5E3 A REVIEW OF THE NON-MARINE FOSSIL MOLLUSCA NORTH BY 0. A.[WHl£E, M. D. Matthew Library 403 LETTER OF TKAXSMITTAL. SIR: In accordance with your request that I should prepare an arti- cle for your annual report upon a subject which has for some years been engaging my attention, I have the honor to submit herewith the follow- ing, which I have entitled UA Keview of the Non-Marine Fossil Mol- lusca of North America." In the preparation of this article I have endeavored as fully as prac- ticable to follow your suggestion, that it should be as free from techni- cal forms and methods as the nature of the subject will allow. I have therefore endeavored to address the general reader rather than the spe- cial investigator,* but I have given copious references in the form of foot-notes, so that those who wish to pursue the subject further may readily refer to nearly all that has Been published upon it in America. Your recognition of the fact that there is a natural and growing desire on the part of intelligent readers to know something of the geo- logical history of the predecessors of the animals with which they are more or less familiar, or which are frequently referred to in the books they read, would be expected by those who are familiar with the graphic style of your own writings; and your wish to gratify that desire is too obviously correct to make any explanation or apology proper on the part of a specialist who may be called upon to communicate with the public in the form proposed by you. In the selection of a subject, I have chosen one which, although primarily based upon molluscan species which are all extinct, embraces the consideration of, or reference to, living forms, congeners of those which have ceased to exist, that are scattered over all parts of the country. It is, therefore, a subject which a far greater number of per- sons will find of ready application within their every day experience than many others which the wide range of paleontology might furnish*. In illustrating this subject on the accompanying plates, I have in each case selected such figures (which are in part copies of illustrations already published by various authors, but largely newly drawn from the type-specimens of the various species) as would exhibit the form, and such features of the objects, respectively, as strike the eye of the ordinary observer, omitting, in many cases at least, those details of structure which more especially engage the attention of the special investigator. 405 406 LETTER OF TEANSMITTAL. While the material upon which the present statements and discus- sions are based is in many respects very incomplete, it is nevertheless extremely suggestive and instructive, and a knowledge of it is sure to awaken a strong interest in future labors in the same field that has been fruitful of these results. A majority of the illustrations accompanying this article have been drawn directly from specimens in the United States National Museum, permission having been kindly given to do so by Professor Spencer F. Baird, the Director of the museum. A large part of the specimens thus used are the original types of the species which are illustrated. . The drawings have been made with pen and ink by Dr. J. C. McCon- nell, of Washington, and they have been reproduced by the photo- engraving process. Yery respectfully, 0. A. WHITE. Hon. JOHN W. POWELL, Director of the United States Geological Survey. CONTENTS. Page. Letter of transmittal 405 Introductory remarks 411 Annotated and illustrated catalogue 420 Conchifera 420 OstreidtB 420 Anomiidaa 421 Mytilidae 423 Unionidse 424 Cyrenidae 435 PisidiidsB 440 Corbulidae 441 Gasteropoda ~. 443 Auriculidae 443 Limnaeidse 444 Physidse 449 Ancylidae 451 Vitrinidae .'. 452 Arionidse ? 452 HelicidsB 453 Pupidse 455 Succinidae 457 Neritidae 457 Cerithidse , 459 Melaniidao 459 Ceriphasiidas 462 Rissoidae 465 Viviparidae 466 Valvatidse 470 Tabular view of the non-marine fossil mollusca of North America 472 Spurious and doubtful species 478 General discussion 479 407 ILLUSTRATIONS. Page. Plate 1. Devonian 488 2. Carboniferous 490 3. Jurassic and Triassic ? 492 4. Cretaceous 494 5. Cretaceous 498 6. Bear River, Laramie 498 7. Bear River, Laramie 500 8. Bear River, Laramie 502 9. Laramie ' ; f 504 10. Laramie .' 506 11. Laramie 508 12. Laramie 510 13. Laramie ......._r 512 14. Laramie 514 15. Laramie 516 16. Laramie 518 17. Laramie 520 18. Laramie 522 19. Laramie 524 20. Laramie 526 21. Laramie 528 22. Laramie 530 23. Laramie 532 24. Laramie 534 25. Laramie 536 26. Laramie 538 27. Laramie 540 28. Eocene 542 29. Eocene 544 30. Eocene 546 31. Eocene 548 32. Miocene and Pliocene?.. 550 A REVIEW OF THE NON-MARINE FOSSIL MOLLUSCA OF NORTH AMERICA. BY C. A. WHITE, M. D. INTRODUCTORY REMARKS. In this article I propose to review the principal known facts concern- ing the fossil fresh- water, brackish-water, and land mollusca of North America, taking up each family in the order of systematic classification, and tracing the history of its occurrence, so far as it has been learned, from the earliest known appearance of any of its 'species Avithin the present limits of North America until the present time; and to follow the same with some general discussion of certain questions that are sug- gested by the facts thus set forth. For the purpose of giving an ap- proximately chronological view of the different faunse the figures are arranged on the plates under headings that indicate the successive geo- logical periods to which they belong. The plan proposed involves at least brief mention of every species of non-marine fossil mollusca yet dis- covered in North America, and the illustration of nearly all of them by fig- ures, which show their external form and leading features, so far as they are known. To avoid frequent repetition, it is mentioned here that all statements made in this article in regard to the range of families and genera in time, must be understood as applying to North America alone, unless it is otherwise expressly stated. The scope of this article, as indicated by the title and foregoing "re- marks, is a very wide one; and the presentation of such a title would seem to imply the known existence of much material upon which to base a discussion of the subject. Lest I should seem to assume greater knowl- edge of this subject than the facts will warrant, it may be stated that while the material upon which our present knowledge of it is based is really considerable and very important, it is nevertheless true that as regards a continuous history of the fauna3 herein discussed, and the geological epoch in which our most common living molluscan types really originated, our knowledge is very imperfect. Enough material, however, has been collected to throw much light upon the character of the ancestral representatives of many of the families which are herein mentioned. It is proposed to go so far only in the discussion of these 411 412 NOX-MARIXE FOSSIL MOLLUSCA. fossil forms as we are warranted in doing by the well-ascertained char- acter of the evidence adduced. As to the scope of the general subject, although it embraces the three categories of non-marine mollusca, namely, those of brackish-water, fresh -water, and land habitat, it is still small as compared with that of the great mass of that portion of the molluscan subkingdom which is embraced by the marine mollusca. Not only is the diversity within the three categories of molluscan forms which are herein discussed almost incomparably less than that which obtains among marine mollusca, but a greater proportion of the remains of formerly existing non-marine than of marine mollusca, have almost certainly been destroyed as the result of geological changes and other causes which will be suggested, or they have failed to be preserved in an available condition for study. Therefore the record furnished by the fossil non-marine mollusca is much more imperfect than it is in the case of the marine mollusca. Still, the scope of this subject is a very broad one, even with our present incom- plete knowledge of its details, and the discussion of many interesting points pertaining to it must be deferred to other occasions. Again, while the three non-marine categories of mollusca, especially the first two, in the order in which they have been named, may be de- fined from each other with a good degree of accuracy in the case of their jiving representatives, yet it has not always been found easy to say whether some of those fossil forms whose nearest living congeners are found exclusively in perfectly fresh-water may not have lived in waters which contained at least a small proportion of salt ; but this subject will be further referred to on subsequent pages. Neither are we positive in all cases that those species which we refer to a land habitat were really land pulmonate mollusks, or that they may not have been in some cases palustral pulmonates, or, possibly, gill-bearing mollusks. But generally these determinations are made with much confidence, based upon the kuown correlation of shell characteristics with the soft parts of the liv- ing mollusks which formed them. The more indefinite boundary of the scope of the present article is that which I have drawn between the brackish-water and marine forms. The difficulty of drawing such a line arises largely from the fact that some of the genera which have more or less abundant representatives in brackish waters have also representatives in marine waters 5 but I have regarded those strata as of brackish- water origin, which have been found to contain by natural deposition forms whose living congeners are found in brackish waters, even though such fossil forms are found associated with those on the one hand whose living. congeners are some- times, but not not always, found in marine waters ; or, on the other hand, with those whose living representatives are known only in fresh waters. Such a commingling of forms as is here indicated really occurs in nu- merous instances, especially in the strata of the Laramie group. Thus theassociatioumoneandtbesiimcsti^ WHITE.] INTRODUCTORY REMARKS. 413 &c., is held to indicate a brackish- water origin for such a stratum, even though it holds, associated with those shells, such forms as Unio, Vivi- pqrm, Goniobasis, &c., especially if such strata alternate (as is often the case in the Laramie Group) with strata which contain on the one hand only such fresh-water forms as Unio, ViciparuSj &c., and on the other hand such saline-water forms as Ostrea, Anomia, &c. This view is also confirmed by the fact that in the Laramie Group Corbicula, Corbula, and Neritina are frequently found so associated with Ostrea and Anomia as to plainly indicate that they all lived together. It is thus clearly shown that a part of the forms discussed in this article have near allies in strata of marine origin, and also many near allies now living in truly marine waters, and none in fresh waters j but the commingling of these fossil species of undoubted saline habitat with others which clearly indicate that they lived in water of far less than marine saltness, makes it neces- sary to regard the former as members of a brackish- water fauna, and, therefore, as coming within the scope of this article. In some cases the brackish waters that, by the presence in the depos- its they have left of such fossils as have been referred to, are indicated as having then prevailed, were plainly those of estuaries, which indented the coasts of formerly existing seas at the mouths of then existing rivers. But the greater part of the species enumerated in this article, which are regarded as having had a brackish-water habitat, come from strata (namely, those of the Laramie Group) which bear evidence of having been deposited in a great inland sea, in parts of which sea brackish waters alternated with fresh, or nearly fresh- waters. The facts upon which this conclusion is based have been presented in other publications, and are repeated to some extent upon following pages in this article. Before proceeding with the enumeration of the specific forms of non-marine mollusca which have been discovered in ^North American strata, and the geological position which each fauna represented by them respectively occupies, it is necessary to present a brief tabular statement of the arrangement or order of the geological formations, beginning not with the earliest known fossiliferous rocks in the geologi- cal series, but with the formation which has furnished the earliest known molluscan forms that come within the scope of this article, namley, Devo- nian. This tabular view of the formations has been made with especial ref- erence to those which have been recognized in Western North America, because it is there that the greater part of the fossils have been collected which are discussed in the following pages. It may not be eiftirely unnecessary to state that, although the terms group and formation are somewhat variously used by different writers, the strata that were formed in a period or epoch of geological time are usually and properly referred to by the same name as that of the period or epoch in which they were formed. Thus, the following table of geo- logical time is really a table of the formations that were produced dur ing that time. 414 NON-MARINE FOSSIL MOLLUSCA. Subdivisions of geological time. Time. Ages. Periods. Epochs. Post- tertiary ...... < Recent. Cenozoic orM^ronmlian j Qnarternary. Pliocene. 1 j Mcsozoic Laramie. Cretaceous. Eocene. I ! Carboniferoaa Devonian 1 .. f Jurassic. Triassic. Permian. Coal-Measures. Lower Carboniferous. No special explanation of the terms or names used in this table, with perhaps the exception of Laramie, is deemed necessary, because they are to be found in ail text-books of geology now in use; but some supple- mentary explanation of the terms that, in connection with those which have become so commonly known, have been used by the various geolo- gists who have made original investigations in Western North America is necessary to enable the general reader to understand clearly the use of them that is made in the following pages. The term Laramie Group, although it is unknown except in the geology of Western North America, will be mentioned oftener perhaps in this article than the name of any other formation ; because a greater number of the species herein mentioned come from that group of strata than from any other. This name is applied to a large and very important formation which, in the western part of the continent, conies between the well- recognized marine Cretaceous strata below, and the equally well-recog- nized Tertiary strata above. Geologists are not agreed as to whether this great group should be referred to the Tertiary or Cretaceous period, some contending for the former and some for the latter reference. The truth appears to lie between the two opinions, and I have elsewhere presented reasons for regarding this group as occupying a transitional position between the Cretaceous and Tertiary.* Neither the Lar- amie Group nor any true geological equivalent of it is at present known anywhere except in Western North America. It there occupies or is found at various localities within a large region, the present known limits of which may be roughly stated as extending from Northern New Mex- ico on the south to the British possessions on the north, and from the vicinity of Great Salt Lake on the west to a present known distance out upon the Great Plains of more than 200 miles from the eastern base of tlie Rocky Mountains. It has been traced within tlie western boundary of both Kansas and Nebraska. In the course of the earlier geological investigations which were made in the west, the strata of this great group, which represents a distinct 'An. Rep. U. S. Geol. Snr. Ter. for 1877, pp. 259-265. Ib. for 1878, pai t I, pp. 51, 52. WHITE.] INTRODUCTORY REMARKS. 415 period in the geological history of North America, were studied independ- ently by different investigators, at various more or less widely -separated localities within the region that has just been indicated, which resulted in the strata of that group receiving different names in different regions. Thus, Meek & Hay den gave the name "Judith Elver Group" to those strata in the valley of the Upper Missouri, near the mouth of Judith Eiver, which were found tocontain brackish-water fossils. They gave the name "Fort Union Group" to strata of similar faunal character near Fort Union, also in the valley of the Upper Missouri, but at a con- siderable distance to the eastward of the Judith Eiver region. They also gave the name "Lignitic Group" to those strata in Colorado east of the Eocky Mountains which were found to contain a similar fauna. Professor Powell, studying the strata in Wyoming and Utah, gave the name" Point of Eocks Group" to .a series which agrees mainly with that which is now called Laramie, and which had been referred to by Meek & Hayden as the "Bitter Creek Coal series." The strata which are herein called the Bear Eiver Laramie beds of Southwestern Wyoming and the adjacent parts of Utah were by Meek and Hayden generally re- ferred to as the "Bear Eiver Estuary beds." Mr. King was the first to place all these local groups together (except those of the Upper Missouri Eiver region) under the general and comprehensive name of Laramie Group. I subsequently showed that the Judith Eiver, Fort Union, Lig- nitic, and Point of Eocks groups are all connected together by specfiic identity of fossils in their respective strata.* I have therefore treated the strata of all those different regions respectively as only local devel- opment of parts of one great group 5 but I have retained the local names which they originally received from different authors, only substituting the word "beds" in most of those cases for that of "group," using the latter term in the more comprehensive sense. Thus, I speak of the Judith Eiver beds, Fort Union beds, Bear Eiver beds, &c., while referring them all to the great Laramie Group. A similar duplication of names, arising from similar circumstances, also exists in reference to the earlier or earlist members of the purely fresh-water Eocene series, which immediately succeeds the Laramie Group. Thus, the names " Wahsatch Group" of Hayden, "Vermilion Creek Group" of King, and "Bitter Creek Group" of Powell are re- garded as substantially equivalent, or as representing one and the same division of the Eocene epoch. To aid the reader, who may be assumed to be unfamiliar with the details of western geology and with the names which the different series of strata in the West that are necessarily often referred to in this article have received from different investigators, the following summary of facts and opinion is given: 1. The "Judith Eiver Group," " Fort Union Group," " Lignitic Group," *Au. Rep. U. S. Geol. Snr. Terr, for 1877, pp. 252-265. 41 G NON-MARINE FOSSIL MOLLUSCA. "Bitter Creek Coal series," "Point of Rocks Group/7 and "Bear River Estuary beds "* are all parts of the great Laramie Group. 2. The Laramie Group is regarded as a transitional group between the Cretaceous and Tertiary series, and therefore as representing a period partaking of both the Mesozoic and Cenozoic ages. 3. The " Wahsatch Group," " Vermilion Creek Group," and " Bitter Creek Group" are regarded as at least approximately equivalent strata, constituting the oldest member of the purely fresh- water Eocene Tertiary series of deposits in the West. 4. The Green River and Bridger Groups are respectively the second and third members of that fresh- water Eocene series. 5. The Wind River Group of Wyoming is regarded as of Eocene age. 6. The White River Group of Dakota is regarded as of Miocene age. 7. The fresh-water deposit of the Kawsoh Mountains, in Northern Nevada, and its equivalent in Southern Idaho, called by King the Truckee Group, are regarded as of Miocene age. 8. No strata of Pliocene age are referred to in this article except those of Cache Valley, in Northern Utah, because with that exception no non-marine inollusca are known to have been obtained from any North American strata which may be referred to that epoch ; unless certain forms of Pliysa be also excepted, which have been found in the Brown's Park Group of Powell, in Southern Wyoming. Our knowledge of the various geological formations which are found within the limits of North America enables us to trace with a good de- gree of satisfaction the history of the evolution of the continent or the progressive steps by which it was elevated above the level of the sea. A brief outline, or at least a statement of some of the phases of this history, as it is understood by geologists, is necessary to a proper un- derstanding of the facts which are presented in the following pages. Without going into the details of investigations by which geologists have arrived at their conclusions, it may be stated that the continent in its present shape has been produced by the coalescence of two or more principal portions which were elevated above the level of the sea in the earlier geographical ages in consequence of the progressive elevation of the continental area. The two principal portions of the continent pre- vious to the Cretaceous period were an eastern and western one respect- ively, and before the close of that period they were separated by a broad stretch of open sea. By the continued slow rise of the whole continental area this broad stretch of open sea became land-locked at the close of the * It should be remarked hero that the molluscan species of the Bear River beds and their equivalents are all different from those of the Laramie Group elsewhere; but those strata are referred to the Laramie Group because they hold the same strati- graphical relation to the Cretaceous below and the Tertiary above that the typical Laramie strata do in other regions, and also because they contain a brackish- water fauna. Whether this difference in the faunae is due to difference in age, contemporane- ous isolation of waters as separate seas during the Laramie period, or to some other cause, is not yet known. WHITE.] INTRODUCTORY REMARKS. 417 Cretaceous period and beginning of the Laramie, changing the area thus inclosed to a brackish-water sea, in which the strata that we now call the Laramie Group were deposited. By the continued elevation of the continental area that sea became much reduced in size and entirely fresh at the close of the Laramie period. * During the immediately succeeding Eocene Tertiary epoch at least, the great fresh-water lakes that were thus formed prevailed_over a large part of that area which in the Laramie period had been occupied by brackish, and previously by marine, waters. Then began the series of movements in the earth's crust which resulted in the elevation of the plateaus and the great systems of mountains of Western North America, into the structure of which these Laramie and Eocene strata enter. Some portions of the western part of the continent continued to be occu- pied by fresh.water lakes of the kind last referred to, during the middle and latter portions of the Tertiary period ; but they were much less in size than those which previously existed. They also gradually became smaller, and finally disappeared by being drained of their waters ; or remnants of them remained to become the salt- water lakes of to-day. The incompleteness of that portion of the geological record which is furnished by the fossil remain's of the three categories of mollusks, which form the subject of this article, has already been referred to, and the causes of it are very apparent when it is remembered how small a pro- portion the non-marine have always borne to the marine mollusca; and also how small a proportion of fresh and brackish water deposits there must always have been in comparison with marine deposits. The extensive fresh and brackish water deposits of Western North America are remarkable exceptions to the general rule, that extensive geological formations are of marine, or open sea, origin; and we have therefore in that region, and for the epochs which those formations rep- resent, an unusually full record of non-marine and terrestrial life; for it must be remembered that those formations contain many remains of terrestrial vertebrates, and an abundant flora, as well as of fresh-water and land mollusca. This statement of facts naturally leads to a brief consideration of the conditions which prevailed in former geological pe- riods, and which conduced to the preservation of the molluscan forms herein discussed, when so large a proportion of their kinds in other parts of the world were destroyed. While the remains of aqueous mollusca were readily entombed and preserved in the sedimentary deposits of the waters in which they lived (which deposits afterward became rocky strata), those of land mollusca must have been transported from the land into such waters, where alone they could have been preserved, and where in fact they did receive the same entombment with those that had lived there. This transportation of the shells of land mollusca was doubtless in most cases effected by the currents of rivers near the banks of which the mollusks lived, and into the waters of which they were swept in time of flood. And yet an 27 G 418 NON-MARINE FOSSIL MOLLUSCA. unexpectedly large proportion of the known fossil pulmonate mollusca are those whose habitat was constantly upon the land. The conditions, however, which prevailed during the Coalmeasure period of the Car- boniferous age, and under which the immense quantities of vegetable material that we now know as coal were preserved, were necessarily some- what favorable to the preservation of such land mollusca as may have found a habitat among that vegetation. The paucity of the remains of such mollusca that have yet been discovered in the extensive coal-bear, ing strata of that early period seems to prove that they could not then have been very abundant 5 but the discoveries of Dawson, Bradley, and Whitfield show conclusively that a well-developed and widely differ- entiated land moluscan fauna existed at least as early as the middle of the Carboniferous age, and probably much earlier. From the Coalmeasure period until that of the Laramie the few re- mains of non-marine mollusca that have been found in North American strata present indications that the layers in which they were discovered were deposited under estuary, palustral, or limited lacustrine conditions, reference to which will be made in connection with the separate men- tion of the species on following pages. The conditions which prevailed in Western North America during the Laramie and Eocene periods have already been indicated, and for fuller details the reader is referred to the works before cited. Although there are really many facts now known which throw light upon the physical conditions that prevailed, and the molluscan fauna3 which lived in Western North America during the various geological periods from the later Paleozoic to the present time, a part of which have been referred to, the following counter-facts should also be men- tioned, because they show how far from perfect or continuous the geo- logical record really is, in relation especially to the non -marine mollusca. Eivers, ponds, and marshes have necessarily existed ever since any considerable portion of the continent rose above the sea, and those rivers and ponds, without doubt, all had their own molluscau fauna3 ever since the later portion of Paleozoic time, if not from a still earlier date, and yet no trace of any river deposits, except those of estuaries (and few of these are known), has yet been discovered which pertain to any geological epoch except that of the Post-Tertiary. The same can hardly be said of palustral deposits, because much, if not all, of the coal must have been produced under palustral conditions j and yet it is a note- worthy fact that the greater part of the known fossil palustral mollusca ha ve^ been found preserved in lacustrine deposits together with mol- lusks of lacustrine origin, and very few in true palustral deposits. Although it is only in the eastern half of the continent that any re- mains of non-marine mollusca have been found in strata of Paleozoic age, the remains of such mollusca as have been found there in strata of any of the periods between that of the Coalmeasures and the Post-Ter- tiary are few and unimportant.* * See remarks on a following page on spurious and doubtful species. WHITE.] INTRODUCTORY REMARKS. 419 The same might also be said of that portion of the continent which borders upon the Pacific Ocean, and for the same periods, but for the very few Unione forms which the Cretaceous deposits have furnished there, and which have special interest in connection with other fossil Unionidse mentioned in this article. Therefore, almost the whole of our present knowledge of the character of the non-marine molluscan types which existed during the whole of Mesozoic and Tertiary time and of the order of their succession has been derived from discoveries of their remains which have been made in the interior region of the western half of the continent, mainly in connection with the surveys that have been prosecuted under the auspices of the government. Moreover, the dis- coveries that have been made in North America up to the present time give us very little information of any molluscan fauna, except the marine, for the Miocene epoch, and still less for the Pliocene. Therefore this review of the non-marine molluscan faunae of the continent, although it is intended as a synopsis of all the species that are at present known, is something like a chapter, or parts of chapters, taken at random from a book ; but these selections are of such a character as to give us a very good'indication of what the whole book, figuratively speaking, must be. This indication is all the more clear because of the fact that while every species that is discussed in this article, from whatever formation it comes, is regarded as extinct, the great majority of the genera, and even the sections or subdivisions of the genera, are precisely the same as those which we find represented by living forms. In the case of many of the fossil forms, so clearly are these familiar generic and subordi- nate types expressed, that the fossil species are often found to resemble those now living so closely as to require careful scrutiny to discover wherein they differ. This persistence through long periods of geologi- cal time, of even the simpler types of non-marine mollusks, after they were once established, is a remarkable and interesting fact. Individ- uals, generations, and species died, as the epochs succeeded each other, but the types* have remained to this day. *The word "type," as used by different authors, lias often necessarily a somewhat indefinite meaning ; but as used in this article it may be defined as an ideal repre- sentation of the essential characteristics of a group of species, usually applied to a group which may embrace a genus, or only a subordinate division of a genus. In the latter case, I use the designation subordinate type. I do not use the term type in any case as interchangeable with any of the names that are used in systematic classifica- tion, such as species, genus, family, &c. ; but sometimes it may be equivalent in scope with any of them ; as, for example, when only a single species of a subgenus, genus, or family is known. Thus, although types may have no material existence in one sense, they are found to have been more persistent in time or duration than specific forms; for we find that many of the types, as above defined, which now exist among living mollusca also existed in various geological epochs as far back as Mesozoic, or even earlier, time ; but every known fossil species in which those types have been expressed have suc- cessively become extinct. ANNOTATED AND IULTJSTRATED CATALOGUE. OONCHIFEBA. The families of the Conchifera, which are represented by the fossil species discussed in this article, are those only which are represented among the living non-marine mollusca; because, so far as we now know, there is not a single representative of an extinct family among all those species. Moreover, the principal genera are the same among both the fossil and recent forms, and in only a few cases at most is there a sub- generic difference, or even a difference in the subordinate types into which certain of the genera may be divided; although all the species are regarded as extinct. It should be understood that this article is a review, and* not a re- vision, of published species. Therefore, the genuineness of the different species which have -been published by various authors is seldom called in question, even when it is "doubted, as it is in a number of instances. It is thought best on this occasion to present the subject somewhat his- torically, and defer a critical revision of the species to another time. OSTREID.E. Although the Ostreidse of the present time are much less frequently found living in the waters of the open sea than in those of bays and estuaries, the fossil shells of all the various generic groups of that family are often found quite abundantly associated with those of such molluscan forms as must be regarded as having been denizens of the open sea. Indeed, both the Mesozoie genera Gryphcea and Exogyra seem to have been invariably of open-sea habitat; while Ostrea proper has, in all the Mesozoie and Cenozoic epochs, existed in both marine a'nd brackish waters; but the last-named genus seems to have always been in past times the only representative of the OstreidaB that has lived in brackish waters, while none of the family have probably ever lived in perfectly fresh waters. The most noteworthy examples of the fossil brackish-water Ostreida3 of North America, namely, those of the Laramie Group, occur in strata that contain no truly marine forms, but which are frequently found to closely alternate with other strata in which fresh-water and land mol- lusca prevail; and, indeed, there are often found associated with these shells of Ostrea those of species whose liviug representatives exist only in fresh waters. But as it is my intention to prepare a separate essay for a future report on all the fossil OstreidaB of North America, little more than incidental reference will be made to this family in this arti- cle— even to those species of Ostrea which constitute parts of the brack- ish-water fauna herein discussed. Since, however, the molluscan fauna 420 WHITE. 1 ANNOTATED CATALOGUE. 