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ENGINEER DEPARTMENT, UNITED STATES ARMY.
REPORT
GEOGRAPHICAL AND GEOLOGICAL
EXPLORATIONS AND SURVEYS
WEST OF THE ONE HUNDREDTH MERIDIAN,
FIRST LIEUT. GEO. M. WHEELER,
CORPS OF ENGINEERS, U. 8S. ARMY, UNDER THE DIRECTION OF
BRIG. GEN. A. A. HUMPHREYS,
CHIEF OF ENGINEERS, U. S. ARMY.
PUBLISHED BY AUTHORITY OF HON. WM. W. BELKNAP, SECRETARY OF WAR,
IN ACCORDANCE WITH ACTS OF CONGRESS OF JUNE 33, 1874, AND FEBRUARY 15, 1875.
IN SIX VOLUMES, ACCOMPANIED BY ONE TOPOGRAPHICAL AND ONIi GEOLOGICAL ATLAS,
Avan mele VOL. IV.—PALEONTOLOGY.
WASHINGTON: j GOVERNMENT PRINTING OFFICE. 1875.
‘ TABLE OF CONTENTS. A EA: | ee : : Page. CiAPTER I, GENERAL OBSERVATIONS UPON THE COLLECTIONS, AND THE PERIOD THEY REPRESENT... 5 II. CLASSIFICATION BpotOn DOURe DOS rAcOlsous aaa mere e SESE ESS SSS ee tie cnt awe eee wees 21 _ III. Fossits OF THE PRIMORDIAL PERIOD..---. ---- Shs Ag As Ape SE ener pe 32 IVASHOSSIES| OMMTHE) CANADIAN/ PERIOD sco see)eciee ose seer eae aise cesses eel eeeeee eee cine 50 YV. FOSSILS OF THE TRENTON PERIOD.....- Saree aie eo eee eee relaiae eee eine missin chee cin ences 62 VI. FossiLs Or THE SUBCARBONIFEROUS PERIOD..---. ..---. 2-200 ee eee eee cree eens 79 VII. Fossits OF THE CARBONIFEROUS PERIOD ...--. --.. -- 222+ eee eee eee eee e ee cee tee eee 96 VIll. HOSSILSOlU THE, J URASSICRPERIODseeeciieeeeciocciocisiseciceee eaiceer ccen o-tene cere ace ae 162 r DPX SPHOSSIES OM THE) CRETACEOUS PERIODse seiseeeecicne ecceeccece ceeceo cece scceece cre eee 169 Ky HOSSIcsiOr THE TERTIARY, PERIOD)... ..2ce+ one cee oes ese cess eo. ses + alefcieislestaeteseince 206
LIST OF PLATES.
Je ven Jay OR) dey
PuLatEe I.—Primordial period. PLATE XI1.—Carboniferous period. I].—Primordial period. — XIII.—Jurassie period. 1]1.—Canadian period. XIV.—Cretaceous period. 1V.—Trenton period. XV.—Cretaceous period. V.—Subearboniferous period. XVI.—Cretaceous period. VI.—Carboniferous period. XVII.—Cretaceous period. VII.—Carboniferous period. XVIII.—Cretaceous period. VILI.—Carboniferous period. XIX.—Cretaceous period. JX.—Carboniferous period. XX.—Cretaceous period. X.—Carboniferous period. | XXL—Tertiary and Tertiary ? XI.—Carboniferous period.
Umirep Srares Encrynrr Orrice, GEOGRAPHICAL EXPLORATIONS AND SURVEYS West or THE ONE HUNDREDTH MeErtpran, Washington, D. C., December 15, 1875.
Genera: I have the honor to submit herewith a report, in two parts, upon the paleontological results arising from the collections and examina- tions made during the years 1871, 1872, 1873, 1874, and 1875, in connec- tion with geographical explorations and surveys west of the one hundredth meridian, for publication as Volume IV of the reports authorized by Acts of Congress approved June 23, 1874, and February 15, 1875.
Part I is by Dr. C. A. White, on the collection of invertebrate fossils, numbering one hundred and seventy-eight distinct species, of which fifty- four are new to science.
