria 70 Amalgamata 81 Amherst College, Hall Collection presented to 182 Ampyx(?) 183 Anorthosite 20 Anthozoa 68 Aparchites 171 whiteavesi 171 (?)sp. 171, 181 Apsidoceras elegans 196 Apsidoceratidae 133 Archaeocyathinae 59 Aretes 34 Arthropoda 152 Asaphidae 156 Asaphinae 156 Asaphus 183 canadensis 184 Assizes Bay 16 Atactoporella 81 cf. schucherti 81, 177 Atrypidae 102 Austinella 84, 88, 89, 91 cooperi 88, 90, 178, 185, 195 kankakensis 90, 91, 178 scovillei 89, 178 (l)subcircularis 90, 91, 178 Bairdiidae 176 Basilicus canadensis 184 Bassler, R. S. 84, 169, 170, 171, 172, 173, 174, 176, 182, 183, 187, 188, 190, 191, 195 Bathyurus sculpinensis 22 (?)sp. 22 Batostoma sp. 81, 177 Batostomellidae 83 Battle Harbor 16 Becher Peninsula 28, 38 Beecherella 174 Beecherellidae 174 Bellerophon similis 185 sp. 184 Beloitoceras arcticum 186 baffinense 186 plebium 194 (?)cornulum 186 Beyrichia symmetrica 183 Beyrichiacea 171 Billings, E. 59, 60, 61, 74, 157 Billingsites 192, 193 costulatum 196 Bishop's Island 40 Boulder reef 23 Boulders 50, 52 Brachiopoda 84 Brewster Point 45 Bryozoa 81 Bumastus 159 aplatus 159 sp. ind. 159, 180 Buthotrephis 183 Bythocypris 176 granti 186 reniformis 176 aff. cylindrica 176, 181 Bythopora 84 Calapoecia 74, 187 borealis 79 canadensis 74, 185, 192, 193, 195 anticostiensis 74, 177, 195 f. arctica 74, 195 ungava 74, 195 Calliops 163 Callocystidae 80 Callocystinae 80 Calymene 159, 160 croneisi 160, 161, 180 macmillani 161, 180 platycephala 160 senaria 160, 180, 183 Calymenidae 159 Calyptaulax 165, 166, 167, 168 compressa 166 glabella 166 goodridgii 167 holstonensis 168 sillimani 167, 181 Camarella owatonnensis 105 Camarellidae 94 Cameroceras proteiforme 125, 185 Cape Calhoun 106 Cape Chidley 26 Cape Mugford 24, 26 Carabocrininae 81 Carabocrinus 81 esthonus 81 sp. 81, 177 Carpender, J. N. 185 Cat Head limestone 190 Cephalopoda 125 Ceraurinus icarus 163, 196 noduliferus 163, 181 206 INDKX 207 Ceraurus 162 pleurexanthemus 186 tuberosus 162 cf. horridus 162, 180 sp. 162, 181 Charactoceras 133, 192 baeri 196 plicatus 134, 179 rotundum 134, 179 schucherti 133, 179, 186 Chasmops 165 Cheirocrinus 80 sp. 80, 177 Cheiruridae 162 Cheirurinae 162 Chonetes cf. striatella 183 Cirques 34 Clarke, J. M. 104 Clathrospira 114 conica 114, 185 Climacograptus bicornis 183 Clinoceras exiguum 186 Clitambonites 187, 190 Coastal range 33 Coelenterata 68 Columnaria (Favistella) alveolata 70, 177 rugosa 192 stokesi 193, 195 Conchidium nysius tenuicostatum 184 Constellariidae 82 Conularia asperata 193, 196 trentonensis 183 Cooper, G. A. 89, 166 Countess of Warwick Sound 30, 46 Cox, I. 74 Crepipora sp. undet. 185 Crevasses 33, 38 Crinoidea 80 Cromer, G. 44, 184 Croneis, Carey 161 Crowell, J. T. 123 Crustacea 152 Ctenodonta 106 baffinensis 106, 179, 185 carpenderi 185 cuneiformis 108 frobisherensis 185 subnasuta 108 ulrichi 107, 179 (?)subnasuta 185 cf. subnasuta 107, 179 Ctenodontidae 106 Cyathocrinidae 81 Cyathophyllidae 69 Cyathophyllum pickthorni 184 Cyclendoceras 192 Cyclonema bilix 183 Cyclora parvula 183 Cyclospira 84, 103, 105 bisulcata 104, 105, 178, 184 schucherti 103, 105, 178 vokesi 105, 178 sp. 184 Cyclospiridae 103 Cyphaspis(?) frobisheri 