421 of the great inland brackish-water sea which existed during the Lara- mie period will be necessarily somewhat frequently referred to and briefly discussed on following pages, it is thought best to make the series of its illustrations the more complete by presenting a few figures of the more characteristic forms of its Ostreidae, which will be found on Plates 9, 10, 11, and 12. Five species of Ostrea* have been described and published -by various authors from strata which are now regarded as belonging to the Laramie Group; but in view of the known wide range of variation among the species of this genus, and the actual discovery of many intermediate forms which connect at least a part of those supposed species together, it is now thought that the strictly specific forms of Ostrea which have been discovered in the Laramie Group do not number more than two or three at most, t It is interesting to note how closely some of these ancient species of Ostrea are "allied to living forms, a good example of which is afforded by 0. wyomingensis, as may be seen by comparing the figures of it on Plates 10, 11, and 12, with the shells of the common Ostrea virginica, now liv- ing so abundantly uppn our Atlantic coast. So closely, indeed, are some of the fossil specimens like living ones that, but for their partially min- eralized condition, the former might easily be taken for damaged ex- amples of the living species. While the Ostreida3 have formed a more or less prominent feature of all the molluscan faunse whose remains are found in all the marine de- posits from the Jurassic period to the present time, we have yet discov- ered no remains of the family in any North American strata of any of the epochs between the close of the Laramie period and the beginning of the Post Tertiary which can be properly referred to a brackish water origin. Therefore the consideration of this family as contributing any of its species to non-marine molluscan faunse must cease in this article with the references that are made to the fauna of the Laramie Group. Precisely similar remarks maybe made concerning the genera Anomia, Corbicula, Corbula, and Neritina so far as regards the extinction of all the species of those genera in the waters of the Laramie Sea as a conse- quence of their becoming completely freshened at the close of that period; and, also, because of the non-discovery of any brackish water deposits of a later date than that period in which such remains may have been deposited. ANOMIID^E. Since among fossil fauna3 Anomia is an almost constant associate and sometimes, as, for example, in many of the, layers of the Laramie Group, * These were named, respectively, Ostrea subtrigonalis Evans & Shumard ; 0. gldbra Meek & Hay den ; 0. arcuatilis Meek; 0. insecuris White ; and 0. wyomingensis Meek. Examples of all these forms are figured on the plates accompanying this article. t See remarks on this subject in An. Rep. U. S. Geol. Sur. Terr, for 1877, p. 162. Also, ib. for 1878, Part I, p. 56. 422 NON-MARINE FOSSIL MOLLUSCA. apparently the only immediate associate of Ostrea, the same general remarks may be made concerning the Anomiidse that have just been made concerning the Ostreidss so far as they are applicable to the sub- ject of this article. The earliest known North American species of Ano- mia have been found in Cretaceous strata, the greater part of them having by the different authors who have described tbem been reported as as- sociated with forms that must be regarded as of marine origin, but some of them are known to have existed in the estuaries that indented the sea coasts of the Cretaceous period. One estuary species, A. propatoris, White, was discovered by Mr. Meek in an interesting estuary deposit of Cretaceous age at Coalville, Northern Utah, where it was found associated with Cyrena, Unio, Val- vata, Melampus? Physa, and also with some marine forms. It is rep- resented on Plate 5. In the marine Cretaceous strata of the same neighborhood some imperfect examples of Anomia have been found which seem to be specifically identical with Anomia propatoris. If this identification is correct it seems to prove that the species in question ranged from marine to brackish waters. This supposition is a plausible one, because certain living species of mollusks are known to have a similar range of habitat. Anomia propatoris is very closely like some of the various forms of A. micronema presently to be mentioned, and the former not improbably represents the latter species ancestrally.* Two other species of Anomia only are known, which come within the scope of this article, both of which are found in the strata of the Laramie Group in Colorado and Wyoming 5 although it is by no means unlikely that other species existed in the brackish waters of all the epochs that have passed since the family was first established.. These two species are A. micronema and A. gryphorhynchus, Meek. They are both represented on Plate 12. Both are from the Laramie Group, and although in the same neighborhood they are seldom found associ- ated in one and the same layer. It has been the subject of frequent remark that not a single example of the under valve of either of the three species of Anomia herein no- ticed has ever been discovered, although hundreds of examples of the upper valves of at least two of the species has been obtained, at many different localities, in a good state of preservation. I was lately so fortunate however as to find in the Laramie strata of Northeastern Colorado several examples of the under valve of A. micronema, one of which is illustrated by Fig. 11, on Plate 12. That the under, or byssus- bearing, valves of A. micronema at least have been so generally de- stroyed is due to the fact, first, of their extreme thinness, and, secondly, to the fact that, with the exception of a thin, porcelanous layer in the middle portion, the whole valve is composed of a prismatic layer, like *See remarks in An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, p. 14, pi. 12, fig. 15. WHITE.] ANNOTATED CATALOGUE. 423 the shell of Pinna; the pearly layer, which gives such strength to the upper valve, being apparently entirely wanting in the lower. This prismatic layer breaks up into its component prisms with great facility. The characteristics of the under valve of A. micronema, as well as those of the upper valve, show it to be a true Anomia; thus presenting evi- dence of the great antiquity of the genus just as it exists to-day. MYTILIDJi. This family is very sparingly represented in the brackish water strata of North America, and not at all, so far as is now known, in either any existing fresh waters, or in any strata of purely fresh- water origin; yet the family has representatives in some of the strata of all the geological ages, from the Paleozoic to the present time. The only genus of this family which has been recognized among the fossil collections from our brackish water strata is Volsella Scopoli; and all the examples of it that have been discovered in those strata are apparently referable to the subgenus Brachydontes Swainson. Two species have been described from the Laramie Group of Wyo- ming and Colorado, namely Volsella (Brachydontes) regularis and V. (B.) laticostata White ;* both of which are represented on Plate 13. An un described form of this genus is also known to exist in the Bear Eiver Laramie beds of Southwestern Wyoming. At least one species, which is closely allied with those just mentioned as coming from the brackish-water strata, is known to exist in the marine Cretaceous strata of the same region in which those Laramie species occur, and it is not improbable that they are genetically related with each other. The genus Dreissena Van Beneden, a living species of which is so common in certain of the rivers of Europe and Western Asia, and which genus is so abundantly and variously represented in the fresh- water Tertiary deposits of Eastern Europe, is not known to be represented in North America by a single spec'es, either living or fossil. Neither is Adacna Eichwald known in North America, either fossil or recent, although so common in Eastern Europe and Western Asia, in brack- ish waters and brackish- water formations. The genus Mytilus, although it is recognized by Meek in the marine Cretaceous strata of the epoch which immediately preceded the Lara- mie period, seems not to have survived in the brackish waters of that period as did Ostrea, Anomia, and Volsella. In the foregoing discussion of the three families Ostreidae, Anomiidse, and Mytilidae, representatives of which are now so abundant upon our marine coasts, it will be seen that especial reference has been had to the faunaB of the Laramie and other great groups of strata in the west- ern portion of the continent. This arises from the fact which has already been stated or alluded to, that in the epochs represented by those groups, the conditions were, in that region, widely extended and * An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, pp. 58, 59, pi. 25, figs. 3 & 4. 2 424 NON-MARINE FOSSIL MOLLUSCA. very favorable for the developement of brackish and fresh- water faunjg; while whatever of estuary deposits may have been made during the periods that have elapsed since paleozoic time in those regions which now constitute other portions of the continent, have been nearly or quite destroyed by the geological changes that have occurred , or they have hitherto escaped discovery. Consequently, as has already been remarked in relation to the Ostreidse, discussion of not only the brack- ish-water representatives of these -three families, but of all brackish- water forms will cease in this article with the references that are made to the fauna of the Laramie period. Discussion of the fresh-water and laud mollusca will be continued to a much later epoch by .references ta their fossil remains, because favorable and extensive fresh water con- ditions continued in Western North America long after the wide-spread brackish waters of the Laramie period had ceased there. But even as regards these purely fresh- water and land molluscan families, few of their remains have yet been discovered which are refer- able* to the epochs which passed between the Eocene and the present time. These deficiencies of the geological record and their zoological bearing will be made apparent as the different known faun»3 are pre- sented in their order on the following pages. UNIONHXE. For various reasons, no family of non-marine fossil mollusca is of greater interest than the Unionidae, especially since the discovery of the large number of species in the Mesozoic and Oenozoic strata of Western North America, and of the rich Unioue fauna of the Tertiary deposits of Eastern Europe. Although certain shells found in the Carboniferous and Devonian strata of Europe and America have been referred to the Unionidae by different authors, the accuracy of such reference has been by others seriously questioned 5 and American paleontologists at least have of late years not generally recognized as belonging to that famliy any shells found in strata of earlier than Mesozoic time.* Prof. James Hall has, however, recently expressed the opinion t that the two bivalve species, which were named by Vanuxem Cypricardites cattskillensis and 0. angus- tata, respectively,! belong to the genus Anodonta; and that the Mont- rose and Oneonta sandstones (later Devonian) in which those species occur, were "deposited under estuary and fresh-water conditions." Aside from the apparent Unione characteristics of these shells, and the other facts upon which Professor Hall bases the opinion he has ex- pressed, the wide differentiation, which is now known to have become fully established among the Unionidae, at least as early as the later portion of Mesozoic age, points to a very early period for the origin of the family. * See remarks on a following page on spurious and doubtful species. t See " Science " for December, 1880. jVanuxem's Rep. Geol.-, 3d District, New York, p. 186. WHITE.] ANNOTATED CATALOGUE. 425 It is not improbable, therefore, that representatives of the Unionidae ex- isted as early as the later Devonian, as has been suggested by Professor Hall. This opinion, furthermore, is all the more probably correct, be- cause of the known fact that a well developed land-molluscan fauna existed during the Coalmeasure period, and apparently also in the De- vonian, all the known species of which are mentioned on the following pages and figured on accompanying plates. Although it may not be regarded as certain that the Cypricardites cattsTcillensis and C. anyustata of Vanuxem really belong to the genus Anodonta, copies of Yanuxem's original figures are given on Plate 1, for the purpose of comparison. Dr. J. W. Dawson, in his Arcadian Geology, second edition, describes seven species of edentulous bivalves from the Coalmeasure strata of Nova Scotia, under the generic name of Naiadites. He states his belief that they are the shells of brackish- water or fresh -water mollusks " allied to the Mytilidae or Unionidae." The shell structure, as given by Dr. Daw- son, is like that of the Unionidae and unlike that of the Mytilidae. It seems, therefore, not improbable that at least a part of his species really belong to the Unionidae. Three of those species, namely, Naiadites car- bonaria, N~. elongata, and N. Icevis, are represented on Plate 2, the fig- ures being copies of Dr. Dawson's original illustrations in the work referred to. If these Devonian and Carboniferous shells do not really belong to the Unionidae, the earliest known members of that family now known to exist in North American strata are two or three species, specimens of which were collected by Prof. E. D. Cope in the valley of Gallinas Creek, New Mexico, from strata which he regarded as of Triassic age.* These shells belong unquestionably to the genus Unio proper, as is shown by the character of the hinge and the muscular markings. The outer pris- matic layer of the shell which characterizes the Unionidae is also well pre- served on some of the specimens. One of these forms, which is figured on Plate 3, was described by Mr. Meek,t under the name of U. cris- tonensis, and specific names were also proposed for the two other forms, the specimens of which he deemed to be too imperfect for characterization . J There are some reasons for regarding the strata from which these shells were obtained as of Jurassic instead of Triassic age, but further inves- tigation is needed before such an opinion can be confidently expressed. The figure of U. cristonensis is drawn from one of the best of Mr. Meek's type specimens, but which is nevertheless very imperfect. The species has never before been figured. While U. cristonensis is probably the most ancient published North American species of Unio, this portion of the subject ought not to be * An. Rep. Expl. and Sur. west of the 100th meridian, for 1875, p. 81. t An. Rep. Expl. and Sur. west of the 100th meridian, for 1875, p. 83. t These two names are respectively Unio gallinensis and U. lerrce-rubrce ; but the spec- imens to which they are applied are really too imperfect to justify the application of any specific names. 426 NON-MARINE FOSSIL MOLLUSCA. passed over here without reference to the fact that Dr. S. G-. Morton, Mr. T. A. Conrad, and Dr. Isaac Lea have all described fossil species which they regarded as belonging to the Unionidse. They were, however, either incorrectly referred to that family, or the formations from which they were respectively obtained are incorrectly stated ; and they are, therefore, enumerated under the head of spurious and doubtful species on following pages. That the Unionidas existed within the area that now constitutes West- ern North America in the Jurassic period, and that the genus Unio of Ketzius had then not only become established, but had reached a good degree of differentiation as regards the establishment of subordinate groups of forms within that great genus, is apparently beyond reason- able doubt 5 and in this article the question is treated as affirmatively settled. At the s'ame time it should be stated that in the case of at least a majority of the alleged discoveries of fresh- water inolluscan species in Jurassic strata, some doubt has been thrown upon the gen- uineness of the fresh- water origin of the strata in which they were de- posited, or upon the actual Jurassic age of those strata. The first discovery in North American Jurassic strata of shells which are referable to the Unionidse was announced by Meek & Hayden in connection with the publication of Unio nucalis,* which is figured on Plate 3. Those authors, however, expressed a remote doubt as to whether the strata in question, which occur in the vicinity of the Black Hills, are really of Jurassic age. No other examples of this .species be- sides the type specimens have ever been discovered. They are shown to be those of true Unio by the hinge characters observable upon one of the specimens ; and the outer prismatic shell-layer is observable on all of them. They were found associated with shells, which Meek & Hayden referred to the genera -Planorbis, Valvata, Viviparus, Neritella, and Lioplacodes respectively. Another Jurassic species referable to this family is Unio stewardi, White, which was described from some imperfect specimens that were collected from Jurassic strata by Mr. J. F. Steward in Northern Utah.t Fig. 1, on Plate 3, is an outline illustration of this species which has been made up by help of several fragments, no perfect example having ever been discovered. It is believed to represent closely the outline and general aspect which the species presented while living. It is an interesting form, because it illustrates the fact that at least one of the subordinate types of Unio that now exists among the living species of the Mississippi Eiver system was established at that early epoch. The next known member of the Unionidae, the appearance of which is to be mentioned in the order of geological time, is an interesting form * Paleontology of the Upper Missouri, p. 92, pi. iii, fig. 13. t Powell's Report, Geology of the Uinta Mountains, p. 110. WHITE.] ANNOTATED CATALOGUE. 427 which was described by Meek & Hayden,* from Southeastern Dakota, under the name Margaritana nebrascensis. It was obtained from the Da- kota Group, which is the earliest group of the Cretaceous strata in the North American series ; and it was found associated with Cyrena dakotensis and Pharella f dakotensis of the same authors. These forms indicate a brackish- water, probably estuary, origin for at least the layers in which those fossils occur, although the remains of marine mollusca are found in other parts of the same group. Margaritana nebrascensis is repre- sented by two figures on Plate 4, which figures are drawn from the prin- cipal type specimen. In shape and general aspect this shell resembles some of the living forms of Margaritana, but it is of a somewhat different type from any known living species of that genus. It differs still more from any of the other known fossil Unionidse, except the form whicli was described by Gabb t from the Cretaceous strata of Vancouver's Island under the name of U. hubbardi. This suggestion of congeneric relationship is based upon the external characteristics alone which both present, because nothing is yet known of the character of the hinge of U. hubbardi. The hinge of M. nebrascensis, as ascertained by Meek, seems to warrant its reference to the genus Margaritana, and if this reference is correct, that species is, with the probable exception of the U. hubbardi of Gabb, the only known North American fossil form which can be properly referred to Margaritana. But, as before intimated, it probably belongs to a sub- ordinate type of that genus which early became extinct. Unio hubbardi is represented by copies of Mr. Gabb's figures on Plate 5. Mr. Gabb also described and figured | another species, a strange bi- alate form from the Cretaceous strata of California, under the name of Unio penultimus,, of which he seems to have had very imperfect speci- mens. Figure 1, on Plate 5, is a copy of Mr. Gabb's original figure of this form. He expressed no doubt of the correctness of his refer- ence of that species to the genus Unio, and> notwithstanding its unusual form, there appears to be no reason to suppose that it may not belong at least to the Unionida3. If it really is a member of this family it presents an interesting example of a subordinate type which has become extinct, while many co-ordinate types which existed contemporaneously with, or shortly after it, have come down to the present time unchanged. It is a significant and interesting fact, especially in connection with the refer- ence of his Coalmeasure genus Naiadites to the Unionidae by Dawson, that both of the Uniones which were described by Gabb from the Creta- ceous strata of the Pacific coast were found in strata associated with the coal beds of that period. The three last-mentioned species of thellnionidse are, with one excep- tion, all that are at present known to have existed within the area which *U. S. Geol. Sur. Terr., vol. ix, p. 114, pi. i, fig. 5. t Paleontology of California, vol. ii, p. 190, pi. 30, fig. 86. t Paleontology of California, vol. i, p. 182, plate 24, fig. 164. 428 NON-MARINE FOSSIL MOLLUSC A. is now occupied by the North American continent during the epochs that all geologists agree in referring to the Cretaceous period. It can- not be doubted, however, that many representatives of the family really lived during" that period, the remains of most of which are probably for- ever lost, but some of which we may yet hope to discover. The excep- tion that has been referred to is a species, the only known remains of which consist of a few fragments, too imperfect for specific characteri- zation, which were found in the Estuary deposit at Coalville, Utah, which has already been referred to as furnishing Anomiapropatoris, and is yet to be mentioned in connection with certain other species. The cause of the apparent paucity of Unione and other non-marine molluscan remains in strata of Cretaceous age, is not, probably, that such inollusca did not then exist in very many places in greater or less abundance ; but it is probably due to the fact that few of the non-marine deposits of those epochs have escaped destruction. We come now to the consideration of a geological period, namely, the Laramie (which is also a remarkable period of time in the evolutional history of the Unionidse), in which the physical conditions within the area now occupied by the North American continent were exceedingly favorable to the existence 'and development of non-marine mollnsca. The chief of these conditions was the wide prevalence of brackish and fresh waters during the whole of that period. During the Laramie period there existed a Unione fauna that, for differentiation into a great varietv of subordinate types, is truly remarkable when we remember that it oc- curred at a time so remote. It is also a remarkable fact that a large proportion of these types are precisely those which now characterize the peculiar and rich Unione fauna of the Mississippi drainage system. A part only, and apparently an unimportant part, of those subordinate types that existed during the Laramie period appear to have become extinct. In tracing the evolutional history of any family of mollusca we should, in a general way at least, expect to find that the simplest forms were the first to appear in the order of time; and although simplicity of form of the shell is not by any means a necessary correlative of simplicity of structure in the mollusk which produced it, we nevertheless naturally inquire whether the simple shells of Anodonta did not precede in geolo- gical time the more complicated shells of Unio. This may or may not have been the case; for the difference in actual zoological rank between the two genera is at best measured only in part by the differences in the shells of each genus. If, however, Professor Hall's suggestion is correct, that the two De- vonian forms that have already been referred to, belong to the genus Anodonta; and if Dr. Dawson is correct in referring his Carboniferous genus Naiadites to the Uriioniilae, the evidence seems to be strongly in favor of the opinion that Unio was actually preceded in geological time by Anodonta and other edentulous Unionidse. WHITK.J ANNOTATED CATALOGUE, 429 On the other hand, if those two Devonian species are rejected as not being members of the UnionidaB, the earliest species of Anodonta that are yet known in North American strata have been obtained from the Laramie Group, although, as we have seen, diverse and characteristic forms of true Unio existed as early at least as the Jurassic period $ and Margaritana appears also to have existed in the earliest epoch of the known North American Cretaceous. One of the two species of Anodonta, which have been discovered m the Laramie Group, namely, A. propatoris White, from the Judith Eiver beds of the Upper Missouri Kiver region,* is represented on Plate 19. In form and general aspect it is exceedingly like certain species which are now living in North American waters. The example represented by Figs. 7 arid 8, on Plate 19, is not of fully adult size, as is shown by an accompanying figure of another, but less perfect example ; but it serves to illustrate the form of the species with considerable accuracy. Fragments found associated with them show the characteristic edentu- lous hinge of Anodonta, one of which is represented on tbat plate. In- deed there can be no reasonable doubt that both Unio and Anodonta have come down from at least the close of Mesozoic time, wholly un- changed, not in generic characters only, but in those characteristics also which separate subordinate types within those genera from each other. The other Laramie species of Anodonta, namely, A.parallela White,t was obtained from the valley of Crow Creek, Northern Colorado ; but only fragments of the shell have yet been discovered, Fig. 5, on Plate 19, being a restoration of the form, which has been prepared by aid of those fragments. It is an unusually elongate form, but it is appar- ently a true Anodonta. At the present time lacustrine waters appear to form a more COD ge- nial habitat for Anodonta than fluvatile waters do, although various species of that genus occur in both ; but notwithstanding this fact, no specimens of Anodonta have been discovered in any of the great lacus- triue deposits of Tertiary age which succeeded those of the Laramie Sea in Western North America, although several species of true Unio, as well as other fresh-water inolluscan forms, are frequently found in those deposits. Notwithstanding the fact that so few of the remains of Ano- donta have been discovered, it cannot be doubted that it was continu- ously represented by different species from at least as early a period as the Laramie down to the present time. { Ee turning again to the genus Unio, we find it remarkably well repre- sented in the strata of the Laramie Group and those of the immediately succeeding fresh-water Eocene Tertiary groups. That division of the Laramie Group which is known as the Bear Eiver *An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, p. 62, pi. 24, fig. 2. t An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, p. 62, pi. 24, fig. 3. jSee reference to Anodonta decurtata, Conrad, under the head of spurious and doubt- ful species. 430 NON-MARINE FOSSIL MOLLUSCA. beds, and which is better known in Southwestern Wyoming and the adjacent parts of Utah than elsewhere, is probably somewhat earlier in its origin than those divisions of the group which occur in other por- tions of that great western region.* Therefore the two species of Unio which those strata have furnished may be properly first considered. One of these species, which is represented on Plate 6, is interest- ing as the type of what was regarded by Mr. Meek, who described the species under the name of Unio belliplicatus,} as a distinct subordi- nate type of Unio, to which he subsequently gave the subgeneric name of Loxopleurus. J As this species has the true hinge structure, pallial and muscular markings, and ordinary external form of Unio, its assumed type characteristics consist only of its peculiar style of surface plication. It may well be questioned whether this feature is sufficient to base a subgeneric distinction upon, especially as the bent plications seem to consist essentially of a blending of small concentric folds, which are developed only near the beaks, with radiating folds, both of which are respectively found upon various other species of Unio. The other species which has been referred to as occurring in the Bear Kiver Laramie beds, and with which U. belliplicatus is usually associ- ated, is Unio vetustus Meek,§ which -is figured upon Plate 7. This species has an external form somewhat similar to that of U. bellipli- catus, but its surface is plain, except that a few more or less distinct concentric wrinkles are usually observable upon the beaks ; and some- times one or two faint radiating raised lines appear upon each side of the postero-dorsal portion. Both species have all the characteristics of true Unio well developed, and both have the front shorter than is usual among living species of that genus which have a like transversely oval outline. In the latter feature they agree with other fossil species, which are presently to be noticed. Those strata belonging to the great Laramie group, which are some- what extensively developed in the Upper Missiouri Kiver region, and which have become generally known as the Judith Kiver beds, have furnished a considerable number of species of Unio, besides one species of Anodonta, which has already been mentioned. All the species of Unio noticed in this article, especially those of the Laramie and fresh- water Eocene groups, may be divided into several natural sections, each section representing a subordinate type of Unio, which, with one doubtful exception presently to be noticed, has repre- * This suggestion that the Bear River beds are older than the other portions of the Lararaio Group is not made with entire confidence. It is based wholly upon the greater dissimilarity that appears between the fauna of the former than that of the latter when both are compared with living mollusca. This dissimilarity may, of course, be due toother causes than the supposed greater length of time since the existence of the Bear River fauna than has passed since that of the other portions of the Laramie group was living. tGeol. Sur. 40th Parallel, Vol. iv, p. 165, pi. xvi, fig. 4. t See U. S. Geol. Sur. Terr., Vol. ix, p. 515. $ Geol. Sur. 40th Parallel, Vol. iv, p. 164, pi. XVI, fig. 5. WHITE.] ANNOTATED CATALOGUE. 431 sentatives now living in the waters of the Mississippi drainage system. These types of living Uniones, which have such well-defined represent- atives among the fossil species of the Laramie Group, are among those which, being characteristic of the molluscan fauna of the Mississippi drainage system, have come to be generally known as " North Ameri- can types of Unio." So unmistakable is their relationship that no rea- sonable doubt can be entertained that the fossil, represent the living forms ancestrally. In only one particular, if we except the peculiar plication of U. belliplicatusj do any of the "fossil species of Unio of Laramie or Tertiary age assume a characteristic which is either not present or not clearly recognizable in any living species among North American Uniones. This excepted characteristic consists in the extreme shortening of the shell in front of the beaks in certain of the species which have also a considerable transverse elongation and an approximately oval outline ; that is, instead of having the beaks situated near, or only a little in advance of, the mid-length of the dorsal border, as they are in all the living oval and some of the shorter forms, the beaks in the case of the fossil forms in question are placed very near to the front. Short forms of Unio, of living as well as fossil species, have their beaks placed thus far forward, but attention is called to the fact that it is only in the fossil species that this peculiarity has been observed in connection with such shells as are much elongate'd transversely. A living species, which per- haps more nearly than any other approaches in this respect the fossil species referred to, is U. clavus Lamarck, which is a common shell in the Ohio Eiver and its tributaries. But this species is, in reality, only one of the short subtriangular forms, which is a little more than usually elongate. The Unio subspatulatus of Meek & Hay den,* from the Judith Biver beds, which is illustrated on Plate 14, may be taken as an example of an elongate shell with a shortened front, such as has been referred to. In this case, however, there is an unusual narrowing of the shell pos- teriorly. • Associated with U. subspatulatus, and closely related to it, is another form which was described by the same authors under the name of Unio dancej and which is represented on Plate 17. This species has also been somewhat doubtfully identified in the Laramie strata of Southern Wyoming, further mention of which fact is made on a following page Two other species have been obtained from the Judith Elver beds, namely, Unio deweyanus Meek & Hayden,| and U. cryptorhynchus White,§ both of which possess the shortened front in connection with a transversely oval outline, which features have already been discussed. * U. S. Geol. Sur. Terr. , vol . ix, p. 518, pi. 41, fig. 1. t U. S. Geol. Sur. Terr. , vol. ix , p. 517, pi. 41, fig. 3. tU. S. Geol. Sur. Terr., vol. ix, p. 519, pi. 41, fig. 2. $ An. Rep. U. S. Geol. Sur. Terr., for 1878, Part I, p. 68, pi. 24, fig. 1. I 432 NON-MARINE FOSSIL MOLLUSCA. These two species are represented on Plates 17 and 14 respectively. Some imperfect specimens of a form that seems to be specifically identical with U. cryptorhynchus have also been discovered in the Laramie strata at Black Buttes station. The correctness of this identification is ren- dered the more probable, because of similar identification of other mol- luscan species in both regions, one of which has already been mentioned. Of the Uniones that are yet known from the Judith Kiver beds, two species remain to be noticed namely, U. primcevus and U. senectus White,* which are represented on piates 14 and 19 respectively. These two species differ much in external form, but both are marked by small rugose plications upon the postero-dorsal portion of the sur- face, a feature which is not unusual among living North American species of Unio, but which is possessed by few of the known fossil species. The aspect of these shells is so suggestive of certain features pre- sented by some of the living forms of Unio just referred to, that it is only their fossilized condition which at first view conveys to the mind an impression of their great antiquity. One other species, Unio prisons Meek & Hayden,t has also been ob- tained fro m the Laramie strata of the Upper Missouri Eiver region ; but this one is from the Fort Union beds which occur in a part of that great region which lies far to the eastward of that in which the Judith Eiver beds are found. This species is of an 'ordinary oval outline, with a moderately short front, but without any noteworthy peculiarities. It is represented on Plate 14 by a copy of Mr. Meek's original figure. In a single stratum of the Laramie Group at Black Buttes station, in Southern Wyoming, nearly a dozen species of Unio have been found, among which are some of the most interesting fossil forms of that genus that have ever been discovered: Some of these species have the peculiarly shortened front, together with a transversely oval form, of which mention has already been made; but in their general character- istics others of them are peculiarly like certain forms that are now liv- ing in the waters of the Mississippi drainage system. Among these species from the Black Buttes locality is Unio couesii, White,! the largest species of that genus which has ever been found in North American strata. It is represented on Plate 16. Its large size, massive test, and general aspect strongly recall certain of the large Uniones that are found living in the waters of the Wabash and other rivers of the Mississippi drainage system. Associated with U. couesii is another species, which is nearly as large, but of different form, namely, U. endlichi White, § which is represented on Plate 15. * An. Rep. Sur. Terr, for 1878, Part I, pp. 69, 70, pi. 29, fig. 3, and pi. 28, fig. 1. tU. S. Geol. Sur. Terr., vol. ix, p. 516, pi. 43, fig. 8. {An. Rep. U. S. Geol. Sur. Terr., for 1878, Part I, p. 64, pi. 27, fig. 1. $ An. Rep. U. S. Geol. Sur. Terr., for 1878, Part I, p. 66, pi. 26, fig. 1. WHITE.] ANNOTATED CATALOGUE. 