A preliminary report, with descriptions of new species, by the same author, was, with your sanction, published in December, 1874, the sub- stance of which is embodied in the present volume.
The attainments and the experience of Dr. White in this branch of science are a guarantee that his work has been well done.
Part II is comprised of a similar treatment of the vertebrate fossil col- lections, by Prof. E. D Cope, who has given to this subject years of study. Professor Cope was connected with the expedition during the season of 1874, in which he made collections himself, and, in addition, was enabled to prosecute geological researches. A portion of his results were published in preliminary form in a ‘‘Report upon the Vertebrate Fossils discovered in New Mexico, with description of new Species,” November 28, 1874; and a “Systematic Catalogue of the Vertebrata of the Eocene of New Mexico, collected in 1874,” April 17, 1875. His geological deductions appear in my annual report, Appendix LL, Annual Report of the Chief of Engineers, 1875
Several members of the expedition not engaged upon paleontological work have made collections of interesting specimens, evincing a hearty
co-operation in this as well as other allied branches of the survey. M1
ee LETTER OF TRANSMITTAL.
The whole number of specimens have become the property. of the War Department, and will be carefully preserved.
The plates illustrating the invertebrate fossils were drawn by Mrs. H. M. Martin, of Albany, N. Y., and C. K. Worthen, of Warsaw, Ill, and engraved and printed by Julius Bien, of New York City. The vertebrate fossil plates have been prepared from the natural objects, engraved and printed by Messrs. Thomas Sinclair & Son, of Philadelphia.
A merited recognition is hereby tendered to all these who have con- tributed to the results as shown by this report.
Very respectfully, your obedient servant, Gro. M. WurEeEter, Lieutenant of Engineers, in charge. Brig. Gen. A. A. Humprreys, Chief of Engineers, United States Army.
de) vedas JN bs
REPORT UPON
THE INVERTEBRATE FOSSILS COLLECTED IN PORTIONS OF NEVADA, UTAH, COLORADO, NEW MEXICO, AND ARIZONA, BY PARTIES OF THE EXPEDITIONS OF 1871, 1872, 1873, AND 1874.
BY
4
CHARLES A. WHITH, M.D. ¥¢;
———— COMPRISING
CuarTer I.—GENERAL OBSERVATIONS UPON THE COLLECTIONS AND THE PERIODS THEY REPRESENT.
II.-—CLASSIFICATION. III—FOSSILS OF THE PRIMORDIAL PERIOD. IV.—FOSSILS OF THE CANADIAN PERIOD. V.—FOSSILS OF THE TRENTON PERIOD. VI.—FOSSILS OF THE SUBCARBONIFEROUS PERIOD.
VII—FOSSILS OF THE CARBONIFEROUS PERIOD.
VIII.—VOSSILS OF THE JURASSIC PERIOD. IX.—FOSSILS OF THE CRETACEOUS PERIOD. X.—FOSSILS OF THE TERTIARY PERIOD.
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LETTER OF TRANSMISSION.
Unitep States ENGINEER OFFICE, GEOGRAPHICAL EXPLORATIONS AND SURVEYS West or THE OnE HunpreptH MeripiAn, Washington, D. C., June 10, 1875.
Sir: I have the honor herewith to transmit my final report upon the invertebrate fossils collected by the exploring parties under your command during the years 1871, 1872, and 1873.*
The collections were placed in my handsin July, 1874,* and I at once commenced a critical examination of them, followed by the work of pre- paring the whole for publication; which work I have continued uninterrupt- edly to the present time. A preliminary investigation of these collections showed that quite a large proportion of the species were new to science, and, for the purpose of securing to your expedition due credit for priority of discovery, I wrote out descriptions of the new species then recognized, and sent them to your office, with the request that they be immediately published, for the purpose of securing the object named. This publication was made from the Government Printing-Office in December, 1874, and is the one referred to in the synonymy accompanying a republication of those species in this final report, together with additions and illustrations. Another object of this preliminary publication was the announcement of important geological conclusions from paleontological evidence. Among the most interesting of these may be mentioned the distinct recognition of the fauna of the Canadian period in Nevada and Utah; that of the Trenton period in Utah and New Mexico; and that of the Subcarboniferous period in Arizona, Nevada, and Utah.