183 Cypridacea 174 Cyrtoceras baffinensis 186 cornulum 186 laticurvatum 143 manitobense 140, 186 Cyrtochoanites 134 Cyrtodonta gibbera 185 sillimanensis 185 Cyrtogomphoceras 146, 151 baffinense 147, 180 furnishi 148, 180 sp. I 149, 180 sp. II 149, 180 cf. baffinense 149 Cystoidea 80 Dalmanella 84, 91 corpulenta 93, 178 diminutiva 91, 178 ignota 93, 178 rogata 93, 178 sillimani 92, 178, 185 testudinaria 92, 93 cf. testudinaria 92, 178 (?)sp. 93, 178 Dalmanellacea 91 Dalmanellidae 91 Dalmanites (Pterygometopus) goodridgi 186 Davis Strait 24, 28 Delo, D. M. 163, 166, 168 Dianulites 82 petropolitanus 82, 177 sp. 82, 177 Diestoceras 151, 152 magister 152, 180 milleri 152, 180 schucherti 186 Dinorthidae 88 Dinorthis 91 iphigenia 193 proavita 193, 195 subquadrata 192, 193, 195 Diphyphyllum 186 Diplograptus dentatus 183 Dog Head limestone 190 Domed lakes 52 Dowling, D. B. 189, 190, 194 Drepanella symmetrica 183 Drift fossils of Ordovician age 21, 46 "Drift" snow 52 Echinodermata 80 Emerson, B. K. 182, 183, 184 Encrinuridae 159 Encrinurus 159 rarus 159, 180 sp. ind. 159, 180 Endoceras 125 baffinense 125, 179, 185 fulgur 126, 179, 196 manitobense 130, 179 2nj> ORDOVICIAN FOSSILS OF BAFFIN LAND Endoceras paliforme 130, 179 proteiforme 182, 183 proteiforme(?) 182 sp. I 125, 179 sp. II 126, 179 sp. Ill 127, 179 sp. IV 130, 179 Endoceratidae 125 Eomonorachus 165, 168 ddoi 168, 181 Eotomaria 113, 114 canalifera 114, 179 {t)robinsoni 113, 179, 185 Ephippiorthoceras 130, 131, 132, 192 baffinense 131 compressum 131 sp. I 131, 179 sp. II 132, 179 Eridotrypa 83 basskri 83, 177 mutabilis minor 84 simulatrix 83, 177 cf. aedalis minor 83, 177 Eskimos 18, 38, 39, 44, 50; ruins of houses of 45 Etheridge, R. 65, 66 Eucrustacea 169 Euomphalidae 114 Eurychilina 173 bassleri 173, 181 frobisheri 174, 183 manitobensis 173, 181 reticulata 173 sp. 174, 181 Eurychilinae 173 Eurystomites plicatus 133, 186 Euthyneura 123 Everett Range 32, 34 Favistella 69 sp. 69, 177 Favosites 186 Favositidae 74 Field, Stanley 67 Fistulata 81 Fletcher Island 45 Fluvio-glacial deposits 33, 45 Foerste, A. F. 85, 88, 131, 133, 135, 138, 140, 143, 146, 151, 160, 190, 191, 195, 197 Ford Harbor 20 Forteau Bay 15 Frobisher, Martin 28-30, 46-48 Frobisher Bay, 24-26, 28, 34, 45, 50, 184; fossil collections from 182 Furnish, W. M. 149 Fusispira 188, 190 inflata 185 nobilis 185 Gannet Island 16 Gastropoda 109 Glacial lakes 34; markings 16; striae 16, 23, 45 Glyptorthinae 88 Glyptorthis 84, 88 bellarugosa 84, 88, 178 Gomphoceras indianense 151 Goodridge, F. G. 185 Granite 44 Gregg, Clifford C. 143 Griffin Bay 34 Grinnell Ice-cap 32-38 Gumbel, C. W. 59 Halisitidae 77 Hall, Charles F. 30, 40, 42, 44, 182 Hall, James 104 Halliella 172 jaynesi 172, 181 labiosa 173, 181 retifera 172 sculptilis 173 Halysdtes 77, 186, 187, 193, 195 agglomeratiformis 77, 79, 177, 195 catenularia 184 quebecensis 192 catenulata(?) 