433 The shells of both these large species are strong and massive, and both have strong and well developed cardinal and lateral teeth, such as are observable upon the shells of the large living river Uniones. The other species of Unto that have been obtained from the Black Buttes locality have all been described by me under the following names respectively: Unio propheticus, U. brachyopisthus, U. proavitus, U. aldricMj (7. goniambonatus, U. holmesianus, and a form which I have doubtfully referred to the U. dance of Meek & Hayden * has also been obtained there. These seven species are represented by appropriate figures upon Plates 13, 15, 16, and 19. They cannot fail to be especially interesting to those who are familiar with the UnioDe fauna of the Mississippi drainage system. The form which is represented by figures 1 and 2, on Plate 18, has already been referred to as having been doubtfully identified with Unio dance, the type specimens of which species were obtained by Meek & Hayden from the Judith River beds of the Upper Missouri Eiver region. It is not improbable that further comparison will make it necessary to regard the Black Buttes form as a distinct species. In some respects, at least, the most interesting of these fossil species of Unio is U. holmesianus White. It is especially noteworthy as indi- cating, in connection with its associates, the wide diversity of subordi- nate types that the genus Unio had attained in the Laramie period, and also as affording a fine fossil example of one of the most characteristic subordinate types of Unio that are now peculiar to North American fiuvatile waters. Unio gonionotus White t is illustrated on Plate 13. It was discov- ered, by Professor Powell, in the Laramie strata of Southern Utah, where alone any specimens of the species have yet been found. It is an interesting form, especially because of the strong plications which it bears, and which are similar to those that characterize various living species, and 'also .because it possesses the excessively shortened front which has before been noticed as characterizing other fossil Uniones. Only one other species of Unio, which is referred to tne Laramie Group, remains to be noticed by name in this article j but, judging from various fragments that have been found at different localities, it is quite certain that several, perhaps many, other species exist there. In- deed, the known wide diversity of type that the genus Unio had attained during the Laramie period seems necessarily to imply that a greater num- ber of specific forms then existed than have yet been discovered. The species last referred to, and which is illustrated on Plate 18, 1 have described under the name of Unio mendax.% Specimens of it * For original descriptions and figures of these seven forms see An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, pp. 62-68, pi. -2-2, 26, 27, and 29. t An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, p. 71, pi. 26, fig. 2. tBull. U. S. Geol. Sur. Terr., vol. iii, p. 605. 28 G 434 NON-MARINE FOSSIL MOLLUSCA. have been collected, by Professor Powell, from certain strata in the Caiion of Desolation, £,nd others, by one of the parties under Lieuten- ant Wheeler, from the coal-bearing strata at Wales, Utah, all of which probably belong to the upper portion of the Laramie Group. The speci- mens obtained at Wales were erroneously referred by me to U. vetustus Meek,* which species U. tnendax resembles in certain particulars. In the Eocene fresh- water deposits, which immediately succeeded the Laramie, several species of Unio have been found 5 and it is a note- worthy fact that while there was great diversity of form and consider- able diversity of surface ornamentation among the species of Unio that existed in the Laramie period, all the species of that genus which have yet been found in the purely fresh- water Eocene deposits have a trans- versely oval form and plain surface; that is, there are among the latter no short forms, like several of those of the Laramie Group and many among living species, and none of them have the surface marked by plications, rugae, or pustules; nor are they marked in any other manner except by the ordinary concentric lines of growth. Most of these oval shells also have the beaks placed at least a moderate distance from the front, as is usual in the case of living species of oval form; but one of them at least possesses a shortened front, like that of several of the Uniones of the Laramie Group which have already been noticed. The species referred to is Unio clinopisthus White, which is described and figured for the first time, as follows: Unio clinopisthus (sp. nov.), Plate 28, Figs. 1 and 2. Shell transversely elongate, short in front of the beaks, elongate and narrowing behind them to the posterior end; basal margin having a gentle sinuosity, there being a slight einargina- tion just behind the midlength ; front margin regularly rounded; dor- sal margin proper rather short ; postero-dorsal margin forming a long, convex, downward slope from the dorsal to the postero-basal margin, which latter margin is narrowly rounded; beaks depressed and placed near the front of the shell. A somewhat prominent, but not sharply defined, umbonal ridge extends from the beak of each valve to the postero-basal margin, giving a flattened space at the postero-dorsal por- tion of each valve. Surface marked only by concentric lines of growth. Length, 63 millimeters; height, 30 millimeters; thickness, both valves together, 23 millimeters. This species was collected by Dr. Hayden from the fresh- water Eocene strata, near Washakie Station, in Southern Wyoming. Another species, quite a large one, to which I have given the name of Unio Meekiij changing it from U. leai Meek, which name was pre- occupied, was obtained by Dr. Hayden from the Bridger Group of South- ern Wyoming. This form is yet known only by fragments and natural casts of the interior; but it is known to have been a large, plain shell *Expl. and Sur. West of the 100th Merid., vol. iv, p. 206, pi. XXII, fig. 12, a, b, c, andd. WHITE.] ANNOTATED CATALOGUE. 435 of transversely oval outline, and having the anterior portion rather short in front of the beaks.* • The remaining three species of Unio yet to be noticed are all of the simple elongate, or transversely oval form, so common among living representatives of the genus. The first is U. sJioslionensis White,t which is figured on Plate 28. Specimens of it have been found at various localities in Southern Wy- oming and the adjacent parts of Colorado and Utah, in the Wahsatch Gr.oup of fresh-water Eocene strata there. The next is U. washakiensis Meek,J which is figured on Plate 28, and which has a similar geographical range and geological position. It seems also to range upward into the Bridger Group. The third and last is U. haydeni Meek,§ which is represented on Plate 28. This species closely resembles U. shoshonensis in external form, but it is a thinner and more delicate shell, with a more slender hinge. It also comes from a different group of strata. It is not improb- able that U. haydeni is identical with the species that was described by Hall under the name of My a tellinoides.\\ For purposes of compar- ison Professor Hall's principal figure of that form is copied on Plate 28. Although there are fresh-water deposits of considerable extent in Western North America of later date than the Eocene Tertiary epoch which have furnished numerous vertebrate, and a few molluscan remains, no Uniones, and only a few other bivalve species, which are referred to Sphcerium, have been found in any of them. In a few instances, some Uniones have been discovered in certain Post-Tertiary deposits, but as they have all been referred to living species, they do not come within the scope of this article.fi • CYRENHXE. The geological history of the Cyrenida3 of North America, as it is at present known, begins with the earliest epoch of the Cretaceous; but it was no doubt actually introduced much earlier. The family has apparently never formed a very prominent feature of any molluscan fauna, either marine or non-marine, in any of the geo- logical periods, except that of the Laramie, since its introduction. In this period there was so extraordinary a development of the genus Cor- *This species is described, and a cast of one valve figured in An. Rep. U. S. Geol. Sur. Terr., for 1878, Part I, p. 43, pi. 19, fig. 1. Owing to the imperfection of all the specimens of this species that have yet been discovered, no figure of it is given in this article. t An. Rep. U. S. Geol. Sur. Terr., for 1878, Part I, p. 41, pi. 19, fig. 2. *An. Rep. U. S. Geol. Sur. Terr., for 1878, Part I, p. 42, pi. 19, fig. 3. § Simpson's Report Great Basin of Utah, p. 364, pi. 5, fig. 11. || Fremont's Rep. Oregon and N. California, p. 307, pi. iii, figs. 1 and 2. H For an interesting discovery of this kind, by Prof. John Collett, in Indiana, see 7th An. Report Geol. Sur. Indiana, p. 246. See also, on a following page, remarks on spurious and doubtful species. 436 NON-MARINE FOSSIL MOLLUSCA. bicula as to give an impression to the casual observer that the family then reached a culmination, but it was in reality a culmination of the genus Corbicula only. In the Cretaceous strata of the western part of the continent several species belonging to the Cyrenida3 have been discovered, all of which are referred to the genus Cyrena as distinguished from Corbicula.* Only two of these species, however, are regarded as coming within the scope of this article, because all the others are found to be associated with such forms as are regarded as indicating a marine habitat, while those two species are associated with non-marine forms. Although in the Cre^ tacious period the genus Cyrena was established with all its distinctive characteristics, as they are at present known, and was represented by several known species in the southern portion of North America, with one or two exceptions the genus has not been recognized in strata of any geological period since the Cretaceous. And again, although the genus Corbicula formed" so conspicuous a fea- ture of the fauna of the Laramie period, it is at present not known to occur in any North American strata of either earlier or later date than that period ; if we except the C. truncata of Prime, which is understood to be of doubtful authenticity. These facts are significant as regards the genetic history of the family, and show, among other things, that our knowledge of that history is far from complete. The earlier of the two non-marine fossil species of Cyrena that have just been referred to, is C. dakotensis Meek & Hayden3t which has al- ready been mentioned on a previous page as an associate of Margari- tana nebrascensis in strata of the Dakota Group in Southeastern Dakota. It is represented on Plate 4 by copies of Mr. Meek's original figures. The other species is Cyrena carletoni Meek,! which is represented on Plate 5, and which was discovered by Mr. Meek in the Cretaceous estuary deposit at Coalville, Utah, which has already been mentioned in connection with remarks upon Anomia propatoris. The only examples of this species that have been discovered are small and delicate, and it is probable that they are all young shells. Although the family Cyrenidse has evidently become well established in the estuary and marine waters of the Cretaceous period, at least by its typical genus Cyrena, it is in the strata of the Laramie Group, as be- fore stated, that we find evidence of its greatest development, especially as regards the genus Corbicula. Among the fossil forms of that genus which the Laramie Group has furnished, three sections or subgenera are recognized, two of which have become extinct. Beginning with the Bear Eiver beds of the Laramie Group, which are perhaps somewhat earlier than the other known portions of the group, *For remarks on these genera, by Mr. Meek, see U. S. Geol. Sur. Terr., vol. ix, p. 157. tU. 8. Geol. Sur. Terr., vol. ix, p. 159, pi. I, fig. 1. J An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, p. 20, pi. 12, flg. 16. WHITE.] ANNOTATED CATALOGUE. 437 we find in Southwestern Wyoming, and the adjacent parts of Utah, one species of Corbicula which is interesting as being the type of a section of that genus for which Mr. Meek proposed the subgeneric name of Ve- loritina* This species, which he described under the name of Corbic- ula ( Veloritina) durlceei, t is represented on Plate 8. Two species of Corbicula were described by Meek & Hayden from the Judith Eiver beds of the Upper Missouri Eiver region, under the names respectively of C. cyihtriformis and C. occidentalism which are repre- sented on Plates 22 and 23 respectively. The first-named species is referred to the typical section of the genus ; but the latter approaches -in form the type of the subgenus Veloritina. Both these species have also been obtained from Laramie strata of Bitter Creek Valley in Southern Wyoming. The form which was described by Meek from that region, under the name of C. bannister i, is regarded as identical with C. occidentalis.l This form is represented on Plate 17. Two other Laramie species of Corbicula were described by Meek & Hayden, from the Upper Missouri Eiver region, both of which are, how- ever, from the Fort Union beds. They are respectively C. nebrascensis and C. subelliptica, both of which are represented on Plate 20. The latter has been recognized in the Laramie strata of Colorado east of the Eocky Mountains. It was referred by Mr. Meek to his subgenus Lep- testhes.\\ It seems not improbable that C. nebrascensis is only a young example of C. cytheriformis, but as that question is not yet settled, the former is here treated as a distinct species as well as the latter. The Laramie strata east of the Eocky Mountains in Colorado, which were by Dr. Hayden designated as the Lignitic Group, have been found in several localities to be especially rich in Corbicula. A part of these species are referable to the typical section of the genus and a part to the subgenus Leptesthes. To the latter subgenus belong C. subelliptica Meek & Hayden, C. macropistha White, C. planumbona Meek, and C. cardiniceformis White ; fl all of which are figured on Plates 21 and 22. Since the last-named form was published numerous other examples have been discovered which make it probable that it should be regarded as a variety of C. fracta Meek. « Other published species found in the valley of South Platte, and its tributaries in Colorado, are C. cleburni and 0. obesa White,** which are figured on Plates 20 and 23 respectively. *See U. S. Geol. Sur. Terr., Vol. ix, p. 161, for a diagnosis of this subgenus. tU. S. Geol. Sur. 40th parallel, vol. iv, p. 167, pi. Ivi, fig. 6. t U. S. Geol. Terr., vol. ix, pp.520, 521, pi. 40, figs. 5 aud 6. Also, An. Rep. U.S. Geol. Sur. Terr, for 1878, Part I; pp. 74, 75, pi. 21. $ See An. Rep. U. S. Geol. Sur. Ter. for 1878, Part I, p. 75. || For diagnosis of this subgenus, see U. S. Geol. Sur. Terr., vol. ix., p. 161. IF These species are described an.d figured in the An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I. References are also given there to original descriptions. ** See An. Rep. U. S. Geol. Sur. Terr, for 1878, part I, pp. 73, 73, pi. 23. 438 NON-MARINE FOSSIL MOLLUSCA. In addition to the six species last-mentioned, the three which are de- scribed in the following paragraphs for the first time, have been discov- ered in the Laramie strata of South Platte Yaley, Colorado, since the former were published. Corbicula berthoudi (sp. nov.), Plate 21, figs. 1, 2, and 3. — Shell very large, subtrigonal in marginal outline, moderately gibbous: front concave immediately in front of the beaks 5 front margin regularly rounded; basal margin broadly rounded; postero-basal margin ab- ruptly rounded up to the postero-dorsal margin, which latter margin slopes obliquely downward with a gentle convexity from between the beaks; hinge strong; all the teeth well developed, the lateral ones espe- cially being long and large and crenulated upon their edges, as is usual with all the known species of Corbicula of the Laramie Group; muscu- lar and pallial impressions having the usual characteristics; surface marked with the usual concentric lines. Length of one of the largest examples in the collections, 62 millime- ters; height from base to umbo, 54 millimeters; thickness, both valves together, 44 millimeters. This fine large species, the largest yet known in North America, has been found only in the Laramie strata east of the Eocky Mountains in Colorado. It is named in honor of Capt. E. L. Berthoud, the first dis- coverer of the rich shell deposits of the Laramie Group in that region. Corbicula augheyi (sp. nov.), Plate 21, figs. 4, 5, and 6. — Shell moder- ately large, sub-tetrahedral in marginal outline, postero-dorsal region not flattened, as in C. berthoudi; umbones full, rounded, considerably elevated above the hinge-line, front regularly rounded; basal margin broadly convex; posterior end truncated, the direction of the truncated margin usually a little backward of a line drawn perpendicularly with the base of the shell; postero-dorsal margin a little convex; hinge well developed; muscular and pallial markings of the usual character; sur- face marked by the usual concentric lines of growth, and usually by very faint umbonal ridges extending from the umbo to the postero- dorsal and postero-basal margins respectively upon each valve. Length of an adult example, 46 millimeters; height from base to um- bones, 38 millimeters; thickness, both valves together, 30 millimeters. This species has yet been found only in the valley of South Platte Eiver, in Northern Colorado, east of the Eocky Mountains. It is named in honor of Prof. Samuel Aughey, of Nebraska State University, who assisted me in the collection of the type specimens. Corbicula umbonella* Meek; Plate 21, Figs. 7, 8, 9, and 10.— Shell resembling C. obesa White, in most respects, but it is proportionally longer, the umbones are fuller and more elevated, and upon the pos- terior portion there are upon each valve two or three indistinct radiat- ing rugae. Upon other parts the surface is more than usually smooth. "See Boll. U. S. Geol. Sur. Terr., Sec. Ser., No. 1, p. 44, where this species is named but not described. WHITE.] ANNOTATED CATALOGUE. 439 Length, 39 millimeters ; height from base to umbones, 34 millimeters; thickness, both valves together, 26 millimeters. The large series of examples of all the described species of Corbicula that have been obtained from the Laramie strata east of the llocky Mountains in Colorado give unmistakable indications of genetic rela- tionship between them. It has already been stated that C. cardinice- formis is perhaps only a variety of C.fracta; and it may be remarked that C. obcsa, C.umbonella,guid. C. augJieyihold similar relation^ to each other. It is not unlikely that when all the CorbiculaB of the Laramie Group come to be fully studied, some of the species heretofore described must be abandoned ; but in an article like this, it is thought best to make mention of, and to figure, all the forms that have been published by any author, as he has published them. The species which Mr. Meek adopted as the type of his subgenus Lep- testheSj namely, C. (L.)fmcta* Meek, has been found in considerable abun- dance at Black Buttes station, in Southern Wyoming, and sparingly also at other localities on both sides of the Rocky Mountains. It is figured on Plate 20. This is the largest species of the subgenus Leptesthes yet known, and with the exception of C. berthoudi, herein described, the largest species of Corbicula that has ever been discovered in North American strata. The figures that are here given show it to be a very variable species as regards external form. Fig. 1, on Plate 20, is a copy of Mr. Meek's drawing from his type specimen. The partial truncation of the poste- rior border is a slight deformity of that specimen, and is not common to the species. The dimensions of that figure are also somewhat less than the average for adult shells. Figs. 4 and 5, on Plate 20, represent two views of a young example of ordinary form, but some examples of this species are more elongate transversely. No examples of the genus Sphcerium have been found in any North Amer- ican strata of older date than the Laramie Group, and none have been published from that group except the four species which were obtained by Meek & Hayden from the Upper Missouri Eiver region, and de- scribed by them respectively under the names Sphcerium planum, 8. rec- ticardinale, S. formosum, and S. subellipticumj These four species are all represented on Plate 17 by copies of Mr. Meek's original figures. The two first-named species are from the Judith Eiver beds, and the other two from the Fort Union beds. Some fragments of a species of Sphcerium, which is perhaps different from either of the four species above referred to, have been discovered in the coal-bearing beds at Evanston, Wyom- ing, which beds seem to belong to the upper part of the Laramie Group. A few imperfect examples, too imperfect for specific characterization, but evidently belonging to one or more species of the genus Sphcerium, * See U. S, Geol. Sur. Terr., vol. ix, p. 161. t See U. S. Geol. Sur. Terr., vol. ix,pp. 526, 527, pi. 43> 440 NON-MARINE FOSSIL MOLLUSCA. have been found in the Eocene fresh-water deposits of Southern Wyo- ming, which are, like those of the Laramie Group, so similar to certain living species as to call for no distinguishing remarks. We yet know nothing of the existence of Spliceriumin North America between the close of the Eocene epoch and the Post-Tertiary except the two species which were respectively described by Meek under the names Splicerium rugosum and 8. idahoense, both of which are represented, on Plate 32 by copies of his original figures. The types of these two species were obtained from the fresh- water deposit of the Kawsoh Mount- ains of Northern Nevada, which is regarded as of Miocene age by par- ties connected with the United States Geological Survey of the 40th parallel.* We do not yet know even so much as this of the history of the Unionidae between the close of the Eocene epoch and the beginning of the Post-Tertiary jt yet we cannot doubt that both Umo and Sphce- rium flourished together somewhere during all that time. PISIDIID^E. Of the genus Pisidium, only one fossil species, namely P. saginatum White, has yet been discovered.^ Its form is represented by figures 14 and 15, on Plate 20, and it is by its outward features alone that it is referred to Pisidium, the interior markings of the shell having never been ascertained. It was obtained from the series of coal-bearing strata near Evanston, Wyoming, which are at present understood as belonging to the upper part of the Laramie Group. While it seems to be unquestionable that the living Unionidse of the Mississippi drainage system are generically descended from those spe- cies which, as we have seen, existed during the Laramie period, and from their associates which yet remain to be discovered, no descend- ants of the CyrenidaB which then existed seem to have survived the close of the Laramie period, except those of the genera Sphcsrium and Pisidium. In fact, all three of the sections of the genus Corbicula. which have been mentioned as having lived during the Laramie period, seem to have required the same conditions of habitat that the contempora- neous Ostrea and Anomia did. When, therefore, at the close of the Lar- amie period, the waters of the interior region of North America became entirely fresh, all the forms of Corbicula which had flourished through- out that great region ceased to exist; while Sphccrium SLndPisidium, whose habitat is in fresh water only, survived to the present time, doubtless in company with representatives of the Unionida3, and with many fresh- water gasteropods. This opinion of course implies not only the belief that while the living Uuiones of the Mississippi drainage system are, either wholly or in part, directly descended from those whose remains *U. 8. Geol. Sur. 40th parallel, vol. iv, pp. 182, 183, pi. xvi, figs. 1 and 2. t That is, if we omit all those which are mentioned on following pages under the head of spurious and doubtful species. . t Powell's Report Geology of the Uinta Mountains, p. 128. WHITE.] ANNOTATED CATALOGUE. 441 we find in the strata of the Laramie Group, but also the belief that the brackish water Cyrenida3 which existed contemporaneusly with them in the Laramie period are not thus ancestrally related to the living species of Cyrena and Corbicula of North America, but that the latter have come down by some other lines of descent which are not yet known. CORBULIDJG. The genus Corbula is represented by several species in the Cretaceous strata of North America 5 but all the species that are yet known from strata of that period are found associated with marine forms] and, as they no doubt lived in marine water*, they do not fall within the scope of this article. Three or four species are known to have lived during the Laramie period, the faunal associates of which indicate a brackish water habitat 5 and as no other fossil species of this genus have been discovered under such circumstances as to make it probable that they lived in other than marine waters, we shall have only those Laramie forms to discuss at the present time. Nine species of Corbula have been described and named by different authors, from strata which have been studied at different localities, all of which strata are now referred to the Laramie Group; but at pres- ent I am disposed to regard less than half of them as distinct species, the remainder being regarded as at least no more than varieties of those species, respectively. Mr. Meek regarded all the Laramie species of Corbula as not belong- ing to the typical section of the genus; and he referred one of them to the proposed subgenus Anisorhynchus of Conrad, and the others to Pachyodon Gabb. In this article, however, I shall treat all the spe- cies herein discussed as true Corbula, without expressing an opinion as to the sections of the genus proposed by Conrad and Gabb; but it is proper to call attention to the fact that tho first two mentioned of the following species present a facies or type which is quite different from that of any living North American species of Corbula. Indeed, we may regard these Laramie forms as representing extinct lines of descent, for it is practically certain that the line of descent of none of the living species of Corbula has come down through any of those of the Laramie period as represented by the strata which we now know as the Laramie Group. The reasons for this opinion are expressed in the remarks that have been made in relation to the CyrenidiB of the Laramie Group, and the subject is further discussed in the remarks which close this article. Since the Bear Eiver beds are hypothetically regarded as the earlier portion of the Laramie Group, the first of the species of Corbula to be mentioned is C.pyriformis Meek,* which has been found only in those beds, and their equivalents in Southwestern Wyoming and the adjacent *See Simpson's Rep. Great Basin Utah, p. 361, pi. v, figs. 9 and 10. Also U. S. Geol. Sur. 40th Parallel, vol. iv, p. 170, pi. xvii, fig. 2. 442 NON-MARINE FOSSIL MOLLUSCA. parts of Utah. It is represented on* Plate 8. Mr. Meek described another form in connection with this under the name of C. englemannij but the numerous examples that have been collected from those strata show such a degree of variation as to make it very doubtful whether the difference between the two forms is anything more than individual variation. C. englemanni is therefore regarded as a synonym of C. pyriformis. An interesting species, which occurs in the valleys of Bitter Creek, Southern Wyoming, and Yampa River, Northwestern Colorado, was described by Mr. Meek under the name of Corbula undifera, which is illustrated on Plate 18. A .variety of this species, which also occurs in the valley of Bitter Creek, but at a higher horizon in the Laramie Group by several hundred feet, was described by me under the name of C. subundifera.* Although the latter is now regarded as only a variety of the former, yet the variation is quite constant and readily recognizable, as may be seen by comparing the figures of the . variety with those of the typical form on Plate 18. Two species were described by Meek & Hayden from the Judith River beds of the Upper Missouri River region, under the names re- spectively of Corbula subtrigonalis and C. perundata, both of which I regard as belonging to one and the same species. Furthermore, the two species which were described by Meek from the Laramie strata of the valley of Bitter Creek, Southern Wyoming, under the names re- spectively of G. tropidopJwra and C. crassatelliformis, I regard as also be- longing to that species, making three synonyms of (7. subtrigonalis.] Figures of these forms may be seen on Plate 19. One other published form of Corbula only remains to be noticed in this article, namely, C. mactriformis^. which was described by Meek & Hayden from the Fort Union beds of the Upper Missouri River region, and which has hitherto been found nowhere else. It is represented on Plate 18. The non-marine bivalve mollusca that have been noticed on the pre- ceding pages comprise only six families, while, as we shall see, their as- sociated gasteropod families were more than double that number. This numerical proportion of the families pertaining to the Conchifera and Gasteropoda, respectively, may be taken as about the same as that which obtains in those two classes among living non-marine mollusca. Indeed, the familieswhich have been recognized among these fossil forms are no other than those under which we group their living represen- tatives. *For descriptions and fignres of both these forms see An. Rep. U. S.-Geol. Sur. Terr, for 1878, Part I, pp. 80, 81, pi. 29. t For descriptions and fignres of these forms and remarks upon them see U. S. Geol. Sur. Terr., vol. ix, pp. 529, 530, pi. 40; An. Rep. U. S. Geol. Sur. Terr, for 1870, p. 315 ; ib. for 1872, p. 514 ; ib. for 1878, Part I, pp. 80, 81, pi. 25. t U. S. Geol. Sur. Terr., vol. ix, p. 528, pi. 42, fig. 7. WHITE.] ANNOTATED CATALOGUE. 443 Moreover, the majority of the genera, and many of the subordinate divis- ions of those genera, possess no recognizable variation from those under which we are accustomed to range the living species. We have, how- ever, seen that a small number of those subordinate types among the Conchifers have become extinct; and we shall see that still more of them among the Gasteropoda, together with a few of that class that we regard as full genera, have also become extinct; but yet the fact remains that these ancient non-marine mollusca, as a whole, are wonder&tlly like their living representatives.* GASTEROPODA. Although, in zoological rank, the gasteropoda are so much in advance of the Conchifera, the various families of the former seem to have been developed as early in geological time as those of the latter; and so far as we are now acquainted with the history of the fossil non-marine mollusca of North America, it appears that highly organized land pul- monate gasteropods were introduced quite as early as any of the Conchifers. Indeed, from present indications, we are led to believe that the relations of the different classes of non-marine mollusca to each other were much the same in all geological epochs as they are to-day. AURICULIDJ3. Three or four species of gasteropods have been discovered in the Cretaceous estuary deposits, and those of Bear Eiver, Laramie series, which are regarded as belonging to the family AuriculidaB ; and these are the only members of that family which have been discovered in North American strata, and the only ones that come within the scope of this article. One of these species was discovered by Mr. Meek in the Cretaceous estuary deposit at Coalville, Utah,t which has already been mentioned * There have been found in the Laramie Group two Conchifers and one Gasteropod which, so far as is now known, have living allies only in marine waters, and they are therefore not enumerated in this article, although they seem to have survived in the brackish water Laramie Sea from the time when it was an open sea of marine saltness. They are respectively Nuculana inclara, Axincea holmesiana and Odontolasis buccinoides White. With these exceptions, all the known molluscan species of the Laramie Group are such as we should naturally refer to some non-marine habitat. It is not at all im- probable that these species of genera which are usually characteristic of open-sea waters survived the land-locking of the Laramie Sea, and did not yield up their existence until the complete freshening of the waters took place, when their associates Cor&icuJa, Corbula, Neritina, &c., also ceased to exist. The species which was described by me as Odontobasis f formosa probably belongs to some genus of the Ceriphasiidae. For remarks upon the species referred to in this note, with descriptions and figures, see An. Rep. U. S. GeoJ. Sur. Terr, for 1878, Part I, pp. f>9, 60, 102, and 103 ; plates 20, 25, and 28. tAn. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, p. 23, pi. 12, tig. 11. 