Besides the new species described in the preliminary report, a full
* Collections of 1874 have since been placed in my hands for investigation, and the results have
been incorporated into the following report. ;
4 LETTER OF TRANSMISSION.
examination of the collections has shown that a few others are also new. Descriptions of these form a part of the present report, with which they will be published for the first time. The whole number of species recognized in the collections and described or noticed in this report is one hundred and eighty-two, of which fifty species were new.
As I have not been personally engaged in any of the field-explorations, my report is necessarily a paleontological one only, confined to a zodlogical description and classification of the invertebrate fossils, a reference of them to geological periods already well established, and a discussion of the char- acter of the evidence afforded by the fossils upon which such reference is made.
My especial acknowledgments are due to those able paleontologists, Messrs. IF’. B. Meek and R. P. Whitfield, for generous counsel and assistance, and to Prof. Joseph Henry, Secretary of the Smithsonian Institution, for extending to me freely all the facilities possessed by that Institution to aid me in the work.
I am, sir, your obedient servant, C. A. WHITE.
First Lieut. Gro. M. WHEELER,
Corps of Engineers, U. S. Army, In Charge of Geographical Explorations and Surveys West of the One Hundredth Meridian.
GENERAL OBSERVATIONS. 5
CHAPTER IL.
GENERAL OBSERVATIONS UPON THE COLLECTIONS AND THE PERIODS THEY REPRESENT.
The critical investigation of fossils collected in newly-explored regions, distant from those in which the stratigraphical relations of the rocks have been accurately determined, especially if the relative position of the strata of those regions has been obscured by disturbance, it is often difficult and sometimes impracticable to assign each collection to its proper geological horizon. The difficulty is greatly increased to the paleontologist if he must prepare his report before those of the field-geologists are available, or if he has not himself visited the regions in question and obtained by personal observation a knowledge of the strata and their relative positions.
This difficulty has been met in the present instance, so far as any person could do it, by Mr. G. K. Gilbert, geologist of the expedition, by whose patient and clear oral and epistolary explanations I have greatly profited. If the collections were abundant in every case, it would be a comparatively easy task to assign them to their proper horizons; but it is often necessary to make some such assignment of a meager and uncharacteristic collection, or to pass it by in silence. This alternative has been presented to me in some instances by the collections that form the basis of this report; and I have chosen to make some assignment of them in all cases according to the best evidence presented, indicating at the same time such doubts as I have entertained.
The accompanying table of the subdivisions of geological time, which are more or less familiar to American geologists, is introduced here for the purpose of showing at a glance what periods and epochs are represented by the fossils of the collections, as well as the relative positions of the strata from which they were obtained. The names of the periods are those used by Dana in his new Manual of Geology (1874), and will be found to differ slightly from those formerly in use.
6 GENERAL OBSERVATIONS.
Table of the subdivisions of geological time.
AGES. PERIODS. EPOCHS.
|
PLIOCENE. Cenozoic. *TERTIARY. MIOCENE.
EOCENE.
* CRETACEOUS.
Mesozoic. * JURASSIC.
TRIASSIC.
2* PERMIAN.
Upper Coal-Measures.
*CARBONIFEROUS, OR CASIO TERS SOIUSS) (OMS Middle Coal-Measures.
COAL-MEASURES.
Lower Coal-Measures.
Carboniferous. : Chester Limestone.
Saint Louis Limestone.
* SUBCARBONIFEROUS. Keokuk Limestone.
Burlington Limestone.
* Kinderhook Group.
CATSKILL.
CHEMUNG.
Devonian.
HAMILTON.
CORNIFEROUS.
ORISKANY.
LOWER HELDERBERG.
Upper Silurian.
SALINA. NIAGARA. * Cincinnati. * TRENTON. ?* Utica. Trenton. Chazy. Lower Silurian. = = * CANADIAN. * Quebec. Calciferous. * Potsdam. ; * PRIMORDIAL. - Acadian.
ARCH ZAN.
* The presence of the asterisk indicates that the period or epoch, as the case may be, is represented by fossils in the collections.
GENERAL OBSERVATIONS. 7
LOWER SILURIAN.