182 gracilis 185 gracilis 79, 80, 192, 193, 195 robustus 80 cf. gracilis 79, 177 Harpedidae 154 Harpes 152, 154 sp. ind. 154, 180 Hebertella 88, 91 borealis85 Heleohtes 182 perelegans 79 Helicotoma planulata 184 rawsoni 22 (?)larvata 185 Hehotidae 70 Hesperorthinae 87 Hesperorthis 84, 87 interplicata 87, 178 Hinde, G. J. 59, 65, 66 Holochoanites 125 Holopea 122 arctica 185 (?)sp. 122, 179 Homotelus gratiosus 1% Hopedale 18 Hormotoma 111 gracilis cf. augustata 113 labradorensis 22 minuta 22 rotundivolvis 111, 179 salterill3 trentonensis 111 (?)major 111, 179 sp. I 112, 113, 179 sp. II 112, 113, 179 sp. Ill 112, 113, 179 Hudson Strait 24, 26, 28, 34 Huronia occidentalis 193, 196 INDEX 209 Hyolithes 123 crowelli 123, 179 Hyolithidae 123 Hypoparia 152, 154 Icebergs 16, 38 Ice-cap 38; continental 26; see Grinnell Ice-cap Ice mounds 52 Ice-sheet, continental 46 Ice-tongues 34, 38 Illaenidae 156 Illaenus 156 americanus 156, 157, 180 angusticollis 157, 180 baffinlandicus 156, 180 consimilis 156, 157, 180 crassicauda americanus 186 groenlandicus 156, 157, 180 punctatus 157, 180 cf. groenlandicus 158 sp. ind. 158, 180 Incertae sedis 59 Indian Harbor 16 Indunata 81 Ischadites 59, 61, 188 iowensis 61, 185 koenigii 66 murchisoni 67 Ischyrotoma 154 twenhofeli 154 (l)raymondi 154, 180 Isle of Ponds 16 Isochilina 170 convexa 170, 181 Ottawa 170 vaurealensis 170, 181 Isotelus 156 gigas 156, 180, 186 latior 156, 180 cf. iowensis 156, 180 Jackman's Sound 26, 32, 38 Jaynes, John 173 Jordan River 28, 40, 42, 44 Kay, G. M. 192, 193 Kiglapait Range 26 Kindle, E. M. 187 Kionoceras scalariforme 186 Kochoceras 137, 138 cuneiforme 137, 138, 180 magnicameratum 138 sublentiforme 138, 180 troedssoni 138, 180 sp. 140, 180 Kodlunarn Island 30, 46, 48 Kokenia costalis 185 Koojessee Inlet 38, 39 Krausella 174 inaequalis 174, 175 rawsoni 174, 181 Krausella cf. anticostiensis 183 cf. inaequalis 175, 181 sp. 175, 181, 186 Labradorite 20 Lambe, L. M. 70, 76 Lander sandstone 192, 194 Leda 106 Leperditacea 169 Leperditellidae 171 Leperditia 169, 170, 183, 188 altal83 cabotensis 170 canadensis 183 crittanica 169 ulrichi 169, 170 cf. ulrichi 169, 181 Leperditiidae 169 Leptaena rhomboidalis 98 unicosta 192, 193, 196 Leptobolus lepis 183 Leurorthoceras 135 hanseni 135 (?)baffinense 135, 180 (?)cf. baffinense 137 Lichenocrinus affinis 185 Lindstrom, G. 114 Lingula curta 183 Liospira americana 185 Lophospira 109, 110, 122 spironema 185 cf. augustina minnesotensis 109, 179 sp. I 110, 179 sp. II 111, 179 Lower Mottled limestone 190; =Dog Head limestone 190 Lowville limestone 188 Lunoid markings 16, 18 Lupton Channel 48, 50 Lyellia 186, 187, 195 affinis 185, 195 Maclurea 187, 188, 190 crassa 185 magna 182 Maclurina 44, 109, 114, 115, 119, 188, 189, 194, 195 cuneata 115, 185 manitobensis 115, 185, 195 cuneata(?) 117, 179 manitobensis(?) 115, 179 Maclurites 44, 109, 114, 115, 119, 189, 195 acutus 196 crassus 115, 119 crassus(?) 119, 179 (?)sp. 121, 179 MacMillan, Donald B. 162 Macrocypris cf. subcylindrica 183 Meta Incognita 28, 42, 44, 45 Miller, A. K. 152, 192, 194 Minturn Bay 34 Modiolodon arctica 185 Mollusca 106 210 ORDOVICIAN FOSSILS OF BAFFIN LAND Monorachos 165 schucherti 166 wimani 166 Monticulipora parasitica plana 195 Monticuliporidae 81 Murchison, R. I. 66 Murchisonia (Lophospira) tricarinata 184 Nain 20 Napotlulagatsuk Island 21 Naskapi Indians 24 Nautiloidea 125 Nematopora 187, 190 ovalis 81, 188 Neumatoceras 143, 144, 146 gibberosum 