444 NON-MARINE FOSSIL MOLLUSCA. in connection with Anomia propatoris and Cyrena carletoni. It was originally described by Meek under the name of Melampus f antiqiius, but it is quite certain that it does not strictly belong to that genus. It is illustrated by several figures on Plate 5. An imperfect example of a similar and apparently congeneric form, which is represented by Fig. 17 on Plate 5 was found in the same neighborhood among the remains of marine Cretaceous mollusca, as was also an imperfect example of Physa; both of which specimens were no doubt drifted from the then adjacent shore, and sunk among the shells of marine mollusks that then lived there.* In the Bear River Laramie beds in Southwestern Wyoming there have been found two species closely related to the two that are referred to Melampus?, which, from their characteristics as well as their brackish- water faunal associations are referred to the Aurictilidse. They have considerable resemblance to Melampus? antiquus, and are possibly con- generic with it 5 but Mr. Meek proposed for them the generic name of RhytophorusA The first of these two species was discovered by Mr. Meek, and de- scribed by him under the name of Rhytophorus prisons ;$ and the second was described by myself under the name of R. meekii.% Both these forms are illustrated by figures on Plate 8. These three or four species constitute the only representatives of the Auriculidae that have yet been obtained from North American non-marine strata, and they are so remotely allied with living representatives of that family that we cannot regard them as holding such ancestral relation to any of the living North American Auriculida3 as the fossil Unionidae and some other families herein discussed, evidently hold to the living rep- resentatives of those families respectively. Indeed, for reasons already stated, it is practically certain that the lines of descent from such of the mollusca of the Laramie period as required a saline habitat were neces- sarily broken at the close of that period, when the waters of that sea became wholly fresh and greatly reduced in extent. LIMN2EID2E. The earliest North American strata in which remains of the Lim- nseidse have been discovered are those of the Laramie Group ; if we ex- cept the Jurassic form, which was described by Meek & Hay den under the name of Planorbis veternus, and which is presently to be further mentioned. In the Laramie Group, however, we find the, family repre- sented by all the principal genera that are known among the living Limnseidse, as well as the greater part of the subordinate sections of the * See An. Rep. U. 8. Geol. Stir. Terr, for 1878. , Part I, p. 25. Ib. for 1877, p. 307. t For diagnosis of this genus see U. S. Geol. Sur. 40th Parallel, vol. iv, p. 175. t U. S. Geol. Sur. 40th Parallel, vol. iv. p. 175, pi. xvii, fig. 6. Also Simpson's Rep. Great Basin, Utah, p. 3C4, pi. v, fig. 4. $ See An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, p. 82, pi. 30, fig. 8. WHITE.] ANNOTATED CATALOGUE. 445 genera which constitute that family. These facts necessarily point back to a period much more remote than the Laramie, for the origin of the family, and although we lack the positive evidence of the fact, we can- fiot doubt that it not only had its origin as early as the beginning of Mesozoic time, but that it had then become well established. The earliest known species belonging to the genus Limncea is L. niti- dula Meek,* which is found in the Bear River Laramie strata of South- western Wyoming. It is represented on Plate G. It is referred to the subgenus Limnophysa Fitzinger. Among its faunal associates is a minute form, which I. have described under the name of Acella lialde- manij which is represented by enlarged figures on Plate 6. Associated with these is also a small Planorbis, belonging to the sub- genus Gyraulus Agassiz. It is a fact which doubtless indicates the imperfection of our present knowledge that, while those two widely differentiated members of the Linmseida} are found in what are regarded as probably the earlier strata of the Laramie Group, the only other species which is referable to the subfamily Limna3ina3 that has been found in any part of that group is a form, which was described by Meek & Haytlen, from the Fort Union beds, under the name of Limncea tenuicostata. f Mr. Meek proposed for this form the subgeneric name of Pleurolimncea, but it might probably be referred to Acella with equal propriety. It is represented by a copy of Mr. Meek's figure on Plate 23. Although a greater number of the Planorbinae than of the Limnseinae have been discovered in the Laramie Group, the apparent absence of the latter from most of the fossiliferous strata of that group, even those which contain other palustral pulmonates, such as Pliysa and Bulinus, is unexpected, and, as before intimated, it is probably not because they did not exist, but because they have not been discovered. Mr. Meek de'scribed a species under the name of Limncea (Limno- pliysa?) compactilisfi from Separation Station in Southern Wyoming, which was obtained from strata that he regarded as Tertiary, but which doubtless belongs to the Laramie Group. It probably belongs to the genus Thaumastus, and not to Limncea. It is represented on Plate 26 by figures of Mr. Meek's type specimen. Mr. Meek described two species of Limncea, which he stated were dis- covered in the Bridger Group of Eocene fresh- water strata in Southern Wyoming. He named them respectively L. vetusta and L. similis.\\ Both these forms are represented by copies of Mr. Meek's figures on Plate 29. From the Green Eiver Eocene Group of Southern Wyoming I have *U. S. Geol. Sur. 40th Parallel, vol. iv, p. 181, pi. xvii, fig. 5. t An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, p. 84, pi. 30, fig. 9. tSee U. S. Geol. Sur. Terr., vol. ix, p. 534, pi. 44, fig. 13. $ An. Rep. U. S. Geol. Sur. Terr, for 1872, p. 517. || U. S. Geol. Sur. 40th Parallel, vol. iv, p. 191, pi. xvii, figs. 3 and 4. Also, Simpson's Rep. Great Basin, Utah, p. 3C7, pi. v, figs. 2 and 3. 446 NON-MARINE FOSSIL MOLLUSCA. described a species under the name of L. minuscula,* which evidently belongs to the subgenus Leptolimncea Swainson. It is represented on Plate 1:9. The species that have just been mentioned are all that are known tib have existed in North America up to the close of the Eocene epoch, which pertain to the comprehensive genus Limncea. The fresh-water strata, which are known as the White Kiver Group, and are referred to the Miocene Tertiary, are the onl j strata of that epoch which are at present known to contain any remains of Limncea. In that group two species of Limncea have been discovered, namely, L. meekii Evans & Shumard, and L. shumardi Meek.t Both of these species belong, apparently, to the typical section of the genus, and both are represented by copies of Mr. Meek's original figures on Plate 32. If the non-marine molluscan fauna, of the epoch of which the White River Group is a partial representative, were better known, it may be regarded as certain that we should find in it many representatives of living types; but so far as that fauna is at present known, it is a very meager one, and confined to the pulmonate gasteropods. The apparent entire absence of gill-bearing mollusks in those portions of that forma- tion which have been examined, may, perhaps, have been due to a solu- tion in the waters in which they were deposited, of certain salts or other substances which made them uncongenial for molluscan life. If this were really the case, the presence there of the remains of pulmonate gaster- opods might be accounted for on the supposition that they were drifted into those waters by tributary streams in or upon the banks of which they lived. The only other species of Limncea to be mentioned in this article is the one which was described by Mr. Meek under the name of L. Icingii, and for which he proposed the subgeneric name of Polyrliitis.\ It was obtained from certain strata in Cache Valley, Utah, which are not of earlier date than the Miocene, and which are probably of Pliocene age. Copies of Meek's original figures of this form are given on Plate 32. It is an interesting form because of the fact that it is the only known representative of the only extinct subordinate type of Limncea that is yet known, and because it comes down to a later date than most of the other extinct types of mollusca, of which mention is made in this article. Of the other genera of the family Limnreidse, Planorbis and Carinifex, remain to be considered. The earliest species of Planorbis yet discovered in North American strata is P. veturnus Meek & Hayden, § which those *Proc. U. S. Nat. Museum, vol. iii, p. 1GO. t For descriptions and figures of these two species see U. S. Geol. Sur. Terr., vol. iv, pp. 598 and 599, pi. 45, figs. 5 and 6. JFor description and figures of this species see U. S. Geol. Sur. Terr., 40th parallel, vol. iv, p. 192; and for Meek's diagnosis of the subgeuus see U. S. Geol. Sur. Terr., vol. ix, p. 532. $ Paleontology of the Upper Missouri, p. 107, pi. iv, fig. 1. WHITE.] ANNOTATED CATALOGUE. 447 * authors reported as coming from Jurassic strata in the vicinity of the Black Hills, where they found it associated with Unio nucalis and other species, which have already been referred to. It is represented on -Plate 3. It cannot be doubted that various species of Planorbis existed during the whole of the Cretaceous period, but no evidence of the fact has yet been obtained. In the Bear Eiver Lararnie beds, however, a small, un- described species is known, as already mentioned, which belongs to the subgenus Gyraulus. In the Laramie period the genus PlanorMs is believed to have flour- ished; not because many examples have been found in those strata, but because the examples which have been discovered indicate that the dif- ferent species which they represent reached a wide range of differen- tiation. Meek & Hay den described Planorbis convolutus* from Laramie strata, in the Upper Missouri liiver region, which they regarded as of the age of the Judith Eiver beds. This species seems to be referable to, or, not widely different from, the typical section of the genus as it is known among living forms. It is represented on Plate 27. The subgenus Bathyomphalus Agassiz, although not known to be now living in North America, is represented by three species in the Laramie Group ; but it has not been recognized in any strata that are referred to a later date. One of these species was obtained from the Judith Eiver beds, and was described by Meek & Hay den under the name of PlanorMs (Bathyomphalus) amplexus ; t and the other, by the same authors, from the Fort Union beds, under the name of P. (B) planoconvexus.$ Still another species, obtained from the Laramie strata of Southern Utah by Professor Powell, was described by myself under the name of Planorbis (Bathyomphalus) kanabensis.§ All three of these forms are represented on Plate 27. Besides the species of Gyraulus that has already been mentioned as existing in the Bear Eiver Laramie beds, another was obtained by one of the parties under the direction of Lieutenant Wheeler, from strata that belong to either the upper part of the Laramie Group, or the lower portion of the Eocene. This species I have described under the name of Planorbis (Gyraulus) militaris.\\ It is illustrated on Plate 28. A fine large species of Planorbis was described by Mr. Meek from the Bridger Group of Southern Wyoming, under the name of P. utahensis, and also a variety of the same under the name of P. spcctabilis.H Both these forms are illustrated on Plate 29. * U. S. Geol. Sur. Terr., vol. ix, p. 536, pi. 43, fig. 11. t U. S. Geol. Sur. Terr., vol. ix, p. 539, pi. 42, tig. 16. t U. S. Geol. Sur. Terr., vol. ix, p. 538, pi. 44, fig. 9. § Powell's Rep, Geology of the Unita Mountains, p. 119. || Proceedings U. S. National Museum, vol. iii, p. 159. If For Meek's descriptions and figures of these two forms see U. S. Geol. Sur., 40th Parallel, pp. 189, 190, pi. xvii, figs. 13 and 14 ; Simpson's Eep. Great Basin, Utah, pp. 266, 267, pi. v, figs. 6 and 7. Also see Expl. and Sur. West of 100th Merid., vol. iv, p. 209, pi. xxi, fig. 8, for description and figures by White. 448 NON-MARINE" FOSSIL MOLLUSCA. » This species is similar in outward form to those which have been grouped under the subgeneric name of Gyraulm; but in size it is very much greater than any of the species which have been referred to that subgenus. A species somewhat similar to the last, but smaller, more nearly discoid in form, and having much more slender volutions, was obtained by my- self from the Green Eiver Group of Southern Wyoming, and described « under the name of Planorbiwirratus.* It is illustrated on Plate 29. From the same region and from the same formation I also obtained Plan- orbis ceqiialis White, f which is illustrated on Plate 29. It seems to possess all the characteristics of the typical section of the genus. From the fresh-water strata that are referred to the Miocene epoch, only four species of Planorbis have yet been published, which, being the only known fossil species of that genus of later date than the Eocene, are the remaining species to be noticed in this article. Three of these are described by Meek & Hayden from the White River Group in Dakota, under the names respectively of Planorbis vetustus, P. leidyi, ajid P. nebrascensis.\ They. are illustrated on Plate 32. The remaining species § was described by T. A. Conrad, under the name of P. lunatus, from "Bridge Creek, Oregon," where it was found associated with Zonites marginicola* mentioned on a following page. Copies of Conrad's figure are given on Plate 32. Eeference has already been made, in connection with a notice of Sphce- rium rugosum and S.f idahoense, to two deposits similar to each other in their faunal contents, the one being found in the neighborhood of the Kawsoh Mountains, in Northern Nevada, and the other in Southern Idaho, which are regarded as of Miocene age. These strata have fur- nished a limited but interesting molluscan fauna, among the species of which are two that were described by Meek under the names respect- ively of Carinifex (Vorticifex) tryoni and C. (V.) binneyi.\\ Both these forms are illustrated on Plate 32. Although, as has already been shown, the family Limna3ida3 (to which Carinifex is here referred) flourished ever since Mesozoic time, no otner fossil species of Carinifex have yet been found in strata of any age, and no representatives of that genus, are now known to be living in North America except a few upon the Pacific slope. If the Miocene lake, tne deposits of which contain the two species of Carinifex which have just been noticed, had drained into what is now the hydrographic basin of the Mississippi, representatives of that type as well as those of its asso- ciate mollusca would no doubt now be found living there. But as the * Au.JRep. U. S. Geol. Sur. Terr, for 1878, Part I, p. 44, pi. 19, fig. 5. t Proceedings U. S. Nat. Museum, vol. iii, p. 159. \ For descriptions and figures of these three species by their authors, see U. S. Geol. Sur. Terr., vol. ix, pp. 600, 601, pi. 45, figs. 1, 2, and 3. $ Am. Jour. Conch, vol. vi, p. 315, pi. 13, fig. 8. II U. S. Geol. Sur. 40th Parallel, vol. iv, pp. 187, 188, pi. xvii, figs. 11 and 12. WHITE.] ANNOTATED CATALOGUE. 449 type referred to is found among the living mollusca in Pacific drainage waters, it may be fairly inferred that that Miocene lake was drained into western and not eastern oceanic waters. It should be remarked, however, that no representatives of some of the types which were asso- ciated with those ancient forms of Carinifex are now known to be living. PHYSIIXE. The Physidae have been found to be comparatively well represented in nearly all the strata which have furnished any fossil pulmonate mol- lusca. Both Physa and Bulinus are represented by several species (all of which are regarded as extinct), ranging from the Cretaceous to the Miocene, inclusive. Notwithstanding their great antiquity, there seems to be among them all very little deviation from the types which are expressed by the numerous living species of those genera. The earliest known species referable to the Physidse is Physa carletoni Meek,* which was obtained by him from the Cretaceous estuary deposit at Coalville, Utah, which has before been referred to in connection with Anomia propatoris, Cyrena carletoni, and Melampus f antiquiis. P. carle- toni is represented by a figure on Plate 5. In many cases the earliest known species of a genus which is capable of subdivision into subordinate types or sections is not referable to that section which has been selected by naturalists as the typical one; but in the present case Physa carletoni seems to be a typical Physa, while some of the later species seem to depart more from the typical form. These facts are, however, of no great significance, because the section of a genus which is designated as typical is usually only conventionally selected; and, also, because we cannot know with certainty whether the earliest known species was in reality the earliest. Although only the one species just mentioned has yet been discovered in any strata of greater age than those of the Laramie Group (if we except a fragment which has been found in the marine Cretaceous strata at Coalville, Utah, and which was probably drifted to that position from the then adjacent shore t), we cannot doubt that the Physidse were comparatively abun- dant in the Cretaceous period, because that species is so unmistakable in its generic characteristics, and also because it belongs to a type that has reached the present time unchanged. An unnamed form, which is probably a true Physa, has been found in the Bear River Laramie beds of Southwestern Wyoming, a figure of which is given on Plate G.f Plate 25 contains figures of a fine large species which Professor Cope obtained from the Judith Eiver Laramie beds in the Upper Mis- *An. Rep.U. S. Geol. Sur. Terr, for 1877, p. 306, pi. 7, fig. 12. t U. S. Geol. Sur. Terr, for 1877, p. 307, pi. 7, fig. 13. The figure is also given on Plate LXV, accompanying tliis article. t An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, p. 85, pi. 30, fig. 11. 29 a 450 NON-MARINE FOSSIL MOLLUSCA. souii Eiver region, and which I described under the name of Physa copei.* Some fragments of a Physa have been found in the Caramie strata of Crow Creek Valley in Colorado, east of the Eocky Mountains, that indi- cate a somewhat remarkable and interesting form. It was described by me under the name of Physa felix. t The best example yet discovered is figured on Plate 25. A species which occurs in the Wahsatch Group of Eocene strata in Southern Wyoming and adjacent parts of Colorado and Utah, and which reaches a greater size than any other known fossil Physa, perhaps excepting P. copei, has been described by myself under the name of P. pleromatis.\ The type specimen of the species is figured on Plate 30. Some imperfect specimens have been found in Colorado, apparently be- longing to this species, that indicate a very much greater size. A par- tially restored figure of one of these is given on Plate 30. Another fine species has been described by Meek from the Bridger Eocene group of Southern Wyoming, under the name of Physa Iridger- ensis.% It is illustrated on Plate 30. Physa pleromatis is apparently a typical Physa , but P. bridger cnsis perhaps ought to be referred to Bulinus. For present convenience, however, it is referred to Physa. From the Miocene White Eiver Group of Dakota, Evans & Shumard described Physa secalina,\\ which is represented on Plate 32. It has a very modern aspect, although it is regarded as an extinct species, No fossil Physa of later age than this has yet been published from any North American strata, but one or more species is known to exist in certain strata of Southern Wyoming and Northwestern Colorado, which Professor Powell has named the Brown's Park Group, and are probably of Pliocene age. The genus Bulinus is well represented in the Laramie Group, but no other species of that genus has yet been published from any other Noith American strata, unless Physa bridgerensis should prove to be a Bulinus, as already suggested. Associated with Physa copei in the Judith Eiver Laramie beds, Professor Cope found a fine large species of Bulinus which I described under the name of B. atavus.^\ It is figured on Plate 25. From the Laramie strata, at the mouth of Judith Eiver, Meek & Hay den obtained the type specimens of Bulinus subelongatus ; ** which is represented on Plate 25. From the Fort Union Laramie beds two other specimens of Bulinus * An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, p. 84, pi. 22, fig. 1. t An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, p. 84, pi. 22, fig. 1. JExpl. and Sur. West of the 100th Merid., vol. iv, p. 211 ; pi. xxi, fig. 1. $ An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, p. 45, pi. 19, fig. 10. U U. S. Geol. Sur. Terr. vol. ix, p. 604, pi. 45, fig. 4. If An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, p. 86, pi. 24, fig. 5. ** U. S. Geol. Sur. Terr., vol. ix, p. 540, pi. 42, fig, 13. WHITE.] ANNOTATED CATALOGUE. 451 were described by Meek & Hayden, under the names respectively of B. longiusculus and B. rhomboideus,* both of which are represented on Plate 25. These two forms are so closely like Physa that they may apparently be with equal propriety referred to that genus. Indeed if these two species are properly referred to BuUnus, then Physa bridger- ensis and one or two other species herein referred to Physa ought to be referred to Bulinus also. • In the Laramie strata, east of the Rocky Mountains, in Colorado, Bu- linus disjunctus White,! occurs. It is represented on Plate 25. Another Laramie species was discovered in Southern Utah by Pro- fessor Powell, which I described under the name of Physa kanabensis, { but which ought to be referred to Bulinus. This species is yet known only by specimens that are too imperfect for satisfactory illustration. ANCYLID.E. The Ancylidoe, when present, always form an inconspicuous feature in any fresh-water fauna, and the family is represented by only two published species, so far as is now known, in all the North American strata. One of these species, Acroloxus minutus, Meek & Hayden, was obtained by them from the Laramie strata near Fort Union, in the Up- per Missouri Eiver region.§ It is illustrated on Plate 24. The other fossil representative of the family is Ancylus undulatus, Meek, 1 1 from the Miocene deposit of the Kawsoh Mountains of Northern Nevada, where it was found associated with the two species of Curinifex that have already been mentioned, and also with certain other fresh- water forms. It is represented on Plate 32. In the Southern Idaho equivalent of the Eocene beds just mentioned, associated with Melania taylori, Lithasia antiqua, Sphcerium rugosunij &c., an interesting shell has been found which seems to agree with the genus Latia Gray, although that genus has hitherto been known only in certain portions of Oceanica, and only in the living state. This form may be briefly characterized as follows : Latia dallii (sp. nov.), plate 32, figures 37, 38, 39, and 40. Shell sub- ovate in marginal outline 5 irregularly convex above ; the posterior por- tion narrowing rapidly to a small prominent umbo, which ends in a very small, closely-incurved beak; the beak turned a little to the right side, and making about one full volution; semilunar shelf or septum comparatively large. Surface marked by many strong, irregular, con- centric undulations ; but otherwise it is comparatively smooth, being marked only by fine lines of growth. *U. S. Geol. Sur. Terr., vol. ix, pp. 541,542, pi. 43, figs. 16 and 17. t An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, p. 86, pi. 24, fig. 6. t Powell's Rep. Geology of the Uinta Mountains, p. 119. § U. S. Geol. Sur. Terr., vol. ix, p. 543, pi. 44, fig. 10. || U. S. Geol. Sur. 40tli Parallel, vol. iv, p. 188, pi. xvil, fig. 12. 452 NON-MARINE FOSSIL MOLLUSCA. Length, 16 millifneters; breadth, 10 millimeters 5 height, 7 millimeters. The specific name is given in honor of Mr. W. H. Dall, whose impor- tant works upon the mollusca are well known. VITRINIDJE. It is a suggestive fact that so large a proportion of the fossil non- marine mollusca, which have been found in North American strata, are air-breathing land snails. This result of field-investigation is unex- pected, both because individuals of none of the living land-snails are. found in as great numbers as many of the gill-bearing water snails are, and because all the specimens that have been preserved in the fossil state must have been transported from the land into the waters in the sediments of which they were preserved after the death of the mollusks which formed them. We must therefore conclude that in former geo- logical epochs the land-snails were proportionally quite as abundant as they are now, and it seems probable, also, that the shores of, and the region round about, the Laraime sea, and those of the great fresh-water lakes which succeeded that sea, formed a peculiarly favorable habitat for land mollusca. Judging from the character of a portion of the fossil shells that have been discovered, and from the wide diversity in the families of land mol- lusca, which is indicated by the collections that have been made from various formations, we cannot doubt that the family Vitrinida3 was represented, at least during the Laramie and Tertiary periods. It is not to be denied, however, that with a knowledge of the shells only, and they usually more or less imperfect, it is not always possible to say with certainty that those which we refer to that family really belong to it ; or that they may not belong to the Helicidse. The three following-named species were described by Meek & Hay- den, and referred by them, not without some doubt, to the Vitrinidae. They obtained them from the Judith Eiver Laramie beds of the Upper Missouri River region, and named them respectively, Vitrinaf obliqua, Hyalina? occidentalis, and H.f evansi.* All three of these forms are represented by figures on Plate 27. From the Wind Eiver Group of Eocene strata, in Wyoming, Meek & Hay den also obtained a fine large species, which they described under the name of Macrocydlis spatiosaj which is represented on Plate 30. ARIONID2E. Among the most interesting remains of land mollusca that have been discovered are those which Dr. J. W. Dawson has published at different times from the Coal-Measures of Nova Scotia. He was the first to demou- * U. S. Geol. Sur. Terr. vol. ix, pp. 545-548, pi. 42, figs. 6 and 7. tU. 8. Geol. Sur. Terr., vol. ix, p. 594, pi. 42, fig. 9. ANNOTATED CATALOGUE. 453 strate that a widely differentiated land molluscan fauna existed during the Coal Measure period, if not much earlier. . If the species which Dr. Dawson described under the name of Zonites prisons , * from the Coal Measure strata of South Joggins, ISTova Scotia, is really a Zonites, or a closely related form, we have proof of the remark- able fact that the family Arionidae was well established in the Carbon- iferous age. The correctness of the reference of this species to the Arionida3 being accepted, we naturally conclude that other members of the family have existed somewhere during all the time that has 'elapsed since the Carboniferous age; but yet remains of no other representa- tives of the Arionida3 are now known to exist in any North American strata., if we except the one mentioned below. Copies of Dr. Dawson's original figures of Zonites prisons are given on Plate 2. His specimens were found associated with Pupa vetmta and P. bigsbyi Dawson, both of which species are mentioned in their order on following pages. Mr. T. A. Conrad published a form under the name of Helix (Zonites) marginicolaj from Bridge Creek, Oregon, which probably comes from a fresh-water Eocene deposit. His specimens seem to have been very im- perfect and unsatisfactory. A copy of his figure is given on Plate 32. HELICIDJE. Among other molluscan remains that have been discovered in the Coalmeasure strata of Indiana and referred to the Pulinonata is a form to which Professor Bradley gave the generic name of Dawsonella? describ- ing the species under the name of D. meekii.\ Dr. Dawson, in comment- ing upon this form, expresses the opinion that it belongs to the Helicidae "near Helix (Triodopsis) palliata and H. (Stenotrema) monodon;"§ but Professor Whitfield expresses the opinion that it was an operculate shell resembling Helicina.\\ For present convenience, and without reference to the merits of the question raised, this species is here left where Dr. Dawson first placed it. It is in either case very probable that true members of the Helicidse really did exist during the Coalmeasure epoch, contemporaneously with the Pupida3 which are known to have existed then, and which are pres- ently to be mentioned. Dawsonella meekii is represented on Plate 2 by copies of Professor Whitfield's figures. If Dawsonella should prove not to belong to the Helicidae, the earliest examples of that family which are yet known to occur in North Ameri- can strata are found in the Laramie Group. From the Judith Eiver Laramie beds of the Upper Missouri region Meek & Hayden obtained two species which are referred to this family. The first they described *Am. Jour. Sci., vol. xx (3), p. 411, figs. 10 and 11. tAm. Jour. Conch., vol. vi, p. 315, pi. 13, fig. 9. JAm. Jour. Sci., vol. iv (3), p. 88. $ Am. Jour. Sci., vol. xx (3), p. 413. || Am. Jour. Sci., vol. xxi (3), p. 127. 454 NON-MARINE FOSSIL MOLLUSCA. as Helix vetusta, and the other under the name of Thaumastus limnccfor- mis;* the first being represented on Plate 27 and the latter on Plate 25. The former is perhaps not a typical Helix, but the latter is probably a true representative of Thaumastus, as that genus is known among living mollusca. If so, it is the only fossil representative of the section of the Helicidae to which it belongs that is at present known in North America strata (if- we except the Bulinus floridanus of Conrad from the Eocene of Florida and perhaps also the species mentioned on page 445 under the name of Limncea(Limnophysaf) compactilis, although living species of Thaumastus are not uncommon in the southern part of North America. . From the Fort Union Laramie beds of the Upper Missouri Eiver region Meek & Hayden also described two species of HelicidaB under the names respectively of Columna teres and C. vcrmicula.] These also are the only representatives of their genus that are yet known in North Ameri- can strata, and, like the next preceding species, no living congeners are found in North America so far northward as the localities from which the fossil species were obtained. Both these forms are represented on Plate 25. From the Laramie strata of Southern Utah Professor Powell obtained a species of Helix that seems to possess the characteristics of the sub- genus Strobila Morse, and which I have described under the name of Helix Tcanabensis.\ It is figured on Plate 25. It was found associated with Physa Jcanabensis and Planorbis (Bathyomphalus) Jcanabensis, bpth of which have already been noticed. A series of coal -bearing strata near Evanston, Southwestern Wyoming, which apparently belong to the upper part of the Laramie Group, have furnished a number of species of pulmonate mollusca, among which are two species of Helix, namely H. Sepulta and H. evanstonensis White.§ The former seems to possess the subgeneric characteristics of Patula Haldeman, and although its characteristics have been quite clearly ascertained, the specimens are all too imperfect for figuring. H. evans- tonensis is apparently referable to the subgenus Triodopsis Eafinesque. It is figured on Plate 27. From the Wind Eiver Group, a series of fresh- water Eocene strata in Western Wyoming, a fine species was obtained by Meek & Hayden and described by them under the name of Helix f veterna.\\ It is repre- sented by copies of Mr. Meek's figures on Plate 30. Certain charac- teristics presented by this shell cause some doubts* to arise as to its real * For figures and descriptions of both these species see U. S. Geol. Sur. Terr., vol. ix., pp. 552, 553, pi. 42, fig. 7; and pi. 44, fig. 8. tU. S. Geol. Sur. Terr., vol. ix, pp. 555, 556, pi. 44, figs. 11 and 12. t Powell's Rep. Geology of Uinta Mountains, p. 120. $The first of these species was originally described in Proc. IT. S. Nat. Museum, vol. iii, p. 160; and.tho other in Bull U. S. Geol. Sur. Terr., vol. iv, p. 714. IU. S. Geol. Sur. Terr., vol. ix,p. 596, pi. 42, fig. 8. WHITE.] ANNOTATED CATALOGUE. 455 affinities ; but it is at present left with the Helicidae, where those au- thors placed it. Professor Powell obtained from the Bitter Creek Group, in Central Utah, the earliest of the fresh- water Eocene series, a species which I described under the name Helix peripheria,* and which appears to pos- sess the subgeneric characteristics of Aglaia Albers. From the Eocene Green Eiver Group of Southern Wyoming he also obtained H:riparia\ White, which is apparently referable to the subgenus Arianta Leach. Both the last-mentioned species are figured on Plate 29. Whether Helix Jcanabensis, H. sepulta, H. evanstonensis, H. peripJieria, and H. riparia are correctly referred to the respective subgenera in con- nection with which they have just been mentioned, or not, their diversity of form gives sufficient indication that the Helicida3 had become widely differentiated during those early epochs in which they lived, probably quite as widely as their living representatives are, and under closely similar forms. At present, the only known Miocene species of Helix is H. leidyi Hall & Meek; which is also the only known fossil species of that genus of later date than the Eocene.§ It is represented on Plate 32. PUPUXE. If it were not that the existence of a diversified land molluscan fauna during the Coal-Measure period is a well-established fact, we should be slow to accept the conclusion of Dr. Dawson that the shell which he has described from the Erian (Devonian) plant-beds of St. Johns, New Brunswick, under the name of Str ophites granclceva§ is really a land snail. In view of the fact just stated, and of the reasons which he gives for his conclusions, we seem to have no reason to doubt that the shell in question is, as he suggests, closely related to Pupa. A copy of his figure of it is given on Plate 1. Although an unexpectedly large number of species of non-marine mollusca has been obtained from strata so ancient as those of the Coal- Measures, the fact that the Gasteropoda are all land snails shows clearly that the complete non-marine mollusca of that period is very far from being fully known. It cannot be supposed that coordinate families, similar to those with which representatives of the species referred to are raneously with those ancient species which have been discovered. The known to have been afterwards associated, did not exist contempo- continental area, however, having been at that time smaller than it afterward became, the rivers were necessarily comparatively few and small. Therefore, the fresh-water mollusca, as compared with those of the land, were perhaps proportionally fewer then. * Powell's Rep. Geology Uinta Mountains, p. 130. t/Wd. I See mention of some California species of Helicidso found in a fossilized condition* under-thc head of spurious and doubtful species, on a following page. §Ain. Jour. Sci., vol. xx (3), p. 413. 