The Lower Silurian age is represented in these collections by fossils referable to all three of its periods, namely, the Primordial, Canadian, and Trenton.
PRIMORDIAL PERIOD.
The collections contain fossils of the Primordial period that were obtained in Western Utah, Southeastern Nevada, and Western Arizona, all of which are probably referable to the Potsdam epoch of that period. The most conspicuous feature of the fauna of the period, as represented by these collections, consists in the preponderance of the Articulate over all other forms of life, and which is represented by Trilobites alone, with the probable exception of the tracks described on a subsequent page. This apparent preponderance, however, is likely to be greatly modified by future discoy- eries.
The genera of Trilobites which these localities have afforded are Olenellus, Conocoryphe, Agnostus, and Asaphiscus; the latter bemg a new genus, recently proposed by Mr. F. B. Meek, probably allied with the Asaphide, while the others, as well as the geological horizon they are understood to characterize, are well known.
The discovery of two species of Olenellus at Pioche, Nev., is especially important and interesting, since that genus has hitherto been regarded as distinctively characteristic of a well-defined Primordial horizon in America. The interesting nature of the discovery is increased by the fact that, in their general characteristics, these two Nevada species of Olenellus respectively represent two other well-known species of that genus similarly associated in strata of the same period in Vermont and Canada. While all the other strata herein referred to the Primordial period have been so referred almost wholly upon paleontological evidence, the Tonto shale of the Grand Canon of the Colorado River has been referred to that period by the geologists of the expedition largely upon stratigraphical evidence. 'The only indications of life that these last-named strata have afforded to the collections consist of two species of Cruziana, besides the tracks that have just been referred to It is true that the presence of Cruziana in those strata does not prove their
Primordial age; but, as such forms are rarely found in strata of other periods,
8 GENERAL OBSERVATIONS.
they may be regarded as adding considerable weight to the conclusions drawn by the field-geologists from other data. As these plants were the only recognizable species furnished by those strata, holdig as they do so important a stratigraphical position, I have added descriptions of them to the others, although it was originally proposed that this report should be confined to invertebrate fossils alone. The existence of strata of the Primordial period at several localities in the Rocky Mountain region has been heretofore announced by different explorers; but the discoveries made by the Explorations West of the One hundredth Meridian constitute a mate- rial addition to our knowledge of the rocks of that period in the western part of the continent.
CANADIAN PERIOD.
Small collections made at a few localities in the House range, Western Utah, and in the Schell Creek range, Southeastern Nevada, I have referred to the Canadian period. The collections are not only small, but they com- prise in all only twelve species. A part of these, however, are regarded as quite characteristic of the Quebec epoch of that period, to which I have assigned them with very little hesitation. Small as they are, these collec- tions present a much greater zodlogical diversity than those of the Primor- dial period do, and there is not among them that preponderance of one zoological type over the others that has been mentioned as occurring among the collections of Primordial fossils, which consist very largely of Trilobites. The subkingdoms Protozoa, Radiata, Mollusca, and Articulata are all rep- resented among the fossils referred to the Canadian period; the species and higher groups to which they belong being compactly shown in the syste- matic table ona following page. Among the more important of the char- acteristic forms of this period contained in the collections, the species of Phyllograptus deserves especial notice as being the first species of the genus yet discovered in the Rocky Mountain region, and also because the genus is regarded as peculiarly characteristic of the Quebec epoch. The discovery of strata of this period in Nevada and Utah is important from the fact that, with the exception of Professor Bradley’s discovery in Idaho, their existence throughout the great Rocky Mountain region was heretofore unknown.
GENERAL OBSERVATIONS. 9
The discovery derives additional interest also from the fact that the period as such, and as distinct from the Primordial on the one hand and the Trenton on the other, has not, until lately, been fully recognized.
So far as known to me, neither the Calciferous nor Chazy formation of this period has been recognized in connection with the Quebec strata referred to, nor indeed anywhere in the Rocky Mountain region. It is too early to say or suggest what bearing this fact may have upon the opinion under- stood to be entertained by the Canadian geologists that the Quebec strata are deep-sea representatives of those of the Calciferous and Chazy forma- tions.