144 (?)tumidum 146, 180 New York Lyceum of Natural History, Charles F. Hall collection presented to 182 Newell Sound 38 Nidulites gregarius 193, 195 Nileus vigilans 186 Northern Lights 39 Northwest Passage to China 28, 30 Nucula 106 Nuculacea 106 Nunatak 38 Onchometopus susae 193, 196 Oncoceras arcticum 186 magnum 146 plebium 184 tumidum 146 Oncoceratidae 140 Opisthobranchia 123 Opisthoparia 154 Ordovician fossils 46 Orthacea 85 Orthidae 87 Orthis (Hebertella) bellarugosa 185 (Hebertella) borealis 85, 185 (Plectorthis) jamesi 184 (Dinorthis) meedsi 185 (Plectorthis) plicatella 88, 185 (Dalmanella) testudinaria 184, 185 tricenaria 87, 178, 185 cf. davidsoni 184 Orthoceras 182 bilineatum 186 formosum 130 olorus baffinensis 186 porteri 186 scalariformis 186 laqueatum(?) 183 Orthoceratidae 130 Orthochoanites 130 Orthoidea 85 Orthotetinae 98 Ostracoda 169 Outwash plain 33 Pachydictya pumila 81, 188 Paleofavosites prolificus 193, 195 Parastrophinella 84, 94 hemiplicata 94, 178, 185 minor 94, 178, 185 Paul Island 20 Peary Arctic Expedition, Seventh 185 Pelecypoda 106 Pelmatozoa 80 Pentameracea 94 Pentamerid 184 Pentameroidea 94 Phacopidae 163 Phacops 183 brongniarti 167 Phragmoceratidae 146 Plasmopora 70, 186, 187, 195 lambei 70, 72, 177, 185, 195 pattersoni 72, 177, 185, 195 Plasmoporinae 70 Platystrophia 84, 86 acutilirata 187 biforata 86, 185 crassa 193, 195 elegantula triplicata 86, 178 magnisulcata 86, 178, 185 Platystrophiinae 86 Plectambonites serecea(?) 97 sericeus 187 sp. undet. 183 Plectorthidae 85 Plectorthinae 85 Plectorthis 84, 85, 91 fissicosta 90, 91 inaequiconvexa 85, 178, 185 plicatella 85, 178 trentonensis 85, 178 Pleistocene epoch, elevation since 33, 46 Pleurotomariidae 109 Pomiadluk Point 18 Porocrinus shawi 185 Port Manvers 26 Porter, R. W. 42, 44 Poterioceras sp. undet. 186 Prasopora sp. 81, 177 Preservation Island 40 President's Seat 34 Primitia 171, 186 cincinnatiensis 172, 181, 196 frobisheri 183 mundula 171 muta 183 Primitiidae 171 Primitiinae 171 Prionodesmacea 106 Proparia 159 Prosser limestone 188, 192 Protowarthia pervolutus 185 Protremata 85 Pteropoda 123 Pterygometopinae 163 INDEX 211 Pterygometopus 163, 164, 165, 166, 168 callicephalus 163, 164, 165, 166 brevis 165, 181 confluens 166 eboraceus 166 goodridgii 166 holstonensis 166 intermedius 168 lincolnensis 166 schmidti 165 sclerops 163 sp. ind. I 166, 181 sp. ind. II 166, 181 Ptilodictya flagellum 195 Putnam Highland 106 "Quor" water 54 Rafinesquina 84, 94 declivis 95, 96, 178 subnutans 95, 178 deltoidea 97 lata 196 mucronata 95 productiformis 96, 178 pronis 94, 96, 178 squamula 95 sp. 96, 178 Raflnesquininae 94 Raised beaches 15, 23, 46; wave-cut 32 Rauff, H. 59, 61 Rawson, Frederick H. 175 Raymond, P. E. 154, 155, 159 Receptaculites 59, 60, 61, 65, 67, 68, 188, 194; morphology of 59-61; termi- nology of 61, 62 arcticus 63, 65, 66, 177, 185 jonesi 66 occidentalis 63, 65, 66, 67 oweni 63, 65, 66, 185, 195 pearyi 79 (!)fieldi 66, 177 sp. 63, 67, 177, 182 Receptaculitidae 59 Red River, fauna 189; formation 189-194, 196 Remopleuridae 155 Remopleurides 155 striatulus 155 sp. 155, 180 Resolution Island 24, 26, 28 Rhipidoglossa 109 Rhombifera 80 