456 NON-MARINE FOSSIL MOLLUSCA. Among the non-marine mollusca which have been discovered in the Coal-Measure strata of Canada and the United States are four species which belong to the Pupidse. Dr. Dawson was the first to recognize the pulmonate character of these mollusks, and he described the first- discovered species under the name of Pupa vetusta, the type specimens of which he obtained from the Coal Measure strata at South Joggins, Nova Scotia.* Copies of his figures of this species are given on Plate 2. Professor Bradley described P. vermillionensisl from the Coal-Measures of Indiana, and subsequently Dr. Dawson described a second spe- cies under the name of P. Mgsbyi\ from the same strata and same locality in Nova Scotia that had furnished examples of P. vetusta. Both these species are represented by copies of Dr. Dawson's figures on Plate 2. Within the present year (1881) Professor Whitfield has described a fourth Pupa-like form from the Coal-Measure strata near Marietta, Ohio, for which he proposed the new generic name of Anthraeopupa, describ- ing the species under the name of A. ohioensis.§ Copies of Professor Whitfield's figures are given on Plate 2. Whether the species described as Pupa by Dawson and Bradley strictly belong to the typical forms of that genius, as it is represented by living species, or not, there seems to be no room for reasonable doubt that all four of the Carboniferous forms that have just been noticed belong to the family PupidaB. This being the case, it cannot be doubted that the family was well represented during all subsequent epochs 5 and yet no other fossil species besides these have been discovered in North American strata, except those which have been found in the fresh-water Eocene deposits of Southern Wyoming. One of these Eocene species was described by Mr. Meek, from the Bridger Group, in Southern Wyoming, under the name Pupa? leidyi.\\ The type specimen of this species seems to have been lost,- and there- fore no figure of it can be given. It evidently differed considerably from the typical forms of Pupa, and Mr. Meek was in doubt whether it might not with propriety be referred to Holospira Albers. The remaining three species of the Pupidoe to be noticed in this article were all obtained from the Green Eiver Eocene Group at one locality, in Southern Wyoming. They have been published under the following names, respectively : Pupa incolata, P.arenula, and P. atavuncula White.ff The first-named species seems to belong to the subgenus Leucocheila 'Acadian Geology, 1855, p. 160 ; Am. Jour. ScL, vol. xx (3), p. 405. t Am. Jour. Sci., vol. iv (3), p. 87. i Am. Jour. Sci., vol. xx (3), p. 410. $ For generic diagnosis and specific description see Am. Jour. Sci. vol. xx (3), p. 126. II An. Rep. U. S. Geol. Sur. Terr., for 1872, p. 517. IF For descriptions and figures of these three species, see An. Rep. U. S. Geol. Sur. Terr., for 1878, Part I, pp. 4(5, 47, pi. 19, figs. 7, 8, and 9. WHITE.] ANNOTATED CATALOGUE. 457 Alb. & Mart. ; and the other two are referred provisionally to Pupilla Leach. All three of these forms are represented on Plate 29. Owing to the imperfection of the type specimens of these three species, their reference to the subgenera which have just been mentioned is not made with entire confidence ; but whether this reference is correct or not, it is a well-established fact that the family Pupidse had acquired, as early, at least, as the earliest Eocene, nearly or quite all the characteristics which distinguish it at the present day. 8UCCIN1D2E. Although so large a number and great variety of other land-snails have been discovered in the strata of various geological periods, only a single species referable to the Succinidse has yet been found in North American strata. This is succinea papillispira, White,* which was ob- tained from the upper portion of the Green River Eocene group in Southern Wyoming, and which plainly belongs to the subgentts Brachyspira Pfeiffer. NERITID^E. Since the greater part of the known species of this family, both living and fossil, are of marine origin, only those of its fossil representatives which are found associated with such forms as indicate that they lived in a brackish or nearly fresh water habitat will be considered in this article. The species thus falling under consideration embrace two subordinate types of Neritina and these only. One of the types is apparently iden- tical with that of the common fluvatile living species of Neritina, which may be regarded as the typical section of the genus,t but the other type is extinct. Instead of having been confined to either brackish or fresh water, both these types have representatives in strata of both brackish water and marine origin. That is, for example, a species of each type is found in the Larainie group, associated with Corbicula, Corbula, Unio, and Melania. Other species of both types are found in Cretaceous strata, associated with such unmistakably marine forms as the Aviculi- dae, Arcidae, Turritellidse, &c. The earliest species referable to this family which is at present known, and which comes within the scope of this article, is Neritina nebrascensis, Meek & Hayden,| which was found in the vicinity of the Black Hills, in strata believed by those authors to be of Jurassic age. It is plainly a true Neritina, but those authors found it associated with species that are regarded as indicating a purely freshwater habitat, namely, Unioy Vimparus, Lioplacodes, &c. It is represented on Plate 3. *An. Rep. U. S. Geol. Sur. Terr., for 1878, Part I, p. 45, pi. 19, fig. 4. t The Laramie species, N. wlvilineata, shows a faint crenulation of the border of the inner lip; and some small examples, apparently the young of this species, lately dis- covered, show a distinct denticulation of that border. Perhaps this species ought to bo referred to Nerita, but for the present I leave it with Neritina. t Paleontology of the Upper Missouri, p. 109. 458 NON-MARINE FOSSIL MOLLUSCA. The next species that are to be mentioned in the order of geological time are two that were discovered by Mr. Meek in the estuary deposit at Coalville, Utah, which has already been several times mentioned. One of these species was described by him under the name of Neritina bannisterij* and is represented on Plate 5. It is closely allied with the foregoing Jurassic species, and specimens of both have been found which still show the original color-markings of the surface. Neritina bannisteri has also a near ally in N. incompta White, from the marine Cre- taceous strata of the same epoch, and which is found in the same region. Indeed, it is not improbable that these two forms are only varieties of one and the same species. If so, the fact implies that the species ranged from marine into brackish waters, with no more than a varietal change as a consequence. Associated with this typical Neritina in the Cretaceous estuary de- posit at Coalville is a species which Mr. Meek described under the name of N. bellatula; and with it, also, another form, which he named N. carditoidesA The type specimen of the latter is very imperfect 5 but, judging from the characters which it shows, it is thought to be identical with N. bellatula. Both the forms are represented on Plate 5. These two last-named forms of Neritina belong to a subordinate type to which Mr. Meek gave the subgeneric name of Velatella. The type is an extinct one, as has already been intimated, and is at present known only in Cretaceous and Laramie strata.J In the Bear Eiver Laramie beds a very small species occurs, which I have described under the name of Neritina naticiformis.% It apparently belongs to the typical section of the genus. It is represented on Plate 7. The Laramie species belonging to the subgenus Velatella, which has been referred to, was first discovered at Black Buttes Station, in South- ern Wyoming, and described by me under the name of N. ( V.) baptista. \\ Numerous specimens of it have since been discovered in the Laramie strata east of the Rocky Mountains in Colorado, all of which, including the type specimens, have preserved upon their surface the original color markings with which they were ornamented while living, and which are represented by Figs. 16-20 on Plate 23. Associated with N. ( V.} baptista, at the Wyoming locality, is the form which I have described under the name of Neritina volvilincata^ and which is illustrated on Plate 23. The type specimens were found in Southern Wyoming and Northwestern Colorado, none of which showed *An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, p. 25, pi. 12, fig. 10. tFor descriptions and figures of these two forms, see An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, pp. 27, 28, pi. 12, figs. 7 and 8. t For a diagnosis of this subgenus, see An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, p. 27. $An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, p. 89, pi. 30, fig. 3. || An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, p. 89, pi. 29, fig. 6. 11 An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, p. 88, pi. 21, fig. 6. WHITE.] ANNOTATED CATALOGUE. 459 the color markings such as are seen to characterize several species already noticed, and also the form referred to in the following paragraph. Associated with. N". (V.) Baptista in Northern Colorado, east of the Eocky Mountains, is a form of Neritina which is closely related to N.- volvilineata,) which being undescribed I propose for it the name N. bruneri in honor of Mr. Lawrence Bruner, who first discovered the species. It differs from N. volvilineata in being somewhat more globose, having a less elevated spire, and the inner lips broader and less re- treating. It is marked by revolving lines, somewhat like that species, but they are sometimes obsolete. It is also ornamented by zigzag color- markings. The type specimen is represented by Figs. 14 and 15 on Plate 23. Associated with the foregoing is still another form, much smaller, which seems to be the young of N. volvilineata. It is without color markings, and the inner border of the inner lip is dentate. Although belonging to so early an epoch, these Laramie species of Neritina are the latest members of that family of non-marine origin that are now known to occur in North American strata. Consequently, no others besides those mentioned come within the scope of this article. The typical form of Neritina has doubtless come down to the present daybysecuring a congenial habitat along the changing coasts of the grow- ing continent; but although the subgeneric type Velatella existed before the inclosure of the Laramie sea, that sea seems to have embraced all the forms of that type which survived during the Laramie period . When , therefore, the waters of that sea became wholly fresh, that type, together with others, seems to have been extinguished as a consequence. CERITHIID^E. Only a single species, referable to this family, which may be regarded as a non- marine form, has been found in any North American strata. It was obtained from the Judith Eiver Laramie beds, in the Upper Mis- souri Eiver region by Meek and Hay den, and by them described under the name of Gerithidea nebrascensis.* Those authors referred it to the subgenus Pirenella Gray, but they expressed some doubt as to the true generic character possessed by the shell. Although Gerithidea is a well known living genus of the Old World, this species at present Stands alone, or without near known allies, either living or fossil, among North American mollusca, if its generic relations are correctly under- stood, as stated above. It is represented on Plate 26. Most naturalists agree in the opinion that no living North American species of mollusca are properly referable to the genus Melania; although formerly many species were referred to that genus which are now placed in the family CeriphasiidaB, and mostly referred to the * U. S. Gcol. Sur. Terr., vol. ix, p. 559, pi. 43, fig. 9. 460 NON-MARINE FOSSIL MOLLUSCA. genus Goniobasis. It has also been considered doubtful by many natu- ralists whether any one of the fossil species that have been found in the rocks of North America, ought to be referred to the family MclaniidoB. The five or six following species, however, are in this article provsionally referred to that family ; two because they are at present believed to strictly belong there; and the others partly because of their apparent affinities in that direction, and partly because they seem to be not properly referable to the Ceriphasiidre. They are all interesting shells, embracing three distinct types, two of which, at least, are not known to have living representatives; but two of the species, while they appear to have no generic representative living in North America, seem to be referable to true Melania of Old World type. One of the species last referred to is Melania wyomingensis Meek, (—M. larunda White,*) which has been found on both sides of the Itocky Mountains in Southern Wyoming and Northern Colorado. Figures of this fine species are given on Plate 26. The other species, which appears to be a true Melania, is M. claiborn- ensis Heilprin, from the marine Eocene deposits of Alabama.t It is represented on Plate 28. In Southern Wyoming Mr. Meek also obtained from the Laramie strata a form which he described under the name of Melania insculpta.$ It seems to be nearly related to M. wyomingensis^ but differs from it in wanting its prominent subspinous ornamentation. This species has also been found in the Laramie strata east of the Eocky Mountains in Colorado, the specimens figured on Plate 26 having been collected in the valley of South Platte Eiver. There occurs somewhat abundantly in the Bear Eiver Laramie beds of Southwestern Wyoming and the adjacent parts of Utah a shell which Mr. Meek first referred to Melania^ but to which he afterward gave the new generic name of Pyrgulifera, describing it under the name of Pyrgulifera humrosa.§ It is illustrated on Plate 6. Mr. Meek placed this shell among the CeriphasiidaB or American Melanians, but as it seems to differ quite as widely from the typical forms of that family as it does from the true Melanians, I here place it provisionally * An. Rep. U. S. Geol. Sur. Terr, for 1878, Part I, p. 95, pi. 28, fig. 6. t Although the associates of this shell are all marine, it is given a place in this article hecause Melania is generally regarded as a fresh-water genus. In this connec- tion, however, it is proper to remark that among certain fossil faunae shells undis- tinguishable from Melania are found associated with marine forms. (See Professor Heilprin's description and remarks, Proc. Acad. Nat. Sci., Phila., 1879, p. 214.) M. wyomingensis and M. insculpta have also been found in such association with Ostrea and Anomia, as to indicate that they all lived and flourished together in the same waters, which were certainly in some degree saline, or the Ostrea and Anomia could not have existed there. * See An. Rep. U. 8. Geol. Sur. Terr, for 1878, Part I, p. 94, pi. 20, fig. 4. $ For diagnosis of this genus, and description and figures of the species, see U. S. Geol. Sur. 40th Parallel, vol. iv, p. 146, pi. 17, fig. 19. wmm] ANNOTATED CATALOGUE. 461 with the latter family. It is the only known species of the genus which has been proposed to receive it, either fossil or living.* From the fresh-water Miocene deposits, which have already been men- tioned as occurring in Sou them Idaho and in the vicinity of the Kawsoh Mountains, Mr. Meek described two forms and Mr. Gabb another, which they referred to Melania, Mr. Meek doing so with an expression of doubt but Mr. Gabb with none. Copies of their origin al figures of these^forms are given on Plate 32. Mr. Meek gave the names M. ? sculptilis and M. ¥ subsculptilis] to his two species, and Mr. Gabb, that of M. taylorilf. to the one he described. Conrad's M. decursa is probably a synonym of the latter. All three of these forms belong to one and the same type, and per- haps represent only one species. This type differs considerably from the other types that have herein been referred to the Melaniada3. The species belong to a fauna from which, as before stated, no genetic lines seem to have reached the present Mississippi drainage system, and, like a portion of their associates, are quite unlike any other North American species, either living or fossil. All the known species of that fauna are herein referred to and figured, but, for the purpose of separate view, their names are given, as follows : Melania f sculptilis, M. f subsculp- tilis , M. f taylorij Lithasia antiqua, Garinifex, ( Vorticifex) tryonij C. (V.) binneyi, Ancylus undulalus, Sph 4 fl 0 Laramie. Tertiary. Post- tertiary. i Miocene. 1 | s C? £ CONCHIFERA. OSTREID.E. x ANOMIUXE. MYTILID^;. Volsella (Brachydontes) regularis "W x V. (B.) laticostata W UNIONID^E. Anodonta?cat8kiUensi8(Vanuxem) Hall. x A. ? angustata ( Vaimxem) Hall x A.parallela W N.lsevia D Unio cristonensis M ........... X? Unio gaUinensit M. .......... . Xf x? U.nncalia M. & H TT. steward! W U. (Margaritana f ) hubbardi Gabb U. penultimus 0- TL belliplicatua M U. subspatulatua M. & H x U. danao M. & H x U. cryptorhynchusW x U.sencctus W U.couesii W x U.endlichi W 472 WHITE.] TABLE OF NON-MARINE FOSSILS. 473 Tabular view of the non-marine fossil mollusca of North America — Continued. • 1 Carboniferous. ! Jurassic. Cretaceous. | Tertiary. Po8t- tertiary. | 1 TJ- -§ i CONCHIFERA— Continued. UNIONID^: — Continued. x TT proavitus TV X X x TJ aldrichi W x x U. mendax "W x x x V CYRENID.E. C. occidentals 'M.&.H x C. (L.) subelliptica M. & H . • x x x S ? idahoense M PISIDIHXE. x CORBULIDJE. x C. undifera M x X 474 NON-MARINE FOSSIL MOLLUSCA. Tabular view of the non-marine fossil mollusca of North America — Continued. 1 1 Triassic. Jurassic. Cretaceous. Laramie. Tertiary. Post- tertiary. Eocene. Miocene. 1 Quaternary. *i CONCHIFERA— Continued. CORBULID^E— Continued. Corbula subtrigonalis Meek & Hayden . . . X O CTdssoteUifonnis Meek x GASTEROPODA. AURlCULHXiE. x x UMN2EID.E. x x x V L similis M V V L (Polyrhytis) kingii M v? x P. convolutuaM . & H x P. (Bathyomphalus) amplexusM. & H x x P. spectabilis M V V P.leidyi M.&H v? Carinifex (Vorticifex) tryoni M V C. (V.) binneyi M V PHYSHXE. P.copei W : P.feUxW P.pleromatis "W V P.secalina E. & S B. subelongatus M. & H. . . X WIIITE.J TABLE OF NON-MARINE FOSSILS. 475 Tabular view of the non-marine fossil mollusca of North America — Continued. Devonian. Carboniferous. Triassic. Jurassic. Cretaceous. Larimie. Tertiary. Post- tertiary I flj 1 6 4 Quaternary. | Eecent. GASTEROPODA— Continued. PHY SID^E — C ontinued. x x x x ANCYLIDJS. x V Latia dallii "W x AKIONID^E. x v? VITRINID.E. Vitrina ? obliqua M & H x x H. ? evansi M & H x x HELICLD,E. x Helix vetusta M & H x H. (Strobila?) kanabensis W x H. (Patula ?) sepulta W x H. (Triodopsis?) evanstonensis "W x H. ( Aglaia ?) peripheria "W x H. ( Arianta ?) riparia "W x H. (A. ?) leidyi Hall & Meek V H. ? veterna M. & H V Thaumastus limna^formis M. & H x V Columna teres M. & H x PUPIDuE. Pupa vetusta D x P.bigsbyi D x P. vennillionensis Bradley x Anthracopupa ohioensis Whitfield x Pupa (Leucocheila ?) incolata "W x P. (Pupilla?) arenula W x P. (P.?) atavuncula "W" x SUCCINID^E. Succinea (Brachyspira) papillispira W . . . NERITID^E. "Nuritin.i nnhm^npTlSig 1VT fa H x i N. naticifonnis W... X 476 NON-MARINE FOSSIL MOLLUSCA. Tabular view of the non-marine fossil mollusca of North America — Continued. Devonian. Carboniferous. o H o 1 Cretaceous. | Tertiary. Post- tertiary. Eocene. Miocene. 1 s Quaternary. Eecent. GASTEROPODA— Continued. NERITIDJS — Continued. x x N bannister! Meek X N (Velatella) bellatula M x N ( V ) carditoides M x N (V ) baptista "W ... x CERITHIID.E. Ceritbidea nebrascensis Meek & Haydcn. MELANIIIXE. x x V JLf larunda "W x M. ?insculpta M x M. ? sculptilis M • V Jf 1 subsculptUis M x Pyrgulifera humerosa M x x CERIPHASIID^J. Gouiobasis cleburni W X G chrysallis M X G. chrysalloidea "W G. macilenta "W X G. (Lioplax ?) endlichi W . X G. convexa M. & H X G. in venusta M. & H X G.sublams M. & H x G.omitta M. & H G. ? subtortuosa M. & H x G. gracilenta M x G. (Lioplax ?) nebrascensis M & H X G. (Lioplax?) tenuicarinata M. & H x G. tenera Hall x G.nodulifera M L Lithasia antiqua Gabb Cassiopella tarricula W X RISSOID^:. Hydrobia sabconica M H.anthonyi M. & H H.eulimoides M H. warren ana M. & H H.recWW X II. utahensis W , WHITE.] TABLE OF NON-MARINE FOSSILS. 477 Tabular view of the non-marine fossil mollusca of Norlh America— Continued. I Carboniferous. Triassic. Jurassic. Cretaceous. Laramie. Tertiary. Post- bertiary. 1 | Miocene. 03 5 Quaternary. 1 GASTEROPODA— Continued. RISSOID^E — Continued. Micropyrgua minutulas Meek&Hayden. x x VIVIPARID.E. Viviparus gillianus M & H x Iiioplacodes veternus M & H .... . 1 . . x Viviparus couesii White . ............ X X x V conradi M &H V.peculiaris M. & H V trochiformis M & H X X x V Jeidyi M & H V.leai M.&H x V. reynoldsiauus M. & H x V. retusus M. & H x V.prudentius W x V. plicapressus "W x V. pan^uitchensis W x V. ionicus \V . X? V. paludinaeformis Hall x V. wyomingensis M x Tulotoma thorapsoni W x x C. vetula M. &H x 0. multistriata M. &H x C. multilineata M. & H x X VALVATTD.E. Valvata scabrida M. & H X V. montanaensis M x V. suburabilicata M. &H x V.parvula M.&H x SPURIOUS AND DOUBTFUL SPECIES. The species mentioned in the following notes were not included in the foregoing list because a part of them do not belong to the uon -marine mollusca as they were supposed to do by the authors who first described them 5 concerning the true character of others there is some room for doubt, and the published information concerning the remainder is either unsatisfactory or erroneous. In the Annual Report of the Geological Survey of New York for 1830, pp. 65, G6, Mr. T. A. Conrad published descriptions of four species of mollusks from the Medina Sandstone (Upper Silurian) under the names respectively, of Planorbis trilobatus, Cyclostoma pervetuHta^ Unio primi- genius, and U. orthonotus. All these are now known to be marine spe- cies, and to belong, respectively, to the genera Bucania, Pleurotomaria, Cyprieardites, f and Modiolopsis. In the American Journal of Science and Arts (1.), Yol. XXIX, p. 149 et scq, Plate 1, Figs. 17-22, Dr. S. G. Morton briefly described and rudely figured five forms which he named, respectively, Unio petrosus, U. tumu- latus, U. terrenus, U. saxulum, and Anodonta hildrethi; and which he reported as having been obtained from Coal-measure strata in southern Ohio. If these fossils were really obtained from Coal-measure strata, our present knowledge of the fauna of that period, at least as it was developed in the region indicated, makes it improbable that they were correctly referred to the genera Unio and Anodonta. It is more prob- able that they were obtained from a post Tertiary deposit, and that they really belong to living species. In the proceedings of the Academy of Natural Sciences of Philadel- phia, 1868, pp. 162-164, Dr. Isaac Lea described ten species under the following names, respectively : Unio nasutoides, U. radiatoides, U. subro- tundoides, U. cariosoides, U. humerosoides, U* roanokoides, U. ligament- oides, U. alatoidcs, Anodonta grandioides, and A. corpulentoides. They were obtained from a deposit in New Jersey which Dr. Lea regarded as "Lower Cretaceous," but which is almost certainly of post Tertiary date. Moreover, they probably belong to the living species, the resem- blance to which is so plainly indicated by the respective names which Dr. Lea applied to them. In Paleontology of California, Vol. II, p. 88, Mr. Ga.bb speaks of having found the following species of Helix in a fossil condition, in different parts of that State, part of them being referred to strata of Pliocene age, although the species are all now living in that region : Jlclixfracta Newcomb, H. hildebrandi Newcomb, 77. mormonum Pfr., 77. tryoni Newcomb, and H. tudiculata Biniiey. Mr. H. C. Lea described a shell under the name of Turlo alaber in the 478 WHITE.] GENERAL DISCUSSION. 479 Transactions of the American Philosophical Society, Yol. IX, p. 267, Plate 37, Fig. 87, which Mr. Conrad stated in Proc. Acad. Nat. Sci. Philad. 18G2, p. 567, to be identical with the Paludina subglobosa. of Emmons (Geology of North Carolina, p. 273, Fig. 186). This assumed identity is doubtful. The latter is probably either a Viviparus or a Campeloma. The former is probably neither. From the Eocene strata of Wilmington, North Carolina, Sir Charles Lyell obtained the natural cast of a shell which he referred to Paludina and published (Jour. Geol. Soc. Lond., Yol. I, p. 431) a figure of it, but without a specific name. Conrad subsequently (Am. Jour. Conch., Yol. I, p. 32) gave the name Viviparus lyelli to this form. It is probably a true Viviparus, but its characters are not sufficiently known to settle the question definitely. In Fremont's Keport on Oregon and Northern California, pp.308, 300, Plate III, Professor Hall has figured and described several forms which have not been mentioned in the body of this article. They probably belong to a fresh-water fauna, although it was supposed that they were of marine origin when they were described. The specimens he had were evidently imperfect, but I have never seen them, and I have been una- ble by aid of Professor Hall's descriptions and figures to identify the species which they represent among any collections made in the West. The following are the names given them by Professor Hall in the work cited: Nucula impressa (?), Cytherea parvula, Plemotomaria uniangulata, Cerithium fremontij Natica(f) occidentalis, and Turritella bilineata. In Yol. Ill, p. 10, American Journal of Conchology, Mr. T. A. Con- rad published a description and figure of a shell from the Carbonifer. ous strata of Kansas, under the new generic name of Prisconaia, refer- ring it to the Unionidae. It is probably a species of Schizodus, and there- fore belongs to the Trigoniida3. In Yol. YI, of the same Journal, Conrad described Melania decursa and Anodonta decurtata u from Colorado." Because he did not state any locality or formation from which they were obtained, these species are not include in the text of this article. The former is probably from Oregon and identical with M. taylori Gabb. GENERAL DISCUSSION. Upon the preceding pages I have presented a synopsis of all the known fossil non-marine mollusca of North America, in the course of which it has been shown that many of the types now recognizable among the living non-marine mollusks have great antiquity ; but that certain of the types which have been recognized only among the fossil species, and are therefore regarded as certainly extinct, were contem- poraneous with many of those which survived. Before closing this 480 NON-MARINE FOSSIL MOLLUSCA. article it will be proper to present some general discussion of the nature of the relations which these fossil forms bear to each other and to those now living, and to make some suggestions as to the probable lines of descent of the latter, and the causes of the destruction of those which have failed to survive. In the present state of general knowledge of the subject, it seems hardly necessary to state in detail that these relations are regarded by naturalists as genetic in their character, and that the various forms which we discover, both living and fossil, have been evolved from pre- existing primary forms. If the theory of the evolution of organic things is to be accepted in any sense, it seems necessary to conclude that mol- luscan life began in the sea, and that all fresh- water and land mollusca have been primarily derived from those of marine origin.* While it is not my purpose to discuss this theory as such, it will be necessary, in the course of the remarks which are to follow, not only to refer to some of the phases which the subject presents when viewed in relation to the probable origin and distribution of the non-marine fossil mollusca, but it will also be necessary to adopt that theory at least as a working and explanatory hypothesis. Indeed, without an hypothesis of this kind, the structural relations which we find to exist between those fossil forms among themselves and between the fossil and living forms are meaningless and unimportant. With the acceptance of such a theory investigations like these become part of the elucidation of a grand his- tory which has fortunately been self registering and subject to errors only of interpretation arising mainly from imperfection of evidence. If, as has been premised, the first inolluscan life began in the sea, and the first non-marine mollusca were evolved from those which originated in marine waters, we may well inquire whether at least a part of those non marine forms which subsequently existed had not also a similar origin, and whether we may not consequently regard the great tide of * It is well known that in the case of some families of living mollusca, while cer- tain species will thrive in brackish waters, none of them will live in perfectly fresh waters. Living examples of this fact are common, and some have been observed among the Lararnie fauna. But too many facts are known concerning the ability of other mollusks to pass from saline to fresh waters, to leave room for reasonable doubt that the fresh-Water mollusca were primarily derived from the marine. Moreover, the evidence seems conclusive that many species whose living congeners are found exclus- ively in fresh waters were in former geological epochs able to live in waters that were more or less saline. It is the opinion of the writer also that in all or nearly all cases where marine types of mollusks, fishes, &c., have been found in brackish and fresh waters, or their remains in deposits of such origin, they have become habituated to such waters by having been landlocked by the rising sea-bottom around them. That is, they were probably forced to conform to a change of habitat that they would not have voluntarily chosen. It is probable also that, as a rule, the fresh water mollusca have been developed as such by compulsion of this character and not by voluntarily forsaking marine for fresh waters. Once developed as purely fresh water mollusca, certain forms at least became incapable of a return to marine waters; but certain other forms seemed capable of surviving a partial but not complete freshening of the waters. WHITE.] GENERAL DISCUSSION. 481 non-marine molluscan life that has come down to us from the past as having been made up of many contributing streams which had the sea as their source, rather than regard it, figuratively speaking, as a stream having an ancient and perhaps single source, augmenting in volume and throwing off from itself numerous branches which became collateral lines of descent. It is reasonable to suppose that both these conditions of evolution have prevailed, namely, that while some of the genetic lines of the non-marine mollusca may, and doubtless do, run back to paleozoic time, the families of non-marine mollusks have had many accessions from the sea from time to time during the successive geological ages, and that each of these accessions was, at least potentially, the source of subsequent collateral lines of descent. But the question of the primary origin of these lines of descent is not an essential one in these discus- sions, because I propose now only to consider the evidence that they have existed, and make some inquiry into the character and relations of certain of those lines which may be regarded as directly lineal. In these inquiries I shall treat coincidences of structure among the fossil and recent shells which come under consideration not only as indica- tions but as proof of genetic relationship ; and this relationship as funda- mentally pertaining to the geological and zoological history of the mol- luscan life which they represent. It is true that the incompleteness of the material which is or that we may ever hope to have available for study is so great as to leave many gaps, at least in the details, of the life-histories of all the types which have been recognized among the fossil mollusca. When, therefore, we come to trace the probable lines of succession of the various types of non-marine mollusks, we are met with certain difficulties, both apparent and real j and in endeavoring to account for the manner in which those lines may have been preserved unbroken through successive geological periods, the difficulty seems especially great, when casually considered, in the case of the fresh-water gill- bearing mollusca. The prevalence of the sea has always been practically universal j and the various movements which the earth's crust has undergone since life began in the sea, while they have repeatedly disturbed or destroyed the habitats of its molluscan denizens in certain localities, and have broken many of the lines of genetic succession of types that had from time to time become established, there has evidently never been anything like such a general destruction of life in the sea as would either break or materially interfere with the greater part of the principal lines of such succession. In short, the marine field for the development and perpe- tuity of molluscan life has been ample and unbroken from the beginning to the present time, and we are at no loss to understand how continuous lines of genetic succession of its denizens may have extended down through all the geological ages, modified, it is true, by immediately environing and cosmical causes, but still unbroken. We may at least 31 G 482 NON-MARINE FOSSIL MOLLUSCA. conclude that if every molluscan species that now exists in the sea has not been lineally derived from the earliest molluscan forms that have existed in it, there have been no such changes of its physical conditions as would preclude such a possibility. When we come to the study of the fossil pulmouate mollusca, especi- ally the laud-shells, we have also little or no difficulty in understanding how it has been possible for continuous lines of existence of these mollusks to be preserved through successive geological periods upon any continental area, such for example as North America, notwithstand- ing the numerous and great physical changes that have taken place within its area during those periods. Being air-breathers, nothing has apparently occurred to prevent their safe migration to other ground whenever that which they may have at any time occupied became" un- congenial by reason of physical changes, because, as a rule, those changes were effected so slowly that a continuity of congenial habitat for such mollusks was not necessarily broken. They were thus appar- ently as capable of preserving a continuous existence through succes- sive geological periods as the marine mollusca were. But, as before intimated, when we come to the study of the fossil shells of the fresh- water gill-bearing mollusca, which in their living state must necessarily have been confined to fluvatile and lacustrine waters, it is not easy to understand, without a special explanation, how continuous genetic lines could have been preserved (as we find they were preserved even down to the present time) through a succession of geolo- gical periods, during which the great lakes, as we know, and all the rivers, as is generally but erroneously believed, in which those mollusks lived, have been successively obliterated. * Elvers are separated from each other by intervening land, and, running to the sea, their mouths are separated by marine waters, neither of which barriers are fresh-water gill-bearing molluska capable of passing. But if it can be shown that throughout those geological periods and down to the present time there has been direct continuity of fresh water by means of lakes or rivers, or both, the case is plain enough. Indeed, as precarious as the exis- tence of continuous life of that kind may seem to have been, under the circumstances of such vast physical changes as are known to have oc- curred, we are forced to conclude that it is in this direction that we must seek for an explanation of the manner in which were preserved * It may be suggested that the distribution of these forms from one river or river system to another, may have taken place by the transportation of the mollusks or their eggs by aquatic birds. While such transportation is admitted to have been possible in some cases, it cannot be admitted as a probable cause of any considerable part of the distribution that must have occurred during the several geological epochs in which the molluscan types referred to are known to have existed. Notwithstand- ing the annual migration of myriads of aquatic birds between the northern and southern portions of North America at the present time, and doubtless also ever since It has been a continent, the fresh -water molluscan failure of those regions, respectively, are still distinct. WHITE.] GENERAL DISCUSSION. 