TRENTON PERIOD. ©
The localities at which fossils belonging unquestionably to the Trenton period have been collected are Silver City and Upper Mimbres Mining Camp, N. Mex. A few other species have been collected at other localities in Arizona and Nevada, which localities are more specifically designated in connection with descriptions of the species on following pages. These species [have also referred to the Trenton period, but the intrinsic evidence they afford as to their stratigraphical position is not so entirely satisfactory as that presented by the collections from the two first-named localities. Besides all these, four species of Graptolites were collected from partially metamorphosed shale near Belmont, Nev. No other fossils were found associated with the Graptolites that might aid in indicating their exact strat- igraphical position; but I have referred them provisionally to the same period with those already mentioned.
As regards the epochs of the Trenton period to which the fossils of these localities respectively belong, those from Silver City and Upper Mimbres Mining Camp are referred without hesitation to the Cincinnati epoch. . This is done not only because of the general similarity of faunal characteristics, but also because of the identification of four species from the strata there that are characteristic ones of the strata of that epoch at the typical localities. The four species referred to are Favistella stellata Hall, Strophomena filitexta Hall, Orthis biforata Schlotheim (var. lynx), and O. occidentalis Hall.
10 GENERAL OBSERVATIONS.
Associated with these, there are some other species that, if not identi- cal with associates of those species just named elsewhere, are very closely allied to them. Indeed, it is worthy of remark that there is so large a pro- portion of the species here referred to the Trenton period that are very closely allied to well-known species, and yet present such minor differences from typical forms, that I have felt obliged to append an interrogation-point to the names of the species I have referred them to. The Graptolites prob- ably belong to the Utica epoch of the Trenton period, and I have made that provisional assignment of them.
Two of the Nevada species, Graptolithus ramulus White and G.. hypni- formis White are allied to two species, G. ramosus Hall and G. Whitfieldi Halj, that are found in the shales at Norman’s Kill near Albany, N. Y., the exact stratigraphical position of which shales has hitherto been in doubt. One, G. pristis Hall? (not Hisinger), is apparently identical with a species from the Utica slate of New York; the other Nevada species is probably identical with G. quadrimucronatus Hall, the type-specimens of which were obtained from strata of the Utica epoch near Lake Saint John in Canada. While the exact stratigraphical position of the shales at Norman’s Kill has not yet been demonstrated, the strata referred to at Lake Saint John are, upon published evidence, referred without hesitation to the Utica epoch. I am not aware that any species found in strata of that epoch at the last- named or at any other locality are identical with any found at Norman’s Kill; but the relations of our Nevada species of Graptolites are very close with some of those found at both of the eastern localities just mentioned. It does not seem improbable, therefore, that this far western locality may be found to furnish important evidence of the equivalency of the strata at Norman’s Kill with the Utica slate. (See note at end of chapter.)
It is not unfrequently the case that Graptolites constitute the only organic remains found in shales of Silurian age. This is doubtless due to the fact that the physical conditions of the sea, in which that kind of sedi- mentary material which now constitutes the shale was deposited, were favor- able to the existence of such forms of life, and at the same time made the habitat an uncongenial one for other forms. The fact, therefore, that the
Belmont shales have furnished almost no other fossils besides Graptolites is
GENERAL OBSERVATIONS. 11
not remarkable; but it is worthy of remark that the collections from Silver City and Upper Mimbres Mining Camp, with the exception of one Conchi- fer, contain only arthropomatous Brachiopods and corals; the molluscan classes Polyzoa, Gusteropoda, and Cephalopoda, and the whole subkingdom Articulata, being unrepresented. The corals belong to families common in strata of that age, namely, Favositide, Cyathophyllide, and Thecide ; but the Brachiopods, with the exception of one, Rhynchonella, all belong to the family Strophomenide.
Peculiar interest attaches to this discovery of strata of the Trenton period in New Mexico, Nevada, and Arizona, as well as to the discoveries concerning the other Lower Silurian periods, from the fact that so little has hitherto been known of their existence in that part of North America. Indeed, with the exception of the discovery of strata of this period by Jenney in Western Texas, and that of a similar one by Dr. G. G. Shumard in Southern New Mexico, I am not aware that the existence of any besides those here announced has been recognized in that part of the continent.