Rhombotrypa subquadrata 195 Rhynchonella 183 bisulcata 105 increbescens 184 Rhynchonellacea 100 Rhynchonellidae 100 Rhynchotrema 84, 100 anticostiense 101, 178, 193, 196 breve 100, 178 capax 100, 178, 192, 196 Rhynchotrema capax arcticum 100, 178 inaequivalvis 185 increbescens 102, 178 laticostatum 102, 178 sp. 101, 178, 193 Rhynchotreminae 100 Richmond age, species of 195 Robinson, Ralph 114 Roche moutonnees 18 Rock basin lakes 18 Rock beacons 45 Saffordia modesta 185 Salter, I. W. 182 Scenidium sp. undet. 183 Schuchert, C. 65, 70, 81, 104, 105, 146, 182, 184, 185, 186, 188, 194, 195, 197 Scofield, W. H. 115, 119 Sculpin Island 21 Seelya(?) ulrichi 185 Selkirk limestone 190 Serrated peaks 34 Shaw, A. V. 185 Silliman, Benjamin, Jr. 42 Silliman's Fossil Mount 28, 40^4, 46, 186, 187; age of 189; chemical composition of 43; collections from 182, 184, 185; columnar structure of 43; Lowville limestone at 188; ostracods from 184; physical properties of 43; synopsis of fauna of 177 Skenidiidae 86 Skenidioides(?) 84, 86 anthonense 87 (?)merope 87 (?)sp. 86, 178 Solenopleuridae 154 Sowerbyella 84, 97 sp. 97, 178 Spiriferacea 102 Spotted Island 16 Spyroceras baffinense 186 olorus 194 porteri 186 Stevens, R. P. 182 Stewartville limestone 188, 192, 193, 195 Stictopora ramosa(?) 183 Stony Mountain formation 190 Streptelasma 68 breve 68, 177 corniculum 69, 177, 185 robustum 195 amplum 68, 177 rusticum 195 (?)sp. 184 sp. I 68, 177 sp. II 68, 177 sp. Ill 68, 69, 177 Stropheodonta leda 193 Strophomena 84, 98, 99 fluctuosa 98, 99, 196 . plandorsata 196 planumbona 184 21 -J ORDOVICIAN FOSSILS OF BAFFIN LAND Strophomena trilobata 98, 178 undulosa 98, 178 sp. I 99, 178 sp. II 99, 178 Streptoneura 109 Striations 18 Strophomenacea 94 Strophomenidae 94 Sylvia Grinnell River 28, 38, 39 Syringopora conspirata 195 Tabulata 74 Tarns 34 Teichert, C. 70 Tellinomya alta 184 Telotremata 100 Tentaculites 183 Tetrabranchiata 125 Tetracoralla 68 Tetranota obsoleta 185 Thuleoceras ornatum 186 Tidal flats 40 Tides 28, 40, 50 Topography, coastal 38 Torngat 26 Trepostomata 81 Triarthus becki 183, 187 Trilobita 152 Trochoceras(?) baeri 133 sp. undet. 184 Trocholites sp. undet. 184 Trochonema 121 beachi 121 rectangulare 122 (Eunema) robbinsi 185 umbilicatum 185 cf. umbilicatum 121, 179 (?)sp. 122, 179 Trochonematidae 121 Trochus dali 114 wisbyensis 114 (?)sp. undet. 185 Troedsson, G. T. 77, 92, 157 Turritoma cf. ada 22 Twenhofel, W. H. 190 Tyrrell, J. B. 190 Ulrich, E. O. 84, 108, 115, 119, 187, 195, 197 Upper Mottled limestone 190; = Selkirk lime- stone 190 Vanuxemia abrupta 185 baffmensis 185 Vokes, H. E. 106 Waddell Bay 45 Ward's Inlet 28, 45 Watt's Bay 34, 38 Westenoceras 44, 140 deckeri 141, 180 greggi 109, 141, 180, 189, 195 (?)tumidum 146 White, A. H. 185 Whiteaves, J. F. 190, 191 Whiteavesia symmetricus 185 Whitella arcticus 185 Whitfield, R. P. 184, 185 Wilsonoceras mccharlesi 196 Winchell, N. H. 65, 104 Winnipeg limestone 191 Winnipeg sandstone 190 Winnipegoceras 143 laticurvatum 143, 144, 180 Yoldia 106 Zaphrentidae 68 Zaphrentis(?) sp. 184 Zygospira 84, 102 maynei 102, 178 modesta 103 recurvirostris 103, 178 Zygospirinae 102 TY\£ v\tt^ x uf \Wt N0M V- ob\ ,