483 the fresh-water molluscan types that have been found in the various groups of North American Mesozoic and Cenozoic strata, and that'we also find among living mollusca. That is, they have been preserved through a continuity of habitat in the congenial fresh waters of lakes and rivers, flourishing in the lakes, when they existed, as well as in the rivers, and escaping by the streams which were the former outlets and inlets of the lakes, but which continued to flow after the obliteration of the latter, as rivers or tributaries of river systems. Lakes are only parts of unfinished river systems which disappear by being drained when the system is finished by the gradual wearing down of its channel. A lake consequently contains essentially the same aqueous fauna that the fluvatile portion of the system does in case the water of the lake is wholly fresh ; or a modification of that fauna if the waters of the lake are more or less saline. The great lakes which existed in Western North America in the Tertiary and Laramie periods successively became obliterated, but we may reasonably conclude that at least a part of the river channels of to-day have existed as such from earlier geological times; that the greater part of them were established in epochs anterior to our own, and that those of some of the tributaries of the present Mississippi Kiver system are identical, at least in part, with former outlets or inlets, or both, of the great ancient lakes which have just been referred to. Consequently we may reasonably conclude also that the molluscan fauna of the Mississippi Eiver system is lineally descended from the faunae of those ancient lakes, and the river systems of which they constituted lacustrine portions.* This view is confirmed * I here include the Laramie Sea in the use of the term " lacustrine," the term "sea" being used simply to indicate that its waters* were saline and not fresh ; just as the Black and Caspian are called seas instead of lakes, and for the same reason. It may eeem to be the use of a misnomer to speak of the Laramie Sea as a part of a river sys- tem, because it was so immensely large, and the continental area which was drained into it was proportionally so small, but if these views concerning the conditions which then existed are correct, that sea, with its tributaries and outlet, differed only in de- gree and not in kind, from any river system which has a lake of any size in its prin- cipal course. The waters of that sea having been saline, the Laramie hydrographic system more nearly resembled that of the Black Sea than any other now existing that is equally well known ; and, although the ancient sea has long since disappeared from the face of the earth, its "Hellespont " still flows as a part of the Missouri River, or of some one of its tributaries. The commingling of brackish-water and fresh- water fossil forms in an estuary de- posit is readily explained by the supposition that the river which debouched into the estuary brought down the latter and mingled them with the former. But the com- mingling of brackish- water and fresh-water forms occurs in some portions of the Laramie deposits under such conditions as to compel the belief that some of them at least lived and thrived together. There is evidence also that the fresh-water fauna proper of the Laramie system not only inhabited the streams which emptied into its sea, but that in great and shifting areas of the sea itself the waters were sufficiently fresh to allow the existence in them of such mollusks as Unio, Goniobasis, Yiviparus, Campeloma, &c., and saline enough in other parts for the existence of Ostrea, Anomia, Corbula, &c. This view of the conditions of the Laramie Sea being accepted it is plainly seen to have been, what Ritter has aptly termed, an unfinished river system, though an extreme example. 484 NON-MARINE FOSSIL MOLLUSCA. by the identity of the living with the fossil molluscau types, which has already been referred to. Rivers have of course existed ever since a sufficient extent of conti- nental surface was raised above the sea to accumulate the waters that fell from the clouds ; and in view of the mighty changes that have taken place during the progressive growth of the North American continent, especially the elevation of its great mountain systems and plateaus, it would be natural to suppose that the earliest rivers at least have been obliterated. Some have no doubt been obliterated, but contrary to what has been the general belief, the recent labors of Powell, Button, and others have shown that the rivers of North America have been among the most persistent of its physical features ; that many of them are older than the mountain ranges of the regions which the rivers traverse, and that they have not yielded their " right of way" when the mountain ranges and plateaus were raised, but continued during and after that elevation to run in essentially the same lines which they had chosen when the region they traversed was a plain instead of a mount- ainous one. That 'ancient river systems have been in some, and per- haps many instances, to a greater or less extent divided, as a consequence of unequal continental elevation, or from other causes, is quite certain; and it was doubtless in part by this means that the dispersion of fresh- water mollusca into different river systems has been effected. That some formerly existing rivers with their lacustrine portions have been obliterated and their molluscan fauna3 destroyed is doubtless also true, but these facts do not necessarily affect the correctness of the view con- cerning the general persistent integrity of rivers and river systems which has been referred to.* The coalescence of separate minor drainage systems by the confluence of their lower portions into a common channel during the progressive elevation of the continent has also been an important means of the dis- persion of fluvatile mollusca. By such coalescence, what were once sep- erate rivers or minor drainage systems became parts of larger ones ; as, for example, the union of the separate peripheral members of the great Mississippi River system, which now forms a common drainage for the principal part of the continent. The Ohio and Upper Mississippi, the two most ancient portions of the present great system, were once separate rivers, emptying into a northern extension of the Great Gulf; and it is practically certain that neither of them received that portion of the mol- * The discovery of so f*w traces of fluvatile deposits as have been made among the strata of the earth is probably due to the persistent adherence of rivers to their an- cient channels. When land upon which rivers have formerly run has subsided beneath the level of the sea, the fluvatile deposits were doubtless destroyed by the encroach- ing marine waters. If the land continued to rise, as has been so generally the case in the gradual production of the North American continent, the earlier river deposits were swept away hi later times by their own waters, as their valleys were broadened and deepened. It is therefore, as a rule, only in the deposits of lacustrine portions of ancient river systems (hat their fauna; have been WHITE.] GENERAL DISCUSSION. 485 luscan fauna, which now so strongly characterizes them, until after the confluence with them of the western portions of the present great river system which brought that fauna from its ancient home in the western part of the continent.* Eivers having been thus persistent, and the manner in which conflu- ence of the waters of many of them has been effected being understood, it is no more remarkable that the types of fresh-water gill-bearing mol- lusca have come down to us from former geological periods practically unchanged, than it is that marine and land mollusca have reached us bearing the imprint of their really ancient, but what we have been ac- customed to call, modern types. . The manner in which the various types of molluscan life have proba- bly come down to the present time from former geological periods hav- ing been pointed out, we come next to inquire to what extent the views thus expressed are confirmed by a* comparison of the living with the fossil non-marine mollusca. As regards the fresh-water and land mol- lusca, it may be stated without hesitation that those views are fully confirmed by such a comparison. That is, we find between the fossil and living faunae such an extensive agreement of types as to compel the conclusion that the former represent the latter ancestrally. It is true our investigations have shown that some of the types of fresh- water gill-bearing mollusca which existed in Mesozoic and Cenozoic time are not represented among living forms, having become extinct; but every family, almost every if not every genus, and many of the sub- ordinate divisions of those genera that are known among living North American fresh-water mollusca, have been recognized among the species that constitute the different fauna?, the fossil remains of which have been collected from the Mesozoic and Cenozoic strata of Western North America, t These investigations also show the interesting fact that while considerable numbers of types among the mollusca referred to have been from time to time extinguished, the extinguishment hav- ing in some instances taken place as late as the Pliocene epoch, few or no new ones appear to have been introduced to replace any of them * These remarks are made with especial reference to the Unionidse ; but they are also applicable to other gill-bearing mollusca, and they will no doubt apply with equal torce to at least a part of the ichthyc fauna of that great river system. The progeni- tors of the ganoids now living in that river system were doubtless originally land- locked in the Laramie sea, continued through the fresh water Eocene lakes, and finally escaped to the present river system in the manner already suggested. tThe extinctions referred to seem to have been caused by a failure of the waters in which the lost types lived, to secure a continuous flow into any existing liver system, This is of course equivalent to supposing an exception to the rule already announced, that rivers have been persistent ; but such exceptions being well authenticated would only add strength to the argument in favor of the rule. The portion of the Laramio Group known as the Bear Eivcr beds, and the Miocene Truckee Group of Nevada, Idaho, and Oregon, both containing extinct types, maybe taken sis indicating a failure of the waters in which they were respectively deposited to secure persistent continuity during subsequent time. 486 NON-MARINE FOSSIL MOLLUSC A. since the closing epochs of Mesozoic time. Fresh- water mollusca ap pear to have been less subject than marine mollusca to those cosmical influences which, from age to age and from epoch to epoch of geological time, progressively impressed the marine mollusca with their wonderful diversity of form and structure. While so large a proportion of the types among the fossil fresh- water and land mollusca are clearly recognized among those now living, a large proportion, if not the greater part of the fossil brackish- water types which are presented in this article, are different from those of the corresponding fauna now living. This is doubtless due to the fact that the lines of succession of most of the brackish-water mollusca, the remains of which we have had opportunity for study, were denizens of the brackish-water Larainie Sea, and were cut off by the final freshen- ing of its waters, from which there was no escape to the coasts of the open sea, where they might have Had a congenial habitat, while their contemporaries of the land and fluvatile waters survived. This fact has been mentioned on previous pages in connection with the presenta- tion of the several types referred to. It is, however, a remarkable fact that at least five of the types that are recognized among the fauna of the Laramie Group, namely, Bathyomplialus^ Cerithidea, Pyrgulifera, Melanopsis, and true Melania, have'never been found among the living fauna of North America, but are represented by living species in the old world. But this and other questions pertaining to the Laramie invertebrate fauna will be discussed in a monograph of that fauna now in preparation. 488 NON-MARINE FOSSIL MOLLUSC A. PLATE 1. DEVONIAN. STROPHITES GRANDJEVA Dawson. (Page 455.; FIG. 1. Fragment, enlarged. The small outline to the left shows the natural size. After Dawson. ANODONTA? ANGUSTATA (Vanuxem) Hall. (Page 424.) FIG. 2. Right side view, natural size. FIG. 3. Dorsal view of same. After Vanuxenv ANODONTA? CATTSKILLENSIS (Vanuxem) Hall. (Page 424.) FIG. 4. Right side view, natural size. After Vanuxem. U. S. GEOLOGICAL SURVEY ANNUAL REPORT 1882 PL 1 DEVONIAN. 490 NON-MARINE FOSSIL MOLLUSC!. PLATE 2. CARBONIFEROUS. PUPA VETUSTA Dawson. (Page 456.) Fio. 1. Lateral view, enlarged. Fio. 2. Apertural view, enlarged. After Dawson. DAWSONELLA MEEKI Bradley. (Page 453.) FIG. 3. Apertural view, enlarged. FIG. 4. Outline of under view, enlarged. After Whitfield. ANTHRACOPUPA OHIOENSIS Whitfield. (Page 456.) FIG. 5. Lateral view, enlarged. FIG. 6. Lateral view, outline showing edge of outer lip. FIG. 7. Lateral view, outline showing aperture. FIG. 8. Outline view of aperture, more enlarged. After Whitfield. PUPA BIGSBYI D. (Page 456.) FIG. 9. Lateral view, enlarged. FIG. 10. Lateral view of a smaller example, enlarged. After Dawson. ZONITES PRISCUS D. (Page 453.) FIG. 11. Lateral view, enlarged. FIG. 12. View showing the aperture, enlarged. After Dawson. PUPA VERMILLIONENSIS B. (Page 456.) FIG. 13. Lateral view, enlarged. FIG. 14. Lateral view, showing the aperture, enlarged. After Dawson. NAIADITES CARBONARIA D. (Page 425.) FIG. 15. Left side view, natural size. After Dawson. NAIADITES ELONGATA D. (Page 425.) FIG. 16. Right side view, natural size, and enlarged. After Dawson. NAIADITES L.EVIS D. (Page 425.) FIG. 17. Left valve enlarged, and smaller examples of natural size. After Daweon. U. S. GEOLOGICAL SURVEY ANNUAL REPORT 1882 PI. 2 11. 12. 17. CARBONIFEROUS. 492 NON-MARINE FOSSIL MOLLUSCA. PLATE 3. JURASSIC AND TRIASSIC T UNIO STEWARDI White. (Page 426.) FIG. 1. Outline of a left valve restored from fragments, natural size. UNIO NUCALIS Meek & Hayden. (Page 426.) FIG. 2. Lateral view of a left valve slightly restored from a specimen a little crushed. FIG. 3. Dorsal view of the same ; the right valve restored in symmetry with the left. FIG. 4. Dorsal view of one of the originally figured types, slightly restored, the specimen being a little crushed ; all natural size. UNIO CRISTONENSIS Meek. (Page 425.) FIG. 5. Right side view of Mr. Meek's most perfect type, natural size. PLANORBIS VETERNUS M. & H. (Page 446.) FIG. 6. Lateral view, natural size, and the same enlarged; also, a transverse section showing the number and shape of volutions. After Meek. VALVATA SCABRIDA M. & H. (Page 470.) FIG. 7. Copy of original figure of Meek & Hayden. VIVIPARUS GILLIANUS M. & H. (Page 470.) FIG. 8. Two views of the type specimen, natural size. After Meek & Hayden. LIOPLACODES VETERNUS M. & H. (Page 470.) FIG. 9. Two views of the type specimen, natural size. After Meek & Hayden. NERITINA NEBRASCENSIS M. & H. (Page 457.) FIG. 10. Two views of the type specimen, natural size. After Meek & Hayden. FIG. 11. Enlarged view of a portion of the surface showing the pattern of the color markings. U. S. GEOLOGICAL SURVEY ANNUAL REPORT 1882 PI. 3 JURASSIC AND TRIASSICf 494 NON-MARINE FOSSIL MOLLUSCA. PLATE 4. CEETACEOUS. MARQARITANA NEBRASCENSIS Meek & Hayden. (Page 427. ) FIG. 1. Left side view, natural size. . FIG. 2. Dorsal view of the same. CYRENA DAKOTENSIS M. & H. (Page 436. ) FIG. 3. Left side view, natural size. FIG. 4. Dorsal view of the same. After Meek. PHYS A ? (Page 444 .) FIG. 5. Lateral view of an imperfect natural cast, natural size. U. 8, GEOLOGICAL SURVEY ANNUAL EEPOBT 1882 PI k CRETACEOUS. 496 NON-MARINE FOSSIL MOLLUSCA. PLATE 5. CRETACEOUS. UNIO PENULTIMUS Gabb. (Page 427.) FIG. 1. Copy of Mr. Gabb's original figure, natural size. UNIO HUBBARDI G. (Page 427.) <» FIG. 2. Left side view, natural size. FIG. 3. Outline of front view. After Gabb. CYRENA CARLETONI Meek. (Page 436.) FIG. 4. Left view, natural size. FIG. 5. Dorsal view of the same. ANOMIA pRorATORis White. (Page 422.) FIG. 6. Exterior view of an upper valve, natural size. FIG. 7. Lateral view of the same. NERITINA (VELATELLA) BELLATULA M. (Page 458.) FIG. 8. Dorsal view of a small example, enlarged. FIG. 9. Lateral view of another example, enlarged. NERITINA (VELATELLA) CARDITOIDES M. (Page 458.) FIG. 10. Dorsal view of the type specimen, natural size. NERITINA BANNISTERI M. (Page 458.) FIG. 11. Lateral view, enlarged, showing the color markings. The specimen has been a little compressed. FIG. 12. Two views of a small example, enlarged. The color markings are not pro- served in this example. MELAMPUS? ANTIQUUS M. (Page 444.) FIG. 13. Lateral view of a small example, enlarged. FIG. 14. Opposite view of the same. FIG. 15. Fragment of a very large example, natural size. FIG. 16. Apex very much enlarged, showing the reversed initial whorl. MELAMPUS ? — — ? (Page 444. ) FIG. 17. Lateral view, natural size. PIIYSA CARLETONI M. (Page 449.) FIG. 18. Lateral view, natural size. VALVATA NANA M. (Page 470.) FIG. 19. Lateral view, enlarged. FIG. 20. Summit view of the same. U. 8. GEOLOGICAL SURVEY ANNUAL REPORT 1882 PI. 5 CRETACEOUS. 32 G 498 NON-MARINE FOSSIL MOLLUSCA. PLATE 6. BEAR RIVER LARAMIE. UNIO BELLIPLICATUS Meek. (Page 430.) FIG. 1. Left side view, natural size. FIG. 2. Similar view of another example. FIG. 3, Dorsal view of a left valve, a little distorted, showing the plications of the umbo. PYRGULIFERA HUMEROSA M. (Page 460.) FIG. 4. Lateral view of a large example, natural size. FiG. 5. Opposite view of the same. This is the same example that is figured by Meek on p. 177 U. S. Geol. Sur. 40th Parallel, vol. iv, but it has since been cleaned of extraneous matter. FIG. 6. Lateral view of a smaller example. GONIOBASIS CLEBURNI White. (Page 462.) FIG. 7. Lateral view, natural size. . FIG. 8. Similar view of another example. FIG. 9. Fragment of a large example. GONIOBASIS CHRYSALLOIDEA W. (Page 462. ) FIG. 10. Lateral view, natural size. FIG. 11. Similar view of another example. GONIOBASIS MACILENTA W. (Page 462.) FIG. 12. Lateral view, enlarged. GONIOBASIS CHRYSALIS M. (Page 462.) FiG. 13. Lateral view, enlarged. FIG. 14. Similar view of another example. ^ LlMNJEA (LlMNOPHYSA) NITIDULA M. (Page 445.) FIG. 15. Lateral view, enlarged two diameters. FIG. 16. Opposite view of the same. PH YSA ? (Page 449. ) FIG, 17. Lateral view, natural size. LlMNJSA (ACELLA) HALDEMANI W. (Page 445.) FIG. 18. Lateral view, enlarged. FIG. 19. Opposite view of the same. U. 8. GEOLOGICAL SURVEY ANNUAL EEPOET 1882 PI. 6 10. 17. BEAR RIVER LARAMIE. 500 NON-MARINE FOSSIL MOLLUSC A. PLATE 7. BEAR RIVER LARAMIE. UNIO VETUSTUS Meek. (Page 430.) FIG. 1. Left side view of a large example; a little compressed laterally. FIG. 2. Right side view^ the posterior portion a little compressed vertically. FIG. 3. Dorsal view of Fig. 2 ; the left valve restored in symmetry with the right. FIG. 4. Interior view of a left valve. (All natural size.) NERITINA NATICIFORMIS White. (Page 458.) FIG. 5. Lateral view ; enlarged. FIG. 6. Opposite view of the same. GOXIOBASIS ENDLICHI W. (Page 463.) FIG. 7. Lateral view ; revolving lines faint. FIG. 8. Another example ; revolving lines obsolete. FIG. 9. Apical portion of another example ; revolving lines unusually distinct. (All natural size.) U. 8. GEOLOGICAL SURVEY ANNUAL REPORT 1882 PL 7 BEAR RIVER LARAMIE. 502 NON-MARINE FOSSIL MOLLU8CA. PLATE 8. BEAR RIVER LARAMIE. VIVIPARUS COUESII White. (Page 467.) FiO. 1. Lateral view of a very large example, natural size. RHYTOPHORUS PRISCUS Meek. (Page 444.) FIG. 2. Lateral view, natural size. FIG. 3. Opposite view of the same. After Meek. RHYTOPHORUS MEEKII W. (Page 444.) FIG. 4. Lateral view, natural size. FIG. 5. Opposite view of a larger example. CAMPKLOMA MACROSPIRA M. (Page 469.) FIG. 6. Lateral view, natural size. FIG. 7. Opposite view of the same. , CORBICULA (VELORITINA) DURKEEI M. (Page 437.) FIG. 8. Left valve. FIG. 9. Similar view of another example. FIG. 10. Dorsal view of another example. FIG. 11. Front view. (All natural size.) CORBULA PYRIFORMIS M. (Page 441.) FIG. 12. Right side view. FIG. 13. Dorsal view of the same. FIG. 14. Front view of the same. FIG. 15. Interior view of a right valve. FIG. 16. Interior view of a left valve. (All natural size.) U. S. GEOLOGICAL SURVEY ANNUAL REPORT 1882 PI. 8 U. 9. BEAR RIVER LARAMIE. 504 NON-MARINE FOSSIL MOLLUSCA. PLATE 9. LARAMIE. OSTREA GLABRA Meek & Haydeiu (Page 421.) FIG. 1. Exterior view of type; lower valve. After Meek. FIG. 2. Interior view of the same. FIG. 3. Exterior view of a lower valve, from the valley of the South Platte, Colorado. FIG. 4. Interior view of the same. (All natural size.) U. B. GEOLOGICAL SURVEY ANNUAL EEPOET 1S8S PI 9 LARAMIE. 506 NON-MAKINE FOSSIL MOLLUSCA. PLATE 10. LARAMIE. OSTREA GLABRA Meek & Hayden. (Page 421.) FIG. 1. Exterior view of an upper valve, from the valley of tlie South Platte, Colorado. FIG. 2. Interior view of the same. FIG. 3. Lower valve of the type of the variety 0. insecuris White; exterior view. FIG. 4. Interior view of the same. FIG. 5. Type specimen of variety O. arvuatilia Meek. (All natural size.) U. S. GEOLOGICAL SURVEY ANNUAL REPORT 1882 PL 10 LARAMIE. 508 NON-MARINE FOSSIL MOLLUSCA. PLATE 11. LARAMIE. OSTREA GLABRA Meek & Hayden. (Page 421.) FIG. 1. Exterior view of an upper valve of the variety 0. wyomingensis Meek, from the valley of the South Platte, Colorado. FIG. 2. Interior view of the same. FIG. 3. Exterior view of an example of the upper valve of the same variety, from Point of Rocks, Southern Wyoming. FIG. 4. Interior view of the same. (AH natural size.) U. S. GEOLOGICAL SURVEY ANNUAL REPORT 1882 PI. 11 LARAMIE. 510 NON-MARINE FOSSIL MOLLUSC A. PLATE 12. LARAMIE. OSTREA GLABRA Meek & Hay den. (Page 4:21.) FIG. 1. Interior view of an under valve of the variety 0. wyoming&nsis Meek ; from Point of Rocks, Southern Wyoming. Natural size. OSTREA SUBTRIGONALIS Evans & Shumard. (Page 421.) FIG. 2. "Exterior view of a lower valve. FIG. 3. Interior view of another example of the lower valve. FIG. 4. Exterior view of an upper valve. FIG. 5. Interior view of the same. (All natural size. ) ANOMIA MICRONEMA Meek. (Page 422.) FIG. 6. Exterior view of an upper valve, showing radiating lines of ordinary char- acter. FIG. 7. Similar view of another example, the lines upon which are very fine, and less conspicuous than they appear upon the figure. FIG. 8. Similar view of another example, having radiating lines much coarser than usual. FIG. 9. Interior view of a large, nearly flat, upper valve, showing the four muscular scars, and the process beneath the beak. FIG. 10. Similar view of another example, showing the process more plainly ; but the scars are obliterated. FIG. 11. Interior view, showing the under valve, with its byssal plug. (All natural size. ) ANOMIA GRYPHORHYNCHUS M. (Page 422. ) FIG. 12. Exterior view of a lower valve. FIG. 13. Similar view of two other valves. FIG. 14. Lateral view of Fig. 12. FIG. 15. Interior view of an upper valve, showing the muscular markings and the small process beneath the beak. (All natural size. ) U. S. GEOLOGICAL SURVEY ANNUAL REPOET 1883 PI. IS LARAMIE. 512 NON-MAKINE , FOSSIL MOLLUSCA. PLATE 13. LARAMIE. VOLSELLA (BRACHYDONTES) RKGULARIS White. (Page 423.) FIG. 1. Right valve, natural size. VOLSELLA (BRACHYDONTES) LATICOSTATA W. (Page 423.) FIG. 2. Right valve, natural size. UNIO PROAVITUS W. (Page 433.) FIG. 3. Left valve, exterior view. FIG. 4. Similar view of right valve. FIG. 5. Front view of another example. FIG. 6. Interior view of a left valve. (All natural size.) UNIO GOINONOTUS W. (Page 433.) FIG. 7. Right side view. FIG. 8. Front view of another example. FIG. 9. Left side view of young example. FIG. 10. Dorsal view of the same. (All natural size.) U. S. GEOLOGICAL SURVEY ANNUAL REPORT 1882 PL IS LARAMIE. 33 G 514 NON-MARINE FOSSIL MOLLUSCA. PLATE 14. LARAMIE. UNIO PRISCUS Meek & Hayden. (Page 432.) FIG. 1. Copy of the original figure of Meek & Hayden. Uxio SUBSPATULATUS Meek. (Page 431.) FIG. 2. Left side view. FIG. 3. Dorsal view of the same. After Meek. UNIO PRIM2EVUS White. (Page 432.) ^ FIG. 4. Exterior view of a small left valve. FIG. 5. Interior view of a large right valve. (Both natural size.) UNIO CRYPTORHYNCnus W. (Page 431.) FIG. 6. Exterior view of an imperfect right valve. FIG. 7. Interior view of a fragment of a left valve, showing the cavity behind the cardinal plate. V. S. GEOLOGICAL SURVEY ANNUAL REPOBT 1882 PL LARAMIE. 516 NON-MARINE FOSSIL MOLLUSC A. PLATE 15. LARAMIE. Uxio ENDLICIII White. (Page 432.) FIG. 1. Right valve of a large example, exterior view. FIG. 2. Interior view of a smaller left valve. (Both natural size.) UNIO PROPHETICUS W. (Page 433.) Fio. 3. Exterior view of a left valve. Natural size. UNIO ALDRICHI W. (Page 433.) FIG. 4. Left side view. FIG. 5. Dorsal view of the same. Natural size. U. S. GEOLOGICAL SURVEY ANNUAL REPORT 18W PI. 16 LAKAMIE. 518 NON-MARINE FOSSIL MOLLUSCA. PLATE 16. LARAM1E. Uxio COUESII White. (Pago 432.) FIG. 1. Exterior view of a left valve. Natural size. UNIO IIOLMBSIANUS \V. (Page 433.) FIG. 2. Left side view of an adult example. FIG. 3. Dorsal view of the same. FIG. 4. Left side view of a young example. FIG. 5. Front view of the same. FiG. C. Posterior view of the same. (All natural size.) UNIO BRACiiYOPiSTnus W. (Page 433.) FIG. 7. Right side view of an example not fully adult. FiG. 8. Front view of the same. Natural size. U. 8. GEOLOGICAL SURVEY ANNUAL REPORT 1882 PI. LARAMIE. 520 NON-MARINE FOSSIL MOLLUSC A. PLATE 17. L ARAM IE. Uxio DAN^E Meek & Ilaydcn. (Page 431.) FIG. 1. Left, side view. FIG. 2. Dorsal view of tlie same example. FIG. 3. Right side view of another example. After Meek. - Uxio DEWEYANUS M. & II. (Page 431.) FIG. 4. Left side view. FIG. 5. Interior view of the same. After Meek. CORBICULA OCCIDENTALS M. & II. (Page 437.) FIG. G. Left side view of the type of C. btinnisteri Meek. FIG. 7. Dorsal view of the same; natural size. (For other figures of C. occidental is, see Plate XXIII.) SriLEitiUM TLAXUM M. & IT. (Page 439.) FIG. 8. Exterior view of a left valve and outline of a dorsal view of the same; natural size. After Meek. SPUJERIUM RECTICARDINALE M. & H. (Page 439.) FIG. 9. Exterior view of a leffc valve and outline of a dorsal view of the same; natural size. After Meek. SPILERIUM SUBELLIPTICUM M. & II. (Page 439.) FIG. 10. Exterior view of the left valve, natural size, together with the same much enlarged. After Meek. SPII^RIUM FORMOSUM M. & II. (Page 439.) FIG. 11. Exterior view of the right side, natural size, together with side and dorsal views of the same much enlarged. After Meek. U. S. GEOLOGICAL SURVEY ANNUAL REPORT 1882 PI. 17 LARAMIE. 522 NON-MA"RINE FOSSIL PLATE 18. LARAMIE. UNIO DANJS Meek & Ilayden? (Page 433.) FiO. 1. Exterior view of the right valve of an example from Black Buttes Station, Southern Wyoming. FIG. 2. Interior view of a left valve from the same locality. (Both natural size.) UNIO MENDAX White. (Page 433.) FIG. 3. Exterior view of a left valve; adult. FIG. 4. Similar view of a smaller right valve. FIG. 5. Interior view of part of a right valve. (All from the Canon of Desolation, Utah; and^ill natural size.) CORBULA UNDIFERA Meek. (Page 440.) FIG. 6. Right side view of an adult example. FIG. 7. Dorsal view of the same. FIG. 8. Left side view of a smaller example. FIG. 9. Front view of the same. CORBULA UNDIFERA var. SUBUNDIFERA W. (Page 440. ) FIG. 10. Left side view of the type specimen. FIG. 11. Dorsal view of the same, natural size. CORBULA MACTRIFORMIS M. & H. (Page 440.) FIG. 12. Exterior view, left valve. FIG. 13. Interior view of the same. FIG. 14. Dorsal view of the same. FIG. 15. Interior view of the right valve of another example. (All natural size, and all after Meek.) U. S. GEOLOGICAL SURVEY ANNUAL REPORT 1882 PI. 18 LARAMIE. 524 NON-MARINE FOSSIL MOLLUSCA. PLATE 10. LARAMIE. Uxio SENECTUS White (Page 432.) Fio. 1. Exterior view of a portion of a right valve. FlO. 2. Interior view of a portion of a left valve. (Both natural size.) UNIO GONIAMBONATUS W. (Page 433.) FIG. 3. Left side view, natural size. FIG. 4. Dorsal view of the same. (Both figures are partial restorations, the type specimen having been dis- torted by compression.) , AXODOXTA PARALLELA W. (PagO 429.) FIG. 5. Left side view, restored from fragments ; natural size. ANODONTA PROPATORIS W. (Page 429.) FIG. 6. Left side view of an internal cast of large example. FIG. 7. Right side view of a similar cast of a larger example. FIG. 8. Dorsal view of the same. FIG. 9. Fragment showing the edentulous hinge. (All natural size.) COIIBULA SUBTRIGONALIS Meek & Hayden. (Page 442.) FIG. 10. Exterior view of a left valve, natural size. After Meek. FIG. 16. Exterior view of left valve of the variety C. perundata Meek. * FIG. 17. Similar view of another left valve of the same variety. (Both natural size, and both after Meek.) FIG. 15. Right side view of the variety C. tropidophora Meek, natural size. FIG. 14. Right side view of the variety C. crassatelliformis Meek, natural size. FIG. 11. Left side view of an example trom Crow Creek, Colorado; natural size. FIG. 12. Dorsal view of the same. FIG. 13. Left side view of another example from the same locality. U. S. GEOLOGICAL SURVEY ANNUAL REPORT 1882 PI 19 LARAMIE. 52 G NON-MARINE FOSSIL MOLLUSCA. PLATE 20. LARAMIE. CORBICULA (LEPTESTHES) FRACTA Meek. (Page 439.) FIG. 1. Copy of Mr. Meck's original figure. FIG. 2. Left side view of a robust example. FIG. 3. Dorsal view of tlio same. FlG. 4. Left side view of a young example. FIG. 5. Dorsal view of the same. FIG. 6. Left side view of a more elongate, partially cruslied example. (All natural size.) CORBICULA CLEBURXI White. (Page 437.) FIG. 7 Left side view of an adult example. FIG. 8. Right side view of a smaller example. FIG. 9. Interior view of the same. (All natural size.) CORBICULA SUBELLIPTICA Meek & llayden. (Page 437.) FIG. 10. Exterior view of a right valve; natural size. FIG. 11. Interior view of the same. CORBICULA NEBRASCEXSIS M. & H. (Page 437.) FIG. 12. Exterior of a left valve; natural size. FIG. 13. Interior view of the same. PISIDIUM SAGINATUM W. (Page 440.) FIG. 14. Lateral view, enlarged. FIG. 15. Front view of the same. U. S. GEOLOGICAL SURVEY ANNUAL REPORT 1882 PL 20 LARAMIE. 528 NON-MARINE FOSSIL MOLLUSCA. PLATE 21. LARAMIE. CORBICULA BERTnouDi White. (Page 438. ) FIG. 1. Left valve of a large example, exterior view. FIG. 2. Dorsal view of another example. FIG. 3. Interior view of a left valve. (All natural size ) CORBICULA AUGHEYI W. (Pago 433.) FIG. 4. Exterior view of a right valve. FIG. 5. Interior view of the same. FIG. 6. Dorsal view of another example. (All natural size.) CORBICULA UMBONELLA Meek. (Pago 438.) FIG. 7. Exterior view of a left valve. FIG. 8. Interior view of the same. FiG. 9. Dorsal view of another example. FIG. 10. Front view of the same. • CORBICULA (LEFTESTIIES) MACROPISTIIA W. (Pago 437.) FIG. 11. Left side view of an adult example. FIG. 12. Dorsal view of the same. FIG. 13. Left side view of another example. FIG. 14. Interior view of a left valve V. S. GEOLOGICAL SURVEY ANNUAL REPORT 1882 PI. LARAMIE. 34 530 NON-MARINE FOSSIL MOLLUSCA. PLATE 22. LARAMIE. • CORBICULA CYTHERIFORMIS Meek & Hayden. (Page 437.) FIG. 1. Left side view of a large example. FIG. 2. Right side view of a small example. (Both after Meek.) FIG. 3. Right side view of an example from Southern Wyoming. FIG. 4. Dorsal view of the same. FIG. 5. Hinge view of left valve ; from same locality. 'Fio. 6. Similar view of right valve ; from same locality. (All natural size.) CORBICULA (LEPTESTHES) PLANUMBONA Meek. (Page 437.) FIG. 7. Right side view of an adult example. FIG. 8. Dorsal view of the same. FIG. 9. Left side view of a large example. (All natural size.) CORBICULA (LEPTESTHES) CARDINI^FORMIS White. (Page 437.) FIG. 10. Left side view of a large example. FIG. 11. Dorsal view of the same. FIG. 12. Exterior view of a right valve of a smaller example. FIG. 13. Interior view of the same. FIG. 14. Dorsal view of another example. FIG. 15. Exterior view of a left valve, less transversely elongate than usual. (All natural size.) V. S. GEOLOGICAL SURVEY AXXf'AL REPORT 18S2 PI. LARAMIE. 