UPPER SILURIAN.
The collections contain no fossils of Upper Silurian age, nor has the existence of any strata of that age in the region over which the explorations have extended been ascertained, as far as I am aware.
DEVONIAN.
Among the collections are a few fossils, the locality for which is given as “between San Antonio and Silver Peak, Nevada.”
All of them are too imperfect for satisfactory specific description ; but, judging from their general characters, they seem to be of Devonian age. The genera, so far as they are recognizable, are Favosites, Acervularia?, and Zaphrentis. There are also some fragments, probably of Atrypa reticularis, and part of an undetermined Trilobite.
CARBONIFEROUS.
Nearly half of all the species contained in the collections are referable to the Carboniferous age, mainly to its middle period Among them are some very characteristic fossils of the Subcarboniferous period; but the
Permian has only doubtful representation.
12 GENERAL OBSERVATIONS.
SUBCARBONIFEROUS PERIOD.
The physical conditions that prevailed during the Subcarboniferous period over what is now the North American continent were quite various; but the rocks of the period possess general distinctive characters in their fossil fauna, by means of which they may be separated with little difficulty from those of the next succeeding period. It is in the valley of the Missis- sippi that they are most characteristically developed, and where five distinct formations, marking as many epochs, are found. The names of these for- mations in the ascending order are the Kinderhook group, Burlington lime- stone, Keokuk limestone, Saint Louis limestone, and Chester limestone. Each formation has its own characteristic fauna; but through all of them a few species are continuous, even into the strata of the next period, the Car- boniterous. Taking these Subcarboniferous formations together as the stand- ard for the group, it has been found more or less difficult to recognize their respective equivalents among the rocks of the same period, either eastward or southward from that region, or, at best, the order of succession is nowhere so well shown as it is in the region referred to. Inthe Rocky Mountain region, it has been found that there is, at many localities, a greater or less mingling of Subcarboniferous with Carboniferous types; but at quite a number of localities, collections have been made that are regarded as distinctively Sub- carboniferous. Only a very few of these collections, however, exhibit a fauna clearly referable to any particular one of the formations of the period that have just been named. Perhaps the most remarkable of the collections of this character is the one made by Professor Bradley in Idaho, the fossils of which Mr. Meek has found to be strikingly characteristic of the Saint Louis limestone as developed in some parts of Indiana.
The collections of the expedition contain fossils from only three locali- ties that I have definitely referred to the Subcarboniferous period. These localities are Mountain Spring, Old Mormon road, Nevada; Ewell’s Spring, Arizona (upper horizon); and a place below Ophir City, Utah. The collec- tion made at the first-named locality is the most characteristic and important one of all, and is referred to the horizon of the Kinderhook formation, to which horizon it is not improbable the cthers also belong. As the recogni- tion of distinct epochs of the Subcarboniferous period in the Rocky Mountain
GENERAL OBSERVATIONS. ik
region is a matter of considerable importance, I give the following detailed statement of the relations of these fossils to the typical fauna of the period, and especially to that of the epoch to which I have referred them. It is well known that in America several species of fossils are known to range through all the formations of the Subcarboniferous into those of the Car- boniferous period, especially into the limestones of the latter. The discovery of any of these species alone in any given strata would not, therefore, enable us to refer the strata containing them to one of these periods rather than the other. On the other hand, certain genera occur in strata of each one of these periods that are not known to occur in the other, in which latter case the generic character becomes of greater value than the specific in the former. It is upon evidence of the latter kind that I have referred the fossils of the three localities named to the Subcarboniferous period.
The following list contains the names of the genera represented in the collections from those localities :—
Favosites. Syringopora.
Granatocrinus. Zaphrentis.
Platycrinus. Productus.
Actinocrinus. Hemipronites.
Strophomena. Orthis.
Spirifer (Syringothyris type). — Spiragera.
Conocardium. Spirifer ( Trigonotreta type). Terebratula (Dielasma). Enomphatus.
Those genera of the left-hand column are not known to occur in strata of later date than the Subcarboniferous, while those of the right-hand column are known to range both above and below it. The generic value of the latter genera in this case is only to add weight to the evidence afforded by the others, which is of itself, however, very decisive. Here are seven genera, that are known to occur in Subcarboniferous strata elsewhere, but are known in no strata of later date; and as they are found at the localities named associated with types peculiar to the Carboniferous age, the propriety of referring the species which represent those genera in the collections to the Subcarboniferous period seems unquestionable.
14 GENERAL OBSERVATIONS.
Although I entertain no doubt of the Subcarboniferous age of the fossils from the locality below Ophir City and the one at Ewell’s Spring (upper horizon), I am not able to assign them definitely to either of the epochs of that period that are represented by the formations before named in the Mississippi Valley and elsewhere to the eastward of that region. The case is far different, however, with the collection from the Mountain Spring locality, which I refer without hesitation to the Kinderhook group.
This reference is made in consequence of the identification of no less than five of the species known to exist in rocks of that epoch in the States of the great valley and eastward. The following is a list of those species, together with the localities that furnished either the types or authentic speci-
mens :—
Strophomena rhomboidalis Wilckins—Kinderhook group, Burlington, Towa.
Spirifer (Martinia) peculiaris Shumard.—Kinderhook group, Missouri and Iowa.
Spirifer centronata Winchell—-Waverly sandstone, Cuyahoga Falls, Ohio.
Spirifer (Syringothyris) eatenuatus Hall—Kinderhook group, Iowa and Missouri.
Terebratula (Dielasma) Burlingtonensis—Ilinderhook group, Burlington, lowa.
Associated with these and other species at Mountain Spring, there is a small Productus that I have identified with P. parvus Meek and Worthen, the type-specimens of which were obtained from the Chester limestone of Illinois. This might seem to throw some doubt upon the proper identi- fication of the strata at Mountain Spring with the Kinderhook group, were it not for the fact that other species of Productus are known to range through the whole Carboniferous series. Indeed, more species of this genus are known to have this great range than of all other genera of invertebrates put together.
It is a well-known fact that crinoidal life was eminently characteristic of the Subcarboniferous period ; but, in the Mississippi Valley, it is the Bur-
GENERAL OBSERVATIONS. 15
lington and Keokuk limestones that are more especially characterizedgby a great preponderance of these forms. Although some crinoidal remains exist in those Subcarboniferous strata that have been discovered in the Rocky Mountain region, in none of them have they been found in so great profu- sion as they exist in the two formations in the Mississippi Valley that have just been named. In this respect, the collections from those western locali- ties accord more nearly in faunal characteristics with the other three forma- tions of the Mississippi Valley series.
It could not be expected that collections of Subcarboniferous fossils so meager as those made by the expedition are should afford any very com- plete indication of the relative prevalence in that region of the different forms of marine life of the period ; but it may be well to note that they con- tain no remains of fishes, no Articulates, and no Cephalopods, arthropoma- tous Brachiopods being the prevailing forms. Such deficiencies as those noticed are, however, not uncommon in much larger collections from typical Subcarboniferous strata.
CARBONIFEROUS PERIOD.
The accession, in the Carboniferous age, of the conditions necessary to the formation of coal was not simultaneous in all those parts of North America over which deposits of that age were made; nor were these con- ditions sooner or later co-extensive with all parts of the area in which those deposits exist, not even with those of the Carboniferous, or so-called Coal- Measure, period. It is also known that these conditions, even during the period of their greatest prevalence, occasionally ceased by shifting elsewhere, and were resumed again; alternating thus with conditions similar to those that prevailed at the beginning of the age, before the first coal-deposits were formed. In what are now portions of Pennsylvania, Virginia, Kentucky, and Indiana, these coal-making conditions began before the close of the Subcarboniterous period. Although their prevalence became general during the deposition, in the eastern half of North America, of the strata of the first and second epochs of the Carboniferous period, especially the first, the strata of the third epoch of the last-named period are usually as destitute of coal as those of the Subcarboniferous period are.