532 NON-MARINE FOSSIL MOLLUSCA. PLATE 23. LARAMIE CORBICULA OCCLDENTALIS Meek & Hay den. (Page 437.) FiQ. 1. Exterior view of the right valve of an example from Yampa River. North- western Colorado. FIG. 2. Interior view of the same. FIG. 3. Dorsal view of the same ; the left valve restored in symmetry with the right FIG. 4. Left side view of an example from the same locality of less proportionate height than usual. FIG. 5. Dorsal view of the same. FIG. 6. Copy of one of Mr. Meet's original figures. (All natural size.) CORBICULA OBESA White. (Page 437.) FIG. 7. Exterior view, right side. FIG. 8. Dorsal view of the same. FIG. 9. Front view of the same. FIG. 10. Dorsal view of another example. FIG. 11. Interior view of a left valve. (All natural size.) NEKITINA VOLVILINEATA W. (Page 458.) FIG. 12. Lateral view, enlarged. FIG. 13. Opposite view of the same/ NERITTNA BRUNERI W. (Page 459.) FIG. 14. Lateral view, natural size ; showing color-markings. FIG. 15. Opposite view of the same. NERITTNA (VELATELLA) BAPTISTA W. (Page 458.) FIG. 16. Dorsal view of the type specimen from Wyoming, showing the cdior- mark- ings; enlarged. FIG. 17. Lateral view of the same. FIG. 18. Dorsal view of an example from Northeastern Colorado, showing the color- markings ; enlarged. FIG. 19. Lateral view of the same. FIG. 20. Inferior view of the same. MELANOPSIS AMERICANA W. (Page 461.) FIG. 21. Lateral view, enlarged. FIG. 22. Opposite view of the same, showing aperture and broken outer lip. FIG. 23. Similar view of the proximal portion of the same more enlarged, showing callus of inner lip and canal. LIMN.EA (PLEUROLIMN^A) TENUICOSTATA M. & H. (Page 445.) FIG. 24. Lateral view, natural size~and enlarged. After Meek. CASSIOPELLA TURRICULA W. (Page 464.) FIG. 25. Lateral view of the type specimen ; the proximal volutions a little broadened by compression. FIG. 26. Similar view of another example. FIG. 27. Similar view of a smaller example. FIG. 28. Lateral view of another example showing the umbilicus, and approximately the outline of the aperture. FIG. 29. Inferior view of a basal fragment of another example showing the umbilicus. U. S. GEOLOGICAL SURVEY 4 ANNUAL REPORT 1882 PI 28 LARAMIE. 534 NON-MARINE FOSSIL MQLLUSCA. PLATE 24. LARAMIE. VIVIPARUS RETUSUS Meek & Hay den. Page 467.) FIG. 1. Lateral view of an adult example. FIG. 2. Similar view of another example. FIG. 3. Lateral view of another example, showing aperture. (All natural size. ) VIVIPARUS CONRADI M. & H. (Page 467.) FIG. 4. Lateral view of an adult example. FIG. 5. Opposite view of the same. FIG. 6. Another example, more than usually elongate. VIVIPARUS LEIDYI M. & H. (Page 467. ) FIG. 7. Lateral view of the type specimen. After Meek. VIVIPARUS LEIDYI var. FORMOSUS M. & H. (Page 467.) FIG. 8. Lateral view of the type specimen. FIG. 9. Opposite view of the same. After Meek. VIVIPARUS TROCHIFORMIS M. & H. (Page 467.) FIGS. 10, 11,12, 13, 14, 15, and 16. Lateral views of different examples ; all natural size. TULOTOMA TIIOMPSONI White. (Page 467.) FIGS. 17, 18, 19, 20, and 21. Lateral views of different examples, showing the ornamen- tation of the first to be nearly like that of V. trochiformis, and the increas- ing size of the nodes towards the higher numbers; all of natural size, and all from Northern Colorado, cast of the Rocky Mountains. FIG. 22. Lateral view of an example from Southern Wyoming, west of the Rocky Mountains. VIVIPARUS PKCULIARIS M. & H. (Page 467.) FIG. 23. Lateral view of the type specimen of Meek & Hayden. FIG. 24. Opposite view of the same, natural size. VIVIPARUS PLICAPRESSUS W. (Pago 467.) FIG. 25. Lateral view, natural size. FIG. 26. Similar view of another example. ACROLOXUS MINUTUS M. & II. FIG. 27. Apical view, magnified to four diameters. U. B. GEOLOGICAL SURVEY ANNUAL REPORT 1882 PI, LARAMIE. 536 NON-MARINE FOSSIL MOLLUSCA. PLATE 25. LARAMIE. PHYSA COPEI White. (Pago 450.) FIG. 1. Lateral view, natural size. FIG. 2. Opposite view of the same. PIIYSA FELIX W. (Page 450.) FIG. 3. Lateral view of an imperfect example, natural size. BULINUS DISJUNCTUS W. (Page 451.) FIG. 4. Lateral view, natural size. FIG. 5. Opposite view of the same. BULINUS ATAVUS W. (Page 450.) FIG. 6. Lateral view, natural size. FIG. 7. Opposite view of the same. BULINUS LONGINSCULUS Meek & Hayden. (Page 451.) FIG. 8. Two lateral views of the same example, natural size. After Meek. BULINUS RHOMBOIDEUS M. & H. (Page 451.) FIG. 9. Lateral view, natural size. After Meek. BULINUS SUBELONGATUS M. & H. (Page 450.) FIG. 10. Lateral view, natural size. FIG. 11. Opposite view of the same. After Meek. HELIX KANABENSIS W. (Page 454.) FIG 12. Lateral view of an internal cast of the last volutions, showing the grooves left by the internal ridges near the aperture ; natural size. FIG. 13. Upper view of the same. FIG. 14. Under view of the same. COLUMNA TERES M. & H. (Page 454. ) FIG. 15. Lateral view, natural size, and enlarged. After Meek. COLUMNA VERMICULA M. & H. (Pago 454.) FIG. 16. Lateral view^ natural size, and enlarged. After Meek. VIVIPARUS PRUDENTIUS W. (Page 467.) FIG. 17. Lateral view, natural size. FIG. 18. Opposite view of the same. VIVIPARUS PANGUITCHENSIS W. (Page 467.) FIG. 19. Lateral view of an internal cast. FIG. 20. Opposite view of another example, showing a part of the surface markings. FIG. 21. Lateral view of another example, showing a portion of the natural surface of the shell. (All natural size.) VIVIPARUS REYNOLDSIANUS M. & H. (Page 407.) FIG. 22. Lateral view, natural size. FIG. 23. Opposite view of the same example. TlIAUMASTUS LIMNyEIFOKMIS M. & II. (Page 454.) FIG. 24. Apcrtural and opposite views of an example not quite aduU; natural size. U. 8. GEOLOGICAL SURVEY ANNUAL REPORT 1889 PI. 95 LARAMIE, 538 NON-MARINE FOSSIL MOLLUSCA. PLATE 20. LARAMIE. MELANIA WYOMINGENSIS Meek. (Page 460.) Fio. 1. Lateral view, showing the outline of the outer lip. FIG. 2. Similar view of another example. Fia. 3. Similar view of the distal volutions, showing those of the apical portion to be destitute of spines. MELANIA INSCULPTA M. (Page 460.) FIG. 4. Fragment of an adult example. FIG. 5. Fragment of a smaller example. (Both natural size, and both from Northeastern Colorado.) GONIOBASIS CONVEXA Meek & Hayden. (Page 463.) FIG. 6. Lateral view, natural size. FIG. 7. Opposite view of the same example. GONIOBASIS CONVEXA var. IMPRESSA M. & H. (Page 463.) FIG. 8. Lateral view, natural size. FIG. 9. Opposite view of the same example. GONIOBASIS? OMITTA M. & H. (Page 463.) J£iG. 10. Apertural and opposite views; natural size. After Meek. GONIOBASIS TENUICARINATA M. & H. (Page 463.) FIG. 11. Apertural and opposite views; natural size. GONIOBASIS GRACILENTA M. (Page 463.) FIG. 12. Apertual and opposite views of Mr. Meek's type specimen. FIG. 13. Lateral view of an example from Crow Creek, Colorado. (Both natural size.) LIMN^A ? COMPACTILIS M. (Page 445.) FIG. 14. Apertural and opposite views of Mr. Meek's type specimen, natural size. GONIOBASIS NEBRASCENSIS M. & H. (Page 463.) FIG. 15. Lateral view, natural size. FIG. 16. Opposite view of the same example. GONIOBASIS INVENUSTA M. & H. (Page 463.) Fia. 17. Lateral view of the type specimen of Meek & Haydeu, natural size. GONIOBASIS SUBL^EVIS M. & H.. (Page 463.) FIG. 18. Lateral view of the type specimen of Meek & Hayden, natural size. CERITHIDEA ? NEBRASCENSIS M. & H. (Page 463.) FIG. 19. Apertural and opposite views of the type specimen of Meek & Hayden, en- larged. After Meek. MlCROPYRGUS MINUTULUS M. & H. (Page 465.) FIG. 20. Apertural and opposite views of the type specimen of Meek & Hayden, enlarged. CAMPELOMA PRODUCTA White. (Page 469.) FIG. 21. Lateral view of an elongate example, regarded as the type. FIG. 22. Opposite view of the same. FIG. 23. Lateral view of a more robust example. FIG. 24. Opposite view of the same. FIG. 25. Lateral view of a subcarinate variety. FIG. 26. Similar view of another example of the same variety. FIG. 27. Similar view of another example of the same variety. * (All natural size.) U.S. GEOLOGICAL SURVEY ANNUAL REPORT 1882 PI. U. S. GEOLOGICAL SURVEY ANNUAL REPORT 1882 PI.S7 LARAMIE. NON-MARINE FOSSIL MOLLUSC A. 539 PLATE 27. LARAMIE. CAMPELOMA MULTILINEATA Meek & Hayden. (Page 469.) FIG. 1. Copy of Meek's original figure. FIG. 2. Lateral view of a larger example, showing a slight angularity at the distal side of the larger volutions. FIG. 3. Opposite view of the same. FIG. 4. Lateral view of another example, having the angularity a little more distinct. FIG. 5. Lateral view of another example, having the angularity distinct and promi- nent. FIG. 6. Fragment showing the aperture, and prominent angularity. FIG. 7. Lateral view of an example from Crow Creek, Colorado. Figs. 2-6 are from the valley of the Yellowstone, Montana. (All natural size. ) CAMPELOMA VETULA M. & H. (Page 469.) FIG. 8. Lateral view of the type specimen of Meek & Hayden. FIG. 9. Opposite view of the same, natural size. VIVIPARUS LEAI M. & H. (Page 467.) FIG. 10. Lateral view of a large example. FIG. 11. Opposite view of the same. FIG. 12. Lateral view of another example. FIG. 13. Opposite view of the same. FIG. 14. Lateral view of another example, a little more elongated than usual. (All'natural size.) CAMPELOMA MULTISTRIATA M. & H. (Page 469.) FIG. 15. Copy of Meek's original figure. PLANORBIS CONVOLUTUS M. & H. (Page 447.) FIG. 16. Upper, under, and peripheral views of the type specimen of Meek & Hay- den. After Meek. PLANORBIS (BATHYOMPHALUS) PLANOCONVEXUS M. & II. (Page 447.) FIG. 17. Upper view of the type specimen of Meek & Hayden, natural size. FIG. 18. Peripheral view of the same. After Meek. PLANORBIS (BATHYOMPHALUS) AMPLEXUS M. & H. (Page 447.) FIG. 19. Upper view of the type specimen of Meek & Hayden, natural size. FIG. 20. Under view of the same, enlarged. After Meek. PLANORBIS (BATHYOMPHALUS) KANABENSIS White. (Page 447.) FIG. 21. Upper view, natural size. FIG. 22. Under view of the same example. FIG. 23. Peripheral view of the same example. VALVATA? MONTANAENSIS Meek. (Page 470.) FIG. 24. Outline views, enlarged. After Meek. VALVATA SUBUMBILICATA M. & H. (Page 470.) FIG. 25. Upper and under views of the type-specimen of Meek & Haydeu, natural size. After Meek. 540 NON-MARINE FOSSIL MOLLUSCA. HYALINA? EVANSI Meek & Hayden. (Page 452.) FIG. 26. Outline views, enlarged. After Meek. HYALINA? OCCIDENTALS M. & H. (Page 452.) FIG. 27. Upper, under, and peripheral views of the type-specimen of Meek & Hay- den. After Meek. HELIX! VETUSTA M. & H. (Page 454.) FIG. 28. Apertural and opposite views of the type-specimen of Meek & Hayden; natural size. After Meek. HELIX EVAN8TONEN8IS White. (Page 454.) FIG. 29. Lateral view, enlarged. FIG. 30. Opposite view of the same example. FIG. 31. Under view of the same example. VITRINA OBLIQUA M. & H. (Page 452.) FIG. 32. Lateral view of type specimen of Meek & Hayden, natural size. FIG. 33. Apical view of the same. After Meek. GONIOBASIS? SUBTORTUOSA M. & H. (Page 463.) PIG. 34. Apertural and opposite views of the type specimen of Meek & Hayden, natural size. After Meek. HYDROBIA UTAHENSIS W. (Page 466.) FIG. 35. Lateral view, enlarged. HYDROBIA SUBCONICA Meek. (Page 465.) FIG. 36. Outline lateral view, enlarged ; copy of Meek's original figure. HYDROBIA? EULIMOIDES M. (Page 465.) FIG. 37. Outline lateral view, enlarged; copy of Meek's original figure. HYDROBIA RECTA W. (Page 466.) FIG. 38. Lateral views of two fragments, enlarged. HYDROBIA ANTHONYI M. & H. (Page 465.) FIG. 39. Lateral view, natural size and enlarged. After Meek. HYDROBIA WARRENANA M. & H. (Page 465.) FIG. 40. Lateral view, natural size and enlarged. After Meek. 542 NON-MARINE FOSSIL MOLLUSCA. PLATE 28. EOCENE. UNIO CLINOPISTHUS White. (Page 434.) FIG. 1. Left side view, natural size. FIG. 2. Dorsal view of the same. UNIO SHOSHONENSIS W. (Page 435.) FIG. 3. Left side view, natural size. UNIO HAYDEXI Meek. (Page 435.) FIG. 4. Right side view, natural size. FlG. 5. Left side view of a smaller example* UNIO WASHAKI.ENSIS M. (Page 435.) FIG. 6. Left side view, natural size. FIG. 7. Right side view of a sandstone cast. FIG. 8. Interior view of a fragment of a right valve. UNIO TELLINOIDES Hall. (Page 435.) FIG. 9. Copy of Hall's original figure. PLANORBIS (GYBAULUS) MILITARIS W. (Page 447.) FIG. 10. Upper view, enlarged. FIG. .11. Under view of the same example. BYTHINELLA GREGARIA M. (Page 466.) FIG. 12. Lateral view, enlarged. FIG. 13. Opposite view of the same. BULIMUS FLORIDANUS Conrad. (Page 454.) FIG. 14. Copy of Conrad's original figure. MELANIA CLAIBORNENSIS Heilprin. (Page 460.) FIG. 15. Lateral view, much enlarged, together with an outline of natural size. After Heilprin. U. 8. GEOLOGICAL SURVEY ANNUAL REPORT 1882 PL EOCENE. 544 NON-MARINE FOSSIL MOLLUSC A. PLATE 29. EOCENE. PLANORBIS UTAKENSIS Meek. (Page 447.) FIG. 1. Upper view, natural size. FIG. 2. Under view of the same example. FIG. 3. Peripheral view of the same. After Meek. PLANORBIS UTAHENSIS var. SPECTAEILIS M. (Page 447.) FIG. 4. Upper view, natural size. FIG. 5. Under view of the same example. FIG. 6. Peripheral outline of the same. After Meek. PLANORBIS CIRRATUS White. (Page 448.) FIG. 7. Upper, under, and peripheral views, enlarged. PLANORBIS .EQUALIS W. (Page 448.) FIGS. 8 and 9. Under and peripheral views, enlarged. FIG. 10. Upper view of a smaller example, enlarged. (All are imperfect, and perfect adult examples are doubtless larger.) HELIX PERIPHERIA W. (Page 455.) FIG. 11. Lateral view, natural size. FIG. 12. Opposite view of the same. HELIX RIPARIA W. (Page 455.) FIG. 13. Lateral view, natural size. FIG. 14. Opposite view of the same example. PUPA INCOLATA W. (Page 456.) FIG. 15. Lateral view, enlarged. FIG. 1(3. Opposite view of the same example, showing the aperture. FIG. 17. View of the same, showing the edge of the outer lip. PUPA ATAVUNCULA W. (Page 456.) FIG. 18. Lateral view, enlarged. PUPA ARENULA W. (Page 50 456.) • FIG. 19. Two lateral views of the type specimen. The rim of the aperture has been broken off. LIMN^A SIMILIS M. (Page 445.) FIG. 20. Lateral view, enlarged. FIG. 21. Opposite view of the sa*me. After Meek. LIMN.EA VETUSTA M. (Page 445.) FIG. 22. Lateral view, natural size. FIG. 23. Opposite view of another example, a little enlarged. After Meek. LIMNJEA MINUSCULA W. (Page 446.) FIG. 24. Lateral view, enlarged. FIG. 25. Opposite view of the same example. SUCCINKA (BEACHYSPIRA) PAPILLISPIRA W. (Page 457.) FIG. 26. Three views of separate examples, natural size, from gutta-percha casts in natural molds. ANODONTA DECURTATA Conrad. (Page 479.) FIG. 27. Lateral view, natural size, from an example believed to have been Conrad's type specimen. FIG. 28. Dorsal view of the same. The true geological age of this species is not cer- tainly known, but it is believed to be Eocene. U. 8. GEOLOGICAL SURVEY ANNUAL REPORT 1882 PI. #9 EOCENE. 35 G 546 NON-MARINE FOSSIL MOLLUSCA PLATE 30. EOCENE. MACROCYCLIS SPATIOSA Meek & Haydon. (Pago 452.) FIG. 1. Upper view, natural size. FIG. 2. Lateral view of the same example. FIG. 3. Under view of the same, all natural size. After Meek. HELIX ? VETERXA M. & H. (Page 454.) FIGS. 4 and 5. Copies of Meck's outline figures. PHYSA PLEROMATIS White. (Page 450.) FIG. 0. Lateral view of type specimen. FIG. 7. Opposite view of a larger example, a little distorted, probably belonging to this species. FIG. 8. Fragment of a very large example, believed to belong to this species. (All natural size.) PHYSA BRIDGEREXSIS Meek. (Pago 450.) FIG. 9. Lateral view, natural size. FIG. 10. Opposite view of a more robust example. VIVIPARUS PALUDiN,EFORMis Hall. (Page 468.) FIG. 11. Lateral view, natural size. FIG. 12. Opposite view of the same. VIVIPARUS WYOMINGENSIS M. (Page 468.) FIG. 13. Lateral view, natural size. FIG. 14. Opposite view of the same. D. 8. GEOLOGICAL SURVEY A NNUA L REPOB T 1883 PL SO EOCENE. 548 NON-MARINE FOSSIL MOLLUSCA. PLATE 31. All the forms represented on this plate occur in the fresh- water Eocene deposits of Wyoming, Colorado, and Utah ; and all are believed to be genetically related. They have been described by different authors under six respective names, according to the variation of ornamentation and form. (See remarks on page 464.) Figs. 1, 2, and 3 may be regarded as representing the Goniobasis simpsoni of Meek ; Figs. 5, 10, 12, and others, G. tenera Hall; Figs. 14, 15, 20, and others, G. nodulifera Meek; Figs. 19, 25, 28, and others, G. carteri Conrad; and Figs. 29 and 30, G. columlnis White. Fig. 31 is a copy of Meek's figure of G. arcta, which he finally regarded as only a variety of his G. simpsoni. It, is however, very like a form which occurs in the Larainie beds of Bear River Valley in Southwestern Wyoming. V. 8. GEOLOGICAL SURVEY ANNUAL REPORT 1882 PI 31 25. 17. M. U.S. GEOLOGICAL SrHVKY ANNUAL REPORT 1882 PL 32 MIOCENE AND PLIOCENE? NON-MARINE FOSSIL MOLLUSCA. 549 PLATE 32. MIOCENE AND PLIOCENE? MELANIA SCULPTILIS Meek. (Page 461.) FIG. 1. Lateral view, natural size. After Meek. MELANIA SUBSCULPTILIS M. (Page 461.) FIG. 2. Lateral view, natural size. After Meek. MELANIA TAYLORI Gabb. (Page 461.) FIG. 3. Lateral view, natural size. After Gabb. LITHASIA ANTIQUA G. (Page 465.) FIG. 4. Lateral view, showing the aperture, natural size. After Gabb. CARINIFEX (VORTICIFEX) BINNEYI M. (Pago 448.) FIG. 5. Lateral view, natural size, showing the aperture. FIG. 6. Upper view of the same example. After Meek. CARINIFEX (VORTICIFEX) TRYONI M. (Pago 448.) FIG. 7. Lateral view, natural size, showing the aperture. FIG. 8. Upper view of the same example. FIG. 9. Under view of the same. After Meek. ANCYLUS UNDULATUS M. (Page 451.) FIG. 10. Upper view and lateral outline, natural size. After Meek. SPH^RIUM RUGOSUM M. (Page 440.) FIG. 11. An example of not quite adult size, enlarged two diameters. FIG. 12. A larger example, enlarged two diameters. FIG. 13. Outline showing the convexity of the valves. After Meek. SPILERIUM IDAHOENSE M. (Page 440.) FIG. 14. An imperfect example, natural size. FIG. 15. Outline showing the convexity of the valves. After Meek. PLANORBIS VETUSTUS Meek & Haydeu. (Page 448.) FIG. 16. Under view, natural size. FIG. 17. Upper view of the same example, enlarged. FIG. 18. Peripheral view of the same, more enlarged. After Meek. PLANORBIS LEIDYI M. & H. (Page 448.) FIG. 19. Upper view, natural size. FIG. 20. Peripheral view of the same, enlarged, showing the aperture. FIG. 21. Under view of the same, less enlarged. After Meek. PLANORBIS NEBRASCENSIS Evans & Shumard. (Page 448.) FIG. 22. Upper view, natural size. FIG. 23. Peripheral view of the same, enlarged. After Meek. 550 NON-MARINE FOSSIL MOLLUSCA. PLANORBIS LUNATA Conrad. (Pago 448.) FIGS. 24 and 25. Copies of Conrad's original figures. LIMN^EA MEEKII Evans & Shnmard. (Page 446.) FI-G. 2(>. Lateral view of a largo example, natural size. FIG. 27. Opposite view of a smaller example. After Meek. LIMN^A SIIUMARDI Meek & Haydcn. (Page 446.) FIG. 28. Lateral view, natural size. FIG. 29. Opposite view of the same. After Meek. (PoLYiuiYTis) KiNGii Meek. (Pago 446.) FIGS. 30 and 31. Copies of Meek's original figures, natural size. HELIX LEIDYI Hall & Meek. (Page 455.) FIG. 32. Lateral view, natural size. FIG. 33. Apical view of the same example. After Meek. HELIX (ZONITES) MARGINICOLA C. (Pago 453.) FIG. 34. Copy of Conrad's original figure. PHYSA SECALIXA E. & S. (Page 450.) FIG. 35. Lateral view, natural size. FIG. 36. Opposite view of the same. After Meek. LATIA DALLII White. (Page 451.) FIG. 37. Dorsal view, natural size. FIG. 38. Lateral view of the same example. FIG. 39. Dorsal view of another example. FIG. 40. Similar view of another example, showing a portion of the shell broken away, revealing the large lunate shelf extending forward from the beak. IISTDEX. Page. Abstract of report on geology of the Eureka District, Nov., by Arnold Hague 237 Accompanying papers 43 Acid rocks of Keweenaw Series, Origin of. 125 Acrotreta gemma 258, 259, 2(31 — prospectensis 256 Administrative report of chiefs of divis- ions and heads of parties 1 Affinities of Hesperornis 68 Agassiz, Alexander, referred to 153 A gate Bay group of the Keweenaw Series 116, 145, 187 , Minnesota 108,117 — Harbor, Keweenaw Point, Mich 17 G Agnostus bidens 258,259,261 — communis 257, 258, 259, 261 — neon 258,259,261 — prolongus 259 — richmondcnsis 258 — scclusus 258 — tumidosus • 259 — tumifrons 259 Ajjogebic Lake, Mich 136, 147, 163, 165 Albany and Boston conglomerate 114, 131 Algoma Mine, Canada 159 A lhambra Hills, Basalt of 286 AllomzMine, Mich 121 Alpha Peak, Altitude of 246 Altamont moraine 378,388,393 American Museum of Natural History, Continued courtesies of the xvii Amygdaloids of the Keweenaw Series de- scribed - 116 Analyses of brine from Lake Lahontan Basin 226 river water given by Bischof 212 tho water of Great Salt Lake 212 tufa from Lake Lahontan Basin 216 Anclyus undulate 451 Ancylidae 451 Andesitic pearlites, Position of 281 Auimikio group 124, 135, 157 .Apparent thickness of, in Thunder Bay region 160 at Grand Portage Bay, Minn 143, 157 at Pokcgama Falls, Minn 161 , Coarse gabbro dikes of, on Pigeon Point and Thunder Bay 1 58 , Dikes in the 158, 160 , Intel bedded eruptives of 158, 163 in tho Mesabi Range, Minn 161 , Magnetitic beds of 161 on Pigeon Point 141, 158 Aniinikie group on the Kaministiquia, River, Canada Saint Louis River, Minn , Relation of, to Keweenaw Series . . . , Similarity of, to Penokee Huvoniau . — rocks of Guuflint Lake, Minn Anodonta ? angustata — ? catskillensis — decurtata — parallela — propatoris — in Lake Lahontan Basin Anomia gryphorhynchus — micronema — propatoris Anomiidae Anorthite in augite-andesite — rock of Keweenaw Series described. .. Antelope Hills Anthracopupa ohioensis Apatornis Apostle Islands, Wis Archceopteryx compared with Hesperor- nis and Ichthyornis Arethusina americana Arionidae Artesian water on the plains Asaphus gigas Asar defined Ashbed diabase of Keweenaw described. "Ashbed" of Keweenaw Point, Mich. 109, Assistants, chief, Monographs neai ly com- pleted by the — , — , Workoftho Athyris subtilita Atlantic mine, Mich Atlas of the Eureka District Atrypa Peak, Altitude of , Devonian of Atrypa reticularis Augite-andesite, Eureka District 281, 283, of Cliff Hills..... — — , Richmond Mountain Augite-syenite described Auriculida) Australia, Terraces on the coast of Babylon Hills, Devonian limestone of Bad River country, Wis..H5, 119, 122, 130, 174, 177, gabbros,. Relations of, to Huronian. . region, Great thinning of rocks in . . , Wis., Coarse gabbros of (551) Page. 158 162 135, 157, 163 158 159,161 424 424 479 429 429 221 422 242 422 421 278 97 388, 393 456 69 133, 155 £3 259, 261 452 xvi 262 299 108 119, 127 xv xvii 269 182 242 246 266 266 277, L'80 287, 290 282 278, 282 114 443 207 267 134, 136, 180, 18G 135 163 134 552 INDEX. Page. Baptism River, Minn 127, 143, 145 , — , Quartz-porphyry of 127 Bare Hills of Keweenaw Point, Mich 130 Barrier, Description of a 207 Bars and embankments built by Lake Lahontan 210,211 Barus, Dr. Carl, Important work under- taken by xvii Basalt dikes in Richmond Mountain 286 — , Eureka District 277, 280, 283, 284, 286, 290 — of Alhambra Hills 286 Basic flows of Keweenaw Series, Lateral extent of 121 — rocks of Keweenaw Series, Chrono- logic relations of, to acid rocks of the same 128 , Origin of 120 , Proofs of contemporaneous formation of 121 Basin of Lake Superior, Structure of the. 174 Basin Range Structure (Fig. 44) 196, 202 — , The Great (See Great Basin). Bat chewanung Bay, Canada 171,187 Battle Islands, Canada 141 Ray field county, Wis 155,175 Beach ridges 299 Bead Island, Canada, 114 Beaver Bay, Minn 114,126,143 Becker, G. F., Administrative report of.. 24 Beds, Sedimentary, in Lake Lahontan . . . 222, 224 Bell, R., on the Animikie group 160 , referred to 158,162,169,171 Berg till 297 Bete Grise Bay, Mich 108, 140, 148, 152 Bien, Morris, Services performed by 243 Bigsby, Dr., cited 385 Billings, E., cited 257 Birds, Cretaceous ; aquatic 85 — , Existing, without teeth 49 — , Geological horizon of 50 — incapable of flight 67 — , Oldest known 49 -, Origin of 86 — related to reptiles 51 — , Remains of, rare 49 — , toothed, Classification of 86 — with teeth, by Prof. O. C. Marsh 45 , Geological horizon of 50 Bischof, Analyses of river water by 212 Black and Nipigon Bays, Canada, Rocks of peninsula between 141 — Bay, Canada 129,137,176 , Thickness of Keweenawan rocks of 137 — River, Mich ". 152,177 ,Wis 150 Bohemian Mountain, Mich 105 — Range of Keweenaw Point, Mich . . .93, 126, 139, 153, 185 Bois Blanc Lake, Minn., Crystalline schists of 169 Bonneville, Lake, Extent of 202 Bowlderets defined 324 Bowlders, Trains of 320 Brain growth, General law of 57 P age. Brain of Hespcrorni* 55 Ichthyornis 71 Brine from Lake Lahontan Basin, Analyses of 226 Brooks, T.B., referred to 166,171 Brule Lake. Minn 186 region, Gabbro of 135 Brule River, Minn 126,144 , Felsitesof 144 Brunschweiler River, Wis 133 Brush Peak, Devonian formations of 266 Buffalo Salt Works, Nev., Analysis of brine from 226 , Description of the 225, 226 , Production of the 226 Bulimus floridanus 454 Bulinus atavus 450 — disjunctus 451 — longiusculus 451 — rhomboideus 451 — sublongatug 450 Bull- whacker Mine, Quartz-porphyry dike in 274 Burlington Bay, Minn 143 Bythinclla gregaria 466 Calumet and Hecla Mine, Mich 130, 180 Cambrian rocks, Thickness of, in Nevada. 254 Campeloma macrospira 4 69 — multilineata 469 — multistriata 469 —producta 469 — vetula 469 Canaday, David, cited . 381 Cape Choyye, Lake Superior 177 — Garguntua, Lake Superior 177 Carbon Ridge and Spring Hill group 251 Carboniferous rocks of Eureka District. . 268 Caribou Island, Lake Superior 133 , Thunder Bay, Canada 133 Carinifex ( Vorticifex) binneyi 448 — — tryoni 448 Carlton's Peak, Minn. 105 Carp Lake, Minn 123 Carson and Humboldt Sink, Description of the 225 Cascade River, Minn 144 Cassiopella turricula 464 Cercocarpus lardifolius 246 Ceriphasidiice 462 Cerithiidce 459 Cerithiiea 1 nebrascensis 463 Chamborlin, Prof. T. C., Administrative report of 17 .Examination of glacial moraines by xvii,17 , Preliminary paper on the ter- minal moraines of the Second Glacial Epoch, by. 291 , referred to 93,139,174,175 Chaquamegon Bay, "Wis 155 Chariocephalus tumifrons 258 Chauvenet, W. M., referred to 126 Chemical deposits of Lake Lahoutan 211 Chester, Prof. A. H., on the Mesabi Iron Range, Minn 161,170 INDEX. 553 Page. Chester, Prof. A. H., on the Vennillion Lake region of Minnesota 169 Chief geologic assistants, Monographs nearly completed by the xv , Work of the xv Chippewa glacier 381 Chonet es granulifera 269 — scitula 266 — verneuiliana 269 Clark, F. A., Services performed by 243 Classification of toothed birds 86 Cliff Hills, Augite-andesite of 282 Climate of the Great Basin 196, 232 — , Quaternary, recorded by Lake Lahontan 230 Clinton Point, Wis 155, 175 Cloquet River, Minn 126, 142 Coarse gabbro of Keweenaw Series, Ori- gin of 125 Coast moraines 379 Colorado Plateau region, Map of the xv , Topographic material pertaining to the xvi unrivaled for the study of impor- tant problems xv . Work in the xv, xvi — , Work in xvi Columna teres 454 — vermicula .„ 454 Comb's Mountain, Devonian formations of 266 Commingling of Carboniferous fauna in N. Mex., Col., and Utah 269 Comparison of Hesperornis with Archceop- teryx 83 Ichthyornis with Archceopteryx 83 Conchifera 420 Conglomerates of Keweenaw Series de- scribed 98 Conocephalites bellus 258 — breviceps 259 — dissimilis 258 — laticeps 258 — linnarssoni 258 — pernasutus 258 — prospectensis 257 Conrad, T. A., Description of fossil Uniones by 479 Cook, G.H., cited 302,345 Copper-bearing rocks of Lake Superior, by R.D.Irving 89 , Former studies of 93 , Obstacles to the study of. 93 Copper deposits of Lake Superior 180 Ontonagou region, Mich 182 1 Origin of 184 - Harbor, Keweenaw Point 131, 176 — in Saint Croix Valley, Wis 187 — in Wisconsin 187 — mining in Michigan 186 — on Isle Royale 188 the Minnesota coast of Lake Superior 187 — Range, Douglas County, "Wis 156 , South, Mich 122 — , Rules to guide explorers for, in Lake Superior region 185 Corbicula augheyi 438 Page. Corbicula berthoudi 438 — cleburni 437 — cytheriformis 437 — nebrascensis 437 — obesa 437 — occidentalis 437 — subelliptica 437 — umbonella 438 — (Leptesthes) cardinceformis 437 fracta 439 macropistha 437 planumbona 437 — (Veloritina) durkeei 437 Corbula crassatteliformis 442 — englemanni 442 — mactriformis 442 — perundata 442 — pyriformis 441 — subtrigonalis 442 — tropidophora 442 — undifera 442 var. subundifera 442 Corbulidse 441 Cordaites in White Pine shale 267 Coteau des prairies 389 — du Missouri 394 Crepicephalus affinis 259, 261 — gallatinensis 258, 259, 261 — granulosus 259,261 — larviceps 258 — occidentalis 258 — aimilis .' 258 — simulatus 259 — unisulcatus 258, 259, 261 Cretaceous birds ; aquatic 85 Cross River, Minn 143 Crystalline schists in the Lake Superior region of doubtful geological posi- tion 168 of Bois Blanc Lake, Minn 169 Dog Lake, Canada 168 east shore of Lake Superior 171 Rainy Lake 169 Saganaga Lake 169 the Marquette and Menominee re- gions, Mich 166 Wisconsin River Valley 171 Vennillion Lake, Minn 162, 169 Cupriferous amygdaloids of the Keweo- naw Series 181 — conglomerate s of the Keweenaw Series - 1 80 — veins of the Keweenaw Series 183 Current River, Thunder Bay, Canada 159 Currents, shore, Action of 207, 208 Curtis.J. S., Work of. Curve exhibiting the rise and fall of Lake Lahontan (Fig. 51) 221 Curves exhibiting the oscillations of La- hontan climate (Figs. 55, 56) 231 Cyrena carletoni 436 — dakotensis 436 Cyrenidse 435 Dacite, Eureka District 277, 280, 282, 284 Dakota, eastern, Topographic features of . 393 — , — Moraines of 394 554 INDEX. Page. Dakota Valley glacier 393 Dalles of Saiut Croix River, Wis 175 Dana, J. D., cited 305 Dawson, G. M., cited 313, 385, 398, 399 Dawsonella meeki 453 Dead Sea, Salinity of the 212 Deltas, Terrace 304 Dendritic tufa in Lake Labontan Basin .. 214,215 Denver, Soils near, investigated Deposits, Saline, of Lake Lahontau 224, 230 — Sedimentary, in Lake Lahontaii 221 — Tufa, ofLakoLaLoutau 212 Description of Heaperornis 52 Ichthyornis 69 Desiccation products of Lake Lahontan . . 224 Detrital rocks of Keweenaw Series 97, 114 , Origin of 100 Devil's Track River, Minn 130 Devonian fossils in the Mackenzie River Basin 265 — rocks of Eureka District 264 Diabase-porphyrite of Keweenaw Series described 108 Diabases of Keweeuaw Series described. . 97 Diamond Mountains, Geology of 251 — Peak, Altitudeof 246 quartzite 268 — Range, Position of 245 — Valley 245 Dicellocephalus angustifrons 259 — lilobatus 259 — expansui 258 —finalis 261 —flabellifer 261 — marica 259 — nasutus 258,259 — osceola 259 — quadriceps 257, 258 — richmondensis 258 Dikes in tbe Keeweenaw Series 124 — of Auimikie group on Pigeon Point, Minn 158 ThunderBay 158 Director, Report of the xv Dog Lake, Canada 168 Dome, tufa, Section of a, in Lake Lahontan Basin (Fig. 50) 219 Domes and towers of tufa built by Lake Lahontau 216 Douglas County, Wis 137, 155, 156, 174, 176, 179 , Copper of 187 Douglas lloughton River, Keweenaw Point 151,153 Drift, Classification of- 296 — features of eastern Dakota 393 — , shore, Nature of 207 Driftkss area 318 Duluth beds of Keweenaw Series 134 — , Minn., Coarse gabbro of 142 , Rocks of 105, 110, 114, 119, 124, 134, 142, 175, 185 Dwight, W. B., cited 365 Eagle Harbor, Keweenaw Point, Mich.. 176 — Mountain, Minn., Augite-syenite of ... 120 — Salt Works, Nev., Analysis of brine from .. 227 Page. Eagle Salt Works, Nev., description of the 226 , Profile of reservoir and vats at 227 , Yield of 227 East Humboldt Mountains 245 — shore of Lake Superior, Crystalline fohistsof 171 , Keweenawan rocks of 140 Eastern sandstone between Bete Griso Bay and Lake Agogobic 147 , Different views as to its relation to the Keweenaw Series 152 east of Keweenaw Bay 147 , Former supposed Triassic ago of . . 148 , Geologic position of 147 — of LakeSupeiior 136,147 on Keweenaw Point 147 , Phenomena of contact of, with Keweenawau rocks 148 , Quarry in, on the Torch Lake Rail- road 151 , Relations of, to Keweenawan rocks 152 Series 147 Embankments, shore, Ideal plat illustrat- ing (Fig. 46) 207 , The formation of 206 Emmons, S. F., Administrative report of. . 22 , cited ...'. 257,265 , Work of xvi Englacial till denned 397 Eolian deposits 304 Erie glacier, Western Moraine of 330 Eskers defined 299 Euomphalus subrugosus 269 Eureka district, Cambrian rocks of 254 , Carboniferous rocks of 268 , Climateof 246 , Devonian rocks of 264 , Diamond Peak, Quartzito of 253, 268 • — , Eureka quartzito of 253, 262 , Hamburg limestone of 253, 255 , — shale of 253,255 , Geologic work in xvi , Geologic sections in 288 , Granite of 273 , Granite porphyry of 274 , Lone Mount limestone of 253, 262 , Lower coal-measures of 253, 268 , Mode of occurrence of volcanic rocks in 280 , Nevada limestone of 253,264 , Paleozoic formations of 248 , — section of 251, 253 , Pogonip limestone of 253, 200 , Position of 244 , Pro-Tertiary igneous rocks of 273 , Prospect Mountain limestone of 253 — , quartzite of 253 , Quartz porphyry 273 , Relative age of volcanic rocks of ... 281 , Secret Canon shale of 2;>3, 255 , Silurian rocks of 2CO - — , Tertiary and post-Tertiary volcanic rocksof 277 , Upper coal-measures of 253, 270 , Weber conglomerate of 253, 270 INDEX. 555 Page. . Eureka district, White Pine shale of ..... 253, 266 — Milling district, Development of ...... 247 — quart zite .............................. 262 Exchange of publications provided for by law .................................... xvii Existing birds without teeth ............. 49 Expenditures during the fiscal year ...... xvii Fault on Keweenaw Point, Mich ......... 179 —, The Keweenaw ....................... 139.150 Faulting, Recent, in the Great Basin ____ 232 Faults at Porcupine Mountains, Mich ... 179 . — in Douglas County, Wis ............... 179 — on Lake Superior ..................... 1 79 Feet of Hesperornis ...................... 62 -- Ichthyomis .......................... 77 Felsitc of Cascade River, Minn .......... 144 — Devil's Track River, 'Minn .......... 130 - -- Mt. Houghton, Keweenaw Point, Mich ............................. 130 Felsitic porphyries of Koweeuaw Series described .............................. 113 Fenestella (Sp. ?) .......................... 269 Field work, Synopsis of .................. xv Financial statement for the fiscal year. . . xvii Finger Lake glacier ...................... 333 Fish Creek Mountains .... ............... 249 -- Valley .............................. 245 Floe till defined ............... v .......... 297 Flo wage, Indications of, in basic rocks of Kewoenaw Series ................. ..... 118,120 Fluidal structure in amygdaloids of Ke- weenaw Series ................... - - - 118 — texture in quartz-porphyry of Kewee- naw Series ........................... 126 ' Fond du Lac, Minn., Sandstone of ....... 141 Forest beds .............................. 340 Fort Wingate, N. Mex., Base line meas- ured near ................. ............ xvi Fossil lakes, Discovery of, in Nevada, Cal- ifornia, and Oregon. .............. 195 -- , The smaller, of the Great Basin .... 234 — plants collected by L. F. Ward ........ xvi Fossils, invertebrate, Collection of, by Dr. C. A. White ............................ xvi Foster and Whitney referred to .......... 130, 148, 149, 15?, 174, 180, 182 Fourteen Mile Point, Lake Superior ..... 177 French River, Minn ............. - ..... 117, 142, 188 Gabbro, Coarse, of Duluth, Minn ........ 134 Gabbros of Keweenaw Series described. . 102, 104 Garnet iu rhyolite ........................ Gary moraine ........................ 378, 388, 333 Gasteropod shells in Lake Lahontan de- posits ....................... 213,221,22; Gasteropoda ............................. Gaylussite in Lake Lahontan Basin ..... Geddes and Bertram! Mine, Rhyolite of. . Gcikie, James, cited . .................... 307 General law of brain growth ............. Genesee glacier, Moraine of .............. Geographic distribution of Devonianfauna ___ volcanic rocks of Eureka District. 280 Geologic differences between augitc-ande- site and basalt ....................... — horizon of Odoutornithes ........... : - • 284 Page. Geology of the Eureka District 237 Georgia slates of Vermont 257 Gilbei t, G. K , Administrative report of . . 14 cited respecting drift 331, 333, 335, 338 , Paper on Lake Lahontan revised and edited by 195 referred to 131 suggests how salt lakes may be- come fresh without overflowing . 199, 229 Glacial corrasion 355 — epoch, second, Terminal moraine of ... 291 — movements in Dakota 389 the Finger Lake region 358 Grand River region 342 Green Bay region 318 Hudson Valley region 373 Lake Michigan region 325 Lake Superior region 387 Maumee region 333 Mohawk region 361 Minnesota region 392 Saginaw region 330 Scioto region 340 .Law of 320 Gneiss of Lake Superior region 168 Thunder Bay, Canada 161 Golden, Colo., Geology of the vicinity of. Ooniobasis arcta 464 — carteri 464 — chrysalis 462 — chrysalloidea 462 — cleburni 462 — columinis 464 — convexa 463 var. impressa 463 — endlichi 463 — gracilenta 463 — invenusta 463 — macilenta 462 — nebrascensis 463 — nodulifera 464 — fomitta 463 — simpsoni 464 — sublaevis .. 463 — tsubtortuosa 463 — tenera 464 — tenuicarinata 463 Gore, J. Howard, Administrative report of 30 Goose Point, Thunder Bay, Canada 159 Grand Marais, Minn 123, 144, 177 — Portage Bay, Minn 135,141,143,157 , Animikie slates of 143,157 , Dikes of 141 — River glacier 341 — Traverse glacier 326 Granite, Eureka District 273 — of Keweenaw Series described 1 14 Granite-porphyry, A go of 274 ( Composition of 275 , Eureka District 274 Granitoll of Keweenaw Series described 114 Granitic porphyry of Keweenaw Series described 114 Graptalites in Pogouip limestone 261 Gratiot River, Keweenaw Point, Mich 119, 139, 149 556 INDEX. Page. Great Basin, the, Altitude of 196 , Barrenness of 196,199 , Climate of 196,232 , Description of 196 , Form of 202 , Geologic attractiveness of 201 , Industries of 201 , Lakes of 197,201 , Mountains of 196, 200, 202 ,Oasesin 199 , Present orographic movements in . 232 , Quaternary climate of 231 , Rainfall of 196,199 , Rivers of 197 , Scenery of 196,199 , Seasonsin 200 , Size of 196 , Storms in the uplands of 200 , The smaller fossil lakes of 234 , Topography of 196 , Valleysof 197,202 ; why so called 196 Great Palisades of the Minnesota coast 105. 113, 114 , Quartz-porphyry of the 126 , Relations of acid and basic rocks at. 126 — Salt Lake, Analyses of the water of . . 212 Green Bay glacier 314 Greenstone group, The, of Keweenaw Point 133 — , The, of Keweenaw Point 121, 131, 183, 186 Gros Cap, Lake Superior 178 Growth, brain, General law of 57 Gunflint Lake, Minn 159,161 Habits of Hesperornis 65 Ichthyornis 82 Hague, Arnold, Abstract report on Ge- ology of the Eureka District, Nov., by 237 , Administrative report of 10 , "Work of xvi Halysites 263,266 Hamburg limestone — •halo Hclicidae Helix evangtonensi« — kanabensis. — leidyi , — peripheria — riparia — ? veterna — ? vetugta — (Zonites) marginicola Hfsperornis, Affinities of — , Brain of — , Comparison of, with Archceopteryx . . . — , Description of — , Habits of — , Legs and feet of — , Locomotion of — , Origin of peculiar features of — , Pelvic arch of — , Reptilian ancestry of — , Restoration of — , Ribs of — , Scapular arch of 255 255 453 454 454 455 555 455 454 454 453 C8 55 83 52 65 62 67 65 60 66 64 59 57 Hesperornis, Size of —.Tail of — , Teeth of — •, Vertebra} of — , "Wings of Highland Range, Age of History, Sketch of the geologic, of Lake Lahontan Hitchcock, C. H Hoosac fault , Volcanic rocks of Hornblende-andesite, Eureka District . . . Hornbleude-gabbro of Keweenaw Series described Hornitos Cone, Geology of Hot Springs associated with lines of recent faulting in the Great Basin , Tufa deposits of Houghton, Douglas, referred to — Mount, Keweenaw Point, Mich House Range, Pogonip limestone of Howell, E. E., cited Hudson Valley moraine Hungarian River, Keweenaw Point Hunt, T. S., on the Animikie group referred to 124, Huron Bay, Lake Superior Huronian (Animikie group).. .. 124, 135, — , Comparison of basic eruptives of the, with those of the Keweenaw Series. — , Confused use of the term — of the Alarquette and Menouiiuco regions of Michigan Penokee region, "Wisconsin — , Relations of the, in general to the Ko- weenaw Series — , Relations of the, to synclinal — The original. , Eruptives of , Relations of, to the Anhnikio group Hyalina ? evansi — / occidentalis Bydrobia anthonyi — ? eulimoides — recta — subconica — utahensis . . . Page. 65 61 52 57 — warrenana Byolites primordialis Ichthyornis, Brain of — , Comparison of, with Archceopteryx — , Description of — , Habitsof — , Legs and feet of — , Pelvic arch of — , Reptilian features of — , Restoration of — , Scapular arch of — , Skull of —.Tail of — , Teeth of — , Vertebra} of. . . 195 306 288 280 277, 280 284, 289 105 284 232 219 148 130 261 256 366 149, 154 162 135. 162 147, 177 141, 143, 157. 163 172 156 166 165 171 175, 179 1C3 164 164 452 470 465 465 466 406 466 465 258, 259 71 83 69 82 77 75 79 77 73 70 76 71 73 INDEX. 557 Page. Irhthyornis, Wingsot 75 Iddiugs, Joseph P. , cited 242, 278, 285 , Microscopic petrography of Eu- reka District, by 242 Illustrations, List of xi Interlobate moraines defined 301,313 described. . .315, 323, 328, 330, 339, 341, 351, 373, 380, 382, 384, 397 Intermediate moraines. (See Interlobate moraines. ) Investigations initiated xv Iphidea depressa 258 Irving, R. D., cited in respect to terminal moraines 316 on copper-bearing rocks of Lake Superior 89 Isbister, A. K., cited 265 Isle Royale, Mich 137,141,174,177,183 .Copperon 188 , Relation of rocks of, to rocks of Minnesota coast 141 , Thickness of Keweenawan rocks of 137 Juniperus occidentalis 246 Kakabika Falls, Canada 159 Kamosdifined 299 Kaministiquia River, Canada 158, 159 , Animikie group on 158 Kanab Canon, Paleozoic section of 272 Kettle moraine synonymous with term- inal moraine of the second glacial epoch. 291 — Range 321 — River.Minn 187 Kettles 311 KeweenawBay 140,147,148,177 — Fault 139,154,155 - — , Foster and "Whitney's view as to ... 154 — Point, Mich 114,115, 117, 119, 121, 123, 130, 136, 139, 174 , Ashbedof 109,119,127 ,BareHillsof ,. 139 , Bohemian Range of 93, 126, 139, 153 , Eastern sandstone on 148 ,Faulton 139,179 , Great conglomerate of 121 , Greenstone group of 133 , Outer conglomerate of 131, 1 32 , Southern range of 93 1 The ashbed of 109 , The greenstone of ... 107, 121, 131, 183, 186 , Thickness of rocks of 136 , Topography of 123 — Series, Absence of volcanic ash from ... 1 00 , Agate Bay group of 116,145,187 , Alterations of diabase of 106 oli vinitic diabase of 108 , Amygdaloids of 110,116 , Amy gdules of amygdaloids of 117 , Anorthite rock of 97,105 , Ashbed-diabase of 108 .Ashbedsof 98 , Augitc-syenite of 100,111,114 , Basic rocks of 97,101 Page. Keweenaw Series, Chronologic relation of eruptive rocks of 100, 128 , Classification of basic rocks of 102 , Coarse gabbros of 122, 124 .Comparison of basic eruptivos of, with those of the Huronian 172 .Composition of . 97 , Conglomerates of 98 .Contact of, with western sandstone in Douglas County, "Wis 150 , Copper deposits of 180 , Cupriferous araygdaloids of 181 conglomerates of 180 veins of 183 .Detrital rocks of 97,114 .Diabase of 97 , Diabase-porphyrite of, described 108 , Different views as to the relations of, to eastern sandstone 152 , Dikes of 100, 124 , Distribution of upper division of. ... 132 , Duluth group of 134 .Effect on topography of basic rocks of 123 , Extent and general nature of 95 .Felsitesof 100,111,113 , Fluidal texture in amy gdaloids of . . 118 , Formation of coarse gabbros of 125 .Gabbroof. 102,104 , General stratigraphy of 132 , Geologic position of '. 173 .Granite of 100,111,114 , Granitellof 111,114 , Granitic porphyry of 100, 111, 114 , Hornblende-gabbro of 105 in Canada 95 , Indications of flowage in acid rocks of 126 , basic rocks of 120 in Michigan 95 Minnesota 95 theNipigon Basin 96 , Intrusive augite-syenite of 125 , — granite of 125 in Wisconsin 95 , Lateral extent of basic flows of 121 , Lava flows of 97,100 ,Lithologyof 101 , Olivine-diabase of 102,107 , Olivine-free diabase of 106 , Olivine-gabbro of 102 , Olivinitic diabase or melaphyr 107 on the north and east coasts of Lake Superior 140 south shore of Lake Superior . . 139 , Original acid rocks of . 99, 111 .Origin of acid rocks of 130 , basic rocks of 120 , coarse gabbro of 125 , detrital rocks of 100 , Orthoclase-f ree diabase of 102 , Orthoclase-gabbro of 104 , Proof of contemporaneousness of basic rocks of 121 , Pseudamygdaloids of 106, 116 , Quartziferous porphyry of 99, 111, 113 558 INDEX. Page. Keweenaw Series, Quartzless porhyry of. Ill .Relations of, to the Animikie group 135, 157, 163 , , associated formations 1 47 , , eastern sandstone 147 — , , Iluronian . 171 , , newer formations 147 , Sandstones of 98 , Source of basic rocks of 124 , detrital material of 99 , Stratiform amygdaloids of 118 , Stratigraphy of lower division of. . . 133 , Structural features of detrital rocks of 131 , three classes of rocks of 116 — —. — relations of, to the Huronian in Nipigon Basin 173 , Summary view of original rocks of. . 114 , Superposition of, on the Animikie •lates on Thunder Bay 159 , Thickness of beds of basic rocks of.. 122 , lower division of 136 , . upper division of 132 , Topographic effect of basic rocks of. 123 , Two divisions of 132 , Warped bedding of lava flows of . . ]20 King, Clarence, Administrative report of. 3 cited in respect to terminal moraine . 346 , "Work under direction of xvii King, F. H., cited , 357, 387, 398, 400 Kinnicut, Robert, cited 265 Knife River, Minnesota 116 Kutorgina minutissima 258, 259 — wJiitfiddi 258 Laboratory facilities afforded by National Museum and American Museum of Nat- ural History xvii Lac La Belle, Michigan 105,150 Lacustrine deposits associated with ter- minal moraine 298, 321, 329, 350 Labontan, Lake. (See Lake Lahonton.) , Lakebedsof 222 Lake Bonneville, Extent of 202 — Erie glacier, Western 330 — Lahontan, Bars and embankments built by 210 , Chemical deposits of 211 , Curve exhibiting the rise and fall of. 221 , Dendritic tufa deposited by 214 , Desiccated bed of 203 , Desiccation products of 224 , Extent of 202 , Fluctuations of 205 , Hydrographic basin of 204 , Investigations relating to xvi .Lake-beds of 204,222 , Lithoid tufa deposited by 212 , Many questions yet to bo asked of. . 230 , Outlet of not found 205 , Oro graphic movements since epoch of 232 , Preliminary map of 204 , Profile of the shore of 209 , Quaternary climatic oscillations re- corded by 195,230 Tape. Lake Lahontan, Salt works in basin of. . . 225 , Sections of strata in 222 , Sedimentary deposits in 221 , Shore topography of 204,208 , Ske tch of the geologic history of . . 195 , Terraces carved by 205, 208 , Thinolitic tufa deposited by 213 , Tufa deposits of 212 , , Analyses of the 216 , , Succession of the 215 , ; what they teach 220 , Towers and domes built by 216 — Michigan glacier 322 — Superior Basin, Structure of 174 , Eastern sandstone of 136 glacier 382 synclinal 174 Lakes, Fossil, discovered and explored in Nevada, California, and Oregon 195, 201 — , Playa 198 — , Quaternary, of Great Basin, Study of. xvi — that overflowed into Lake Lahontan Basin 204 — , The modern, in Lake Lahontan Basin. 203 — , , are not remnants of the ancient lake 229 — , The smaller fossil, of the Great Basin. 234 — with and without outlet, Nature of 211 Lamb Island light, Cana-la 129 Laopteryx 49 Lapham, Dr. I. A., referred to 175 Latiadalltt 451 Laurentian, Confused application of the term, to rocks of the Lake Superior region 156 Lava flows of Minnesota coast, Warped bedding of 120 Lea, Dr. Isaac, describes fossil Uniones .. 478 Legs and feet of Hcsperornis 62 Ichthyornis 77 Letter of transmittal of Director's report. v Lenticular hills 306, 318 Leptcena sericea 202 Lester" River, Minn 142,145 group of Keweenaw Series 134 Lewis, H.C., cited 302,341,346 Library, Need of a technical working xvii Limncea (Acella) haldcmani 445 — ? compactilis 445 — (Limnopfiysa) nitidula •* . . 445 — meckii 446 — minuscula 446 — (Polyrhytis) kingii 446 — shumardi 446 — simihs 445 — retusta 445 Limnseidro 444 Linear topography 321, 353, 361, 364 Lingula manticula 258, 259, 261 Lingulepis mccra 258, 259, L'61 — mmutct 258,259,261 Lioplacodes •veternus 46G List of illustrations xi .species 472 Lithasia antiqua 465 559 Page. Lithoid tufa in Lake Lahontan Basin .... 212 Locomotion of Besperornis 67 Logan, Sir "W., on the Animikie group 160 — , , referred to 153, 156, 159, 160, 169, 171 — , W.E., cited 343 Lone Mountain ^limestone 262 Lower Coal-measure limestone of Eureka District 268 — copper-bearing group 124 — division of Keweenaw Series, Stratig- raphy of 133 , Thickness of ../. 136 Macfarlane, James, cited 355 Mac Farlaue, T. , referred to 137, 138, 162 McKay's Mountain, Canada... :.. 159 McKinlay, R., AVork done by, on South Copper Range of Michigan 152 Macrocyclis spatiosa 452 Macrodon tefiuistriata 270 Mahogany Hills 250 Main Trap Range of Michigan 130, 147, 177 Mamainse, Canada, Keweenawan rocks of. 124 , Thickness of Keweenawan rocks of. 1 38 — peninsula, Lake Superior 124, 137, 178 Mammillary hills 306 Manitou Island, Lake Superior 177 — River, Minn 144 Map of northern and central Nevada xvi the Colorado Plateau region xv Ten Mile Mining District, Colo . . xvi — , Preliminary, of Lake Lahontan 204 Margaritana nebrascensis 427 Marsh, Prof. O. C., Birds with Teeth, by. . 45 Marvine, A. R., referred to 115, 139, 178 Mather, W. W.} cited 380 Maumee glacier 330 Maxon, Rev. Dr 371 Meek, F. B., cited 256, 259, 265 Melampus ? antiqmts 444 Melania claibornensis 460 — decursa 479 — insculpta 460 — sculptilis 461 — subsculplilis * 461 — taylori 461 — wyomingensis 460 Nelaniidce 459 Melanopsis americana 461 Melaphyr of Keweenaw Series described- 107 Mesabi Range, Minn., Animikie group at. 161 , Drift relations of 384 , Magnetitic rocks of 162 Mica in andesi tic pearlites 282 Michipicoten Island, Lake Superior. .109, 114, 130, 137, 141, 171, 177 , , Thickness of Kewcenawan rocks of 137 Micropyrgus minutulus 465 Mineral Point, Quartz porphyry of 273 Mincralogic differences between augite- andesite and basalt 284 Minnesota Coast, Agate Bay beds of.. 116, 145, 187 , Beaver Bay group of . 145 , Copper on 187 , Dips and trends of rocks of 141 Page. Minnesota Coast, Duluth group of 145 , Great Palisades of 105, 113, 1 20 , Identity of rocks of, with those of Keweonaw Point 142 , Keweenawan rocks of 140 , Lester River group of 145 , Stratigraphy of Keweenawan rocks of 144 , Temperance River group of 146 , Thickness of Keweenawan rocks uf . 1 37 — mine, M ich 181 — valley glacier 388 Mission Creek, Minn 141 Missouri Coteau. 394 , Moraines of 396 Mode of occurrence of volcanic rocks in Eureka District 280 Modern lakes in Lake Lahontan Basin 203 Mohawk moraine 360 Monographs by chief assistants nearly completed x v Montreal River, Wis 117, 119,131, 136,155, 175, 180, 187 Moraine, Altamont 378, 388, 393 — of the Chippewa valley glacier 381 coast region 380 Dakota valley glacier 393 Finger Lake region 353 Genesee glacier 351 Grand River glacier 341 Traverse glacier 326 Green Bay glacier 314 Hudson Valley glacier 366 Lake Erie glacier, "Western 330 Michigan glacier 322 Superior glacier, Western 382 Maumeo glacier 330 Minnesota valley glacier 388 Missouri Coteau 396 Mohawk glacier 360 Saginaw glacier 327 Scioto glacier 338 — , Terminal, of the second glacial epoch, by T. C. Chamberlin 291 Moraines defined and classified 301 — , General distribution of 313 — , Intermediate or interlobate, defined .. 301,313 , described 315, 323, 328, 330, 339, 341, 351, 373, 380, 382, 384,397 —.Kettle, defined 310 —.Lateral 301,352,354 — , Medial 301 — , Modifications of, in ridged regions 344 — .Paperon 291 — . Peripheral, defined 302 — , — , cited 336,384,400 — , Relations of, to the margin of the drift . 314 — , Terminal, defined 302 — , — , described 310 — t — t of the second glacial epoch 310, 402 _, — , Possible course of, beyond present explorations 401 Morainic loops 313 , Special descriptions of 314 — spurs in western New York 348 560 INDEX. Page. Morton.Dr. S. G., describes fossil TTniones. 478 Mount Houghton, Keweenaw Point, Mich . 114 , , — , Felaiteof 130 Murray, Alexander, on the Huronian of Lake Huron and Lake Superior 163, 169, 171 Myalina subquadrata 270 Mytilidce 423 Naiadites carbonaria 425 — dongata 425 — leevis 425 National Museum, Continued courtesies of the xvii Neritidaj 457 Neritina bannisteri 458 — bruneri 459 — naticiformis 458 — nebrascensis 457 — (Velatella) baptista 458 bellatula 458 carditoides 458 volvilineata 458 Nevada limestone 264 — , Map of northern and central xvi — , Niagara, limestone in 263 — , "Workin xvi New investigations xv Newberry, Dr. J. S., cited 331, 336, 339, 343 Newman, G. Olivio, Services performed by 243 Niagara limestone in Nevada 263 Nipigon Bay, Canada 126, 177 , Thickness of Keweenawan rocks of 137 — Straits, Canada 129 Nonesuch belt, Mich 180 — cupriferous sandstone 185 — silver-bearing sandstone 139 North shore of Lake Superior, Distribu- tion of Keweenawan rocks on 143 , Distribution of rocks on ... 141 , Great exposures on 140 , Keweenawan rocks on 140 , Scenic characteristics of 140 Norwood, Dr. J. G., cited 385 — , , on the geology of the Min- nesota coastof Lake Superior. 118, 121, 124, 143, 158, 164 Numakagan Lake, Wisconsin 134, 165, 175 Oboletta discoidea 259,261 OdontolccB 50,86 Odontornithes, Geologic horizon of 50 Odontotormce 50, 69, 86 Office of the Survey, Location of the xvii — work, Synopsis of xv Ogyffia problematica 258 — spinosa 258 Old Suffolk mine, Keweenaw Point 113 Oldest known birds 49 Olenellus abnormig 256 — barrandi 256 — iddingri 256 — thompsoni 257 — vermontana 257 -shales 256,257 Page. Oli vine - diabase of Kewienaw Series described 102,107 Olivine-free diabase of Keweenaw Series described 106 Olivine - gabbro of Keweenaw Series described 102 Olivino in basalt 285,286 — , Relation of, to silica in basalt 286 Ontouagon River, Mich 130, 134, 136, 151 Oquirrh Range, Age of 256 Ore deposits of Eureka District, Study of xvi Origin of birds 86 peculiar features of Hesperornis 65 vertebral forms 79 Original rocks of Keweenaw Series, Sum- mary view of 114 Orographic movements, Post-Lahoiitan . . 232 probably in progress in the Great Basin *232 Orthis eurekensis 258 — macfarleni 265 — pecosi 270 — perveta 261 — testudinaria 261 — tricenaria 261 — tulliensis 266 Orthoclase-free diabase of Keweenaw Series described 102 Orthoclase-gabbro of Keweeuaw Scries described 104 Orton.E., cited 339,340 Osars 299 Ostrea glabra 421 — subtrigonalis 421 Ostreida? 420 Owen, D.D., referred to 147,174 Paleozoic formations in the Eureka Dis- trict 248 Palisade Creek, Minn 126 Papers accompanying the Director's report 43 Paracydas occidentalis 266 Pelvic arch of Hesperornis CO Ichthyornis 75 Penokee Huronian, Similarity of, to Ani- mikie group 158 — Iron Range, Wis 165 Petit Marais, Minn 143 PhUlipsia (sp. ?) 269 Physa bridgerensis 450 — carletoni 449 — copei 450 — felix 450 — pleromatis 450 — secalina 450 Physidso 449 Pic River, Canada 177 Pigeon Point, Minn., Animikie rocks of.. 141, 158 .Dikesof 158 — River, Minn 117,126,130,137 Pifion Range, Devonian limestone of 267 Pinto fault 289 , Volcanic rocks of 280 — Peak, Altitude of 246 , Rhyoliteof 279,282 INDEX. 5G1 Page. Pisidiidao 440 Pisidium saginatum 440 Plains marginal to moraiuo. . .303, 321, 324, 329, 340, 355, 378 Planorbis cequalis 448 — ( Bathyomphalus) amplexus 447 kanabensis 447 planoconvexus 447 — drratus 448 — convolutus 447 — (Gyraulus) militaris 447 — leidyi 448 — lunata 448 — ncbrascensis 448 — utahensis 447 van spectabilis 447 — veternus 446 -Bvetustus '. 448 Plant impressions in White Pino shalo. . . 266 Playalakos 198 (Plcurolvmnced) tenuicostata 445 Pleurotomaria sp. ? 270 Pogonip limestone 2CO Pointe aux Minos, Lake Superior 177 Pokegoma Falls, Minn 161 , — , Animikio Group at 161 , — , Maguetitie quartzite of 162 Polypora sp. ? 270 Poplar River, Minn 126,144 — , — , Felsitic porphyries of 144 Porcupine Mountains, Mich 93, 1 80 , — , Faults in 179 , _ Felsiteof 114,139 , — , Relation of the, to Koweenawau synclinal 175, 186 , — , Structure of 130,139 • — , — , Topography of 123 Portage Lake, Mich 121, 123, 150, 151, 180, 181 Post-Lahontan orographic movements 232, 233 Potato River, Wis 131 Potsdam sandstone of the Mississippi Valley 156 Power of flight of birds 87 Preliminary paper on the terminal mo- raine, by Prof. T. C. Chamberlin 291 Productus hallianus 266 — prattenianus 269 — punctatus 270 — semircticulatus 268 — shtimardianus 266 — subaculeatus 266 Profile of terrace and sea cliff (Fig. 45) ... 206 - the Lahontan lithoid terrace (Fig. 47) 209 Prospect Mountain limestone 254 quartzite 254 , Rhyolito dikes of 282 — Peak, Altitude of '. 246 — Ridge 248 Protospongia fencstrata 258 Prygvlifcra humerosa 460 Pseudamygdaloids of Keweenaw Series described 116 Psllophyton iu "White Pine shale 267 Ptilodictya carbonaria 270 — serrata <•• ...... 270 36 a Page. Ptychas2)is minuta 259 Publications, Exchange of, provided for xv bylaw xvii — , Preparation of Pumpelly, ft., referred to. 115, 117, 129, 151, 153, 178, 181, 184 — , Studies of the copper-bearing rocks of Lake Superior by 93,106, 111 Pupa arenula ... 456 — atavuncula 456 — bigsbyi 456 — incolata 456 — vermillionensis 456 — vetuata 456 Pupida3 455 Quartz in basalt 280 Quartz-porphyry, Age of 274 , Eureka District...".. 273 of Keweenaw Series 113 Quartzless-porphyries of Kcweenaw Series described 112 Quaternary climate recorded by Lake Lahontan 230 — formations, Classification of 295 — lakes of the Great Basin, Study of the. xvi Raer 299 Rainfall a potent factor in any region 199 — of t h e Great Basin 1 96, 1 99 Rainy Lake, Crystalline schists of 169 Read, M.C., cited 341,342 Read, Thomas J., Aid rendered by 243 Receptaculites mammillaris . 261 Reconnaissance, A geologic, in Nevada, California, and Oregon 195 Relative age of augite - andesito and basalt 284 rhyolite 284 dacite and rhy olito 283 rhyolite and basalt 284 volcanic rocks of Eureka District. 281,284 Remains of birds rare 49 Report, Administrative, of Clarence King 3 — , — , — Arnold Hague 10 — , — , —G.K.Gilbert 14 — , — , - T.C. Chamberlin 17 — , — , — S.F.Emmons 22 — , — , —G.F.Becker 24 _, _, _L.F.Ward 26 — , — , — J. Howard Gore 30 — , — , — Gilbert Thompson 32 Report of the Director xv Reptiles, Birds related to 51 Reptilian ancestry of Hesperurnis 66 — features of Ichthyornis 79 Rescue Canon, Rhyolite of 279, 282 — Hill, Devonian of 265 Restoration of Hespcrornis 64 Ichthyornis 77 Ketzia mormoni 270 Review of the non-marine fossil mollusca of North America by Dr. C. A. White. . 403, 550 Rhynchonella castcmca 265, 266 — eurekensis 269 Rhyolite, Eureka District 277, 279, 281, 284, 289 — , — — , Distribution of 282 562 INDEX. 444 59 Page. Rhyolite-pumice 277,284 Rhytophorus meekii 444 — priscu* Ribs of Hespfrornis Richmond Mine, Cambrian fossils inlime- stoneof 258 — Mount, Altitudeof 246 , Augite-andesito of 278, 282 Rickard, R. , Aid rendered by 243 Rise and fall of Lake Lahontan, Curre ex- hibiting the (Fig. 51) 221 Riseoidse 465 Roberts Teak Mountains, Devonian lime- stone of 267 Romiuger, Carl, cited 329 , referred to 147,148 Ruby Hill, Magnesiau limestone of 255 .Mines of 247 , Prospect Mountain, quartzite of 254 , Rhyoliteof 282 Russell, I. C., Sketch of the geologic his- tory of Lake Lahoutan, by 195 — , , Work of xvi Saganaga Lake, Crystalline schists of. ... 169 Sapinaw glacier 327 Saint Croix River, Wis 174,177 - , Kewe«-nawan rocks of. .123, 133, 137. 156 Valley, Wis 187 , — , Copper in 187 — Ignace Island, Lake Superior 126, 176 — John's ridge 332,338 — Louis Rirer.Minn 105, 137, 141, 144, 162, 175 , — , Animikie group on 162 — ,—, Coarse gab bro of 142,144 , — , Gabbro dikrs in slate of 162 , — , Red porphyries of 144 , — , Relations of Keweenawan and Huronian rocks on 142 ,— .Slates of 137,141,175 — Mary'sridge 336 River, Minn 103 Saline deposits of Lake Lahontan 224, 230 Salinity of Great Salt Lake 212 theDeadSea 212 Salisbury, R. I)., cited 350, 357, 360, 375 Salt-works in Lake Lahontan Basin 225, 228 Salts in Lake Lahoutau Basin 224, 230 Sand Spring Salt Works 227 Sandstones of Keweenasv Series 98 Sault Ste. Marie 140,176 Scapular arch of Hesperornis 57 Ichthyornis 73 Sccnrlla conica 257 Schell Creek Range, Pogonip limestone of. 261 Schizodiis cuneatus 269 Scioto glacier 338 Secret Cafion shale 255 Section, Generalized, of bank of Truckeo River near Indian Agency ... 223 — , — , — a tufa dome of Lake Lahontan Basin (Fig. 50) 219 — , Ideal, 'illustrating canons of Coraon River (Fig. 53) 224 — , — , of a spring deposit (Fig. 49) , , . 219 Page. Section, Ideal, of Basin Range Structure (Fig. 44) 202 — illustrating the relations of the Lahon- tan tufas (Fig. 48) 216 — of Quaternary strata at Mill City, Nov. (Fig. 52) 222 reservoir and vats ar Eagle Salt Works, Nev. (Fi-. 54) 227 Sedimentary deposits in Lake Lahontan . 221, 224 Selwyn; A. R. C. , referred to 124 Shells of fresh-water gasteropods in Lake Lahontan deposits 213,221,223 Shore currents, W ork of . 207 — drift, Nature of 207 embankments, Ideal plat illustrating (Fig. 46) 207 , T he formation of 206 SierraCanon, Dacite of WB Silica in augite-andesite, Percentage of . . 287 Silurian rocks, Eureka District 260 Silver Creek, Minn 110 — Islet Landing, Canada 160 Mine, Canada 161 — Mountain, Mich 139 Silverado and County Peak group 250 Size of Hesperornis 65 Sketch of the geologic history of Lake Lahontan, by I. C. Russell 189 Skull of Ichthyornis 70 Smock, J. C., cited 302, 345, 346, 369, 377 Snake River, Minn 187 Soils near Denver studied xvi South copper range, Mich 122, 147, 152, 155 — shore of Lake Superior, Keweenawan rocksof 139 , Scenic characteristics of ... 140 Sphcerium formosum 439 — idahoense 440 — planum 439 — recticardinale 439 — rugosum 440 — subellipticum 439 Spirifera camerata 269 — maid ^ 266 — pinonensis 266 — subumbona 266 Split Rock Rivor, Minn I0r», 116, 143, 145, 177 Spring deposit, Ideal section of a ( Fig. 49) 219 — Hill, Carboniferous fauna of 269 Spurious and doubtful species Stannard's Rock, Lake Superior .113, 139, 177, 179 , Quartzloss porphyry of 139 Stenotheca elongate, 258 Stevenson, J.J., cited 343 Stratiform amygdaloids of Koweeuaw Series described 118 Mrcptorhynchus chemunjensis 266 — crenutria 269 Striation, Glacial, in Dakota 399 — , — , - Finger Luke i\v !an 358 — — , — Grand Rivn-ivgion 342 — , — , — Green Bay region 318 — , — , — Hudson (western) region 374 — , — , — Lake Michigan region 325 — f — , Superior region 387 INDEX. 563 Page. Sttiation, Glacial, in Maumeo region. 333 - , — , — Minnesota Valley 392 — , — , — Mohawk Valley 3C3 — , — , — Scioto region 340 Stromatopura (sp. ?) 260 Strong, Moses, cited 387 — , — , on the copper-bearing rocks of Lake Superior 93,174,175 Strophites grandceva 455 Strophodonta perplana 266 Structural differences between augite- andesite and basalt 285 in granite-porphyry 275 Styliola fissurella 266 Subaqueous till. .297, 324, 329, 331, 336. 351, 355, 360, 362, 383, 386, 392 Sub-glacial till 296,321 fyiccinea ( Brachyspira) papillispira 457 Snccinidse 457 Superglacial till 297 Sweet, E.T., cited 381 on the copper-bearing rocks of Lake Superior 93, 139, 174, 175 Synclinal of Lake Superior. 174 between Isle Koyale and Ke- weenaw Point 174 in northern "Wisconsin 174 Synopsis of field and office work xv Syrinrjopora perelegans 266 Tail of Hcsperornis 61 Ichthyornis 76 Taylor, F. W., Chemical analyses of brines by 226 Teeth, Birdswith 45 — of Hesperornis 52 Ichthyornis 71 Tellimanya contracta 261 Temperance River group of Keweenaw Scries 187 , Minn „ 105,143 Ten Mile Mining district, Colorado, In- vestigations in xvi , — , Topographic map of xvi Terminal moraine, Paper on 291 Terrace and sea cliff, Profile of a ( Fig. 45) . 206 — , Profile of the Lahontan Lithoid (Fig. 47) 209 Terraces 303, 349, 351 — and embankments, The formation of. . 206 — cut by Lake Lahontan 208 ; what they teach 229 — on the coast of Australia 207 Tertiary and post-Tertiary volcanic rocks of Eureka District 277 Thaumastus limnceiformis 454 Thickness of paleozoic rocks of Eureka District 253 Kanab Cafion 272 Wahsatch Range 271 Thinolite in Lake Lahontan Basin 213 Thinolitic tufa in Lake Lahontan Basin . . 213 Thompson, Gilbert, Administrative re- port of 32 1 Geodetic and topographic work of. . xv Thompson, Minn., Animikie slates at 142 Page. Thunder Bay, Canada, Rocks of 135, 141, 158 , — , Sandstone of 35 , Lake Superior, Dikes of. 158 region, Coarse gabbro of 144 — Cape, Lake Superior 159 Till classified 296 — , Subaqueous, berg or floe. .297, 324, 329, 331, 336, 351, 355, 360, 362, 383, 386, 392 — , Subglacial 296,321 — , Suporglacial, englacial, or upper 297 Todd, J.E., cited 395,397,400 Topographic relations of the Grand River moraine - . 342 Green Bay moraine 316 Lake Michigan moraine ... 323 Maumee moraine 333 Minnesota moraine 389 Saginaw moraine 329 Scioto moraine 339 — types, Asar 307 , Beach 308 classified 304 , Drainage-erosion 305 , Dune 308 , Fluviatile 309 , Glacio-erosion 305 , Kame 307 , Lacustrine 308, 321, 329, 350 .Lenticular 306,318,321 , Linear 306, 318, 321, 353, 361, 364 , Mammillary 306,321 , Marine 308 , Morainic 307 , Orographic 305 , Till 306 Topography of eastern Dakota 393 shores 304 Torch Lake, Keweenaw Point 149, 151 Torrell, Otto, cited 297 Towers and domes of tufa built by Lake Lahontan 216 Trains of bowlders 320 Treasure Bill, Devonian limestone of . . . . 267 Trenton limestone in the northern penin- sula of Michigan 148 — species in the Lone Mountain limestone. 262 — Pogonip 261 Tridymite in augite^-andesite 278 Trinuclcus concentricu* 262 Tucubit Mountains, Devonian fishes of . . 265 , — limestone of 267 Tufa deposits of hot springs 219 Lake Lahontan 212 , Section illustrating the re- lations of the (Fig. 48) ... 216 ; what they teach 220,229 — from Lake Lahontau Basin, Analyses of 216 — , Physical conditions favorable to fonna- tionof 218 — towers and domes built by Lake La- hontan 216 Tulotoma thompsoni ». . . 467 Two Islands River, Minn 143 Tyler's Fork, Wis 114 564 INDEX. Page. Unconformity at top of Eureka quartzite . 262, 267 TTnio clavus 431 — aldrichi 433 — bettiplicatus 430 — brachyopisthus 433 — clinopisthus 434 — coucsii 432 — cristonensis 425 — cryptorhynchus 431 — dcweyanus — 431 — endlichi 432 — goinonotus 433 — goniambonatus 433 — haydeni 435 — holmesianus 433 — hubbardi 427 — mendax 433 — mucalis 426 — penultimus 427 — primcevus *. 432 — priscug 432 — proavitug 433 — propheticus 433 — senectus 432 — shoshonensis 435 — stewardi 426 — subspatulatus 431 — tellionoides 435 — retustus 430 — waahakiensis 435 Unonidso 424 Upham, Warren, cited 302, 346, 377, 378, 380, 383,384,387,388,392,39 Upper Coal-measure limestone of Eureka District 270 — division of the Keweenaw Seiies 131 Valley drift 302, 321, 350, 352, 355, 357, 360, 382 Valleys of the Great Basin occupied by Quaternary lakes 234 Valvata 1 montanaenaia 470 — ? nan a 470 — fscabrida 470 — ? subumbUicata 470 Valvatida) 470 Vanuxem, Larned, cited 352, 357, 364 Vermillion Lake.Minn.. Crystalline schists of.... 162,169 Vermont, Georgia slates of. .-> 257 Vertebra? of Hesperornis 57 Ichthyomis 73 Vertebral forms, Origin of 79 Vitrina obliqua 452 Vitrinida) 452 Viviparidjc 466 Viviparus conradi 467 — coutsii 467 — fjiUianus 466 — leai 467 — leidyi var. formosa, 467 — paludlneaformis 468 — panguitchensis 467 — pccnliaris 467 — plicapressug 407 — prudentius 467 — retusus 467 Page. Viviparus reynoldsianus 407 — trochiformis 467 — wyomingensis 4C8 Volcanic rocks of Eureka District, Agoof. 277 Volsella (Brachydontes) laticostata 423 regularis 423 Wadsworth, M. E., on the relation of east- ern sandstone of Lake Superior to the Keweenaw Series 1 54 — , , referred to 150, 153, 154 Wahhatch Range, Paleozoic section of . . 271 Walcott, Charles D., cited 257, 2C5, 269, 272 — , , on Devonian fishes in Kanab Canon 265 — , , Paleontology of the Eureka Dis- trict, by 242 Ward, L. F., Administrative report of. . . 26 , Paleontologic work of xvi Wave action on shores 200 Weber conglomerate of Eureka District. 270 Western sandstone at Fond du Lac, Minn 141 of Lake Superior 155 , Contact of, with Kowoenaw Series in Douglas Co., Wis. 156 , Equivalency of the, with the eastern sandstone 1 56 , Relation of the, to the Ko- weenaw Series 155 , , Mississippi Pots- dam 156 White, Dr. C. A., cited 259,269 in respect to terminal mo- raine 389,392 , Collection of invertebrate fos- sils by xvi . Review of the non-marine fos- sil mollusca of North Amer- ica by 403 — I.C., cited 343,372,373 White Cloud Peak, Altitude of 246 — Pine shale 266 Whitfield, R. P., cited 269 Whittlesey, C., cited 316, 336, 339, 384 Wirhraan, A., on the microscopic charac- ters of the Menomince Hurunian 167 Williams, J. S., cited 333 — , Prof. II. S., cited -. 3:>9 — , Pro I'. , aid rendered by 371 Wilson, G. II., Services performed by 243 Wine-hell, A. , cited .' . 326, 329, 334 — X.IT., (ited 330, 332, 3:»3, 33(5, 383 — , referred to. 118, 123, 126, 158, 161, 164, 169, 171 Wings of Hcsperornis -r>9 Ichthyomis 75 Wisconsin geological survey 93 — River Valley, Crystalline schists of 171 Woodpecker's Peak, Altitude of 246 , Devonian of '-'<;."> WoiKter, Prof. L. C., cited 3'J3, 3'A :; 10 Work of chief geologic assistants \v Wright, G. F., cited 302, 341 , 346, 3 17, 380 Zaphrentis (sp.?) '-'70 Zircon in augite-andesito 278 — rhyolito 279 Zirkel, Prof. Ferdinand, cited 285 Zonites priscua 453 RETURN EARTH SCIENCES LIBRARY TO— ^ 230 Earth Sciences Bldg. 642-2997 ALL BOOKS MAY BE RECALLED AFTER 7 DAYS Books needed for class reserve are subject to immediate recall DUE AS STAMPED BELOW UNIVERSITY OF CALIFORNIA, BERKELEY FORM NO. DD8, 7m, 12/80 BERKELEY, CA 94720 6foratf