Indeed, the conditions that prevailed during the Upper Coal-Measure
16 GENERAL OBSERVATIONS.
epoch were essentially a repetition of those which prevailed during the Subcarboniferous period. Bearing this in mind, it is easy to understand that those species which are found in both Subcarboniferous and Carbonif- erous strata may have reached the latter position merely by continuous geographical distribution during the progress of the two periods. Geolo- gists generally divide the strata of the Carboniferous period, in the eastern part of North America, into Upper and Lower Coal-Measures; but, in Iowa and Missouri, they are more or less naturally divided into three formations, as betore indicated. Westward from those States, the strata of the Carbo- niferous period have not been separated into corresponding epochal divis- ions, and are perhaps not capable of such separation. In the Rocky Mountain region, the strata of this period are widely distributed, and attain a very great thickness compared with that of those in the Mississippi Valley. Those far western Carboniferous strata probably represent in the aggregate the whole Carboniferous period, but in their general lithological and pale- ontological characters they are all much more nearly like the strata of the Upper Coal-Measures as developed in Iowa, Missouri, and Nebraska than they are like the Middle and Lower Coal-Measures. So far as known to me, no considerable deposit of coal has been found in any strata of the Carboniferous age in the Rocky Mountain region. The accession and cessation of the physical conditions necessarily attendant upon the forma- tion of coal seem to have constituted the principal means of marking, in the accumulating strata, the epochal divisions of the period in Eastern North America. ‘Those conditions of coal-making not having prevailed in the Far West, and, so far as known, the physical changes that occurred there during the period not being coincident with those farther eastward, its epochs were not there marked off in the same manner.
The collections contain a greater number of species from strata of this period than from those of any other; and they were also found more abundant than those of any one of the older periods that have just been noticed.
Of the sixty-two species that have been described or noticed in this report and assigned to this period, one is a Rhizopod ; six, Actinozoa; two, Echinodermata ; three, Polyzoa ; twenty-nine, arthropomatous Brachiopoda ;
GENERAL OBSERVATIONS. 17
ten, monomyarian Conchifera; two, dimyarian Conchifera; six, Gaster- opoda; and three, Cephalopoda. The two species of Echinodermata do not, however, correctly represent the relative prevalence of that class, because the geologists of the expedition report the presence of scattered joints of Crinoids at almost all the localities, but which, being of little value for classification, were not collected. Of these sixty-two species, thirty- nine are more or less frequently met with in strata of the Carboniferous period in the States bordering upon the Mississippi River.
Although the faunal characteristics of the period are so clearly and fully shown in the collections, the flora of the period, so abundant in the States eastward, has very slight representation among them. Indeed, the collection contains only a single specimen each of Sigillaria and Neuropteris ; the former from White Pine, Nev., and the latter from Cedar Creek, Maricopa County, Ariz.
PERMIAN PERIOD.
The collections contain no fossils that I have definitely referred to the Permian period. A few imperfect specimens were collected from a porous, apparently magnesian, limestone, near Jacob’s Pool, Arizona, which is prob- ably at the very summit of the Carboniferous series. One of the species only was satisfactorily recognized, and that is referred to Bakevellia parva Meek and Hayden. The collections also contain specimens apparently identical with that species from strata near Camp Wingate, N. Mex. The strata are probably equivalent at the two localities.
MESOZOIC. TRIASSIC PERIOD.
So far as can be determined, none of the invertebrate fossils contained in the collections are properly referable to the Triassic period.
JURASSIC PERIOD.
The collections contain only eight species in all that I have referred to the Jurassic period. All of these were nowhere found associated together in the same strata; consequently the fauna of the period was nowhere found
2F
18 GENERAL OBSERVATIONS.
fully represented. The collections were made at somewhat widely-separated localities in Nevada and Utah. I have referred the species to the Jurassic period without hesitation in all cases where they were identical, or associated with species hitherto described by Mr. Meek, or Meek and Hayden, and referred by them to that period. With the exception of one crinoidal species,
the fauna of the collections is wholly molluscan. : CRETACEOUS PERIOD.
Next to the Carboniferous period, the Cretaceous is represented in the collections by the greatest number of species. These were obtained at various points in New Mexico, Utah, and Colorado. For want of available data, no attempt has been made to refer them respectively to the different sub- divisions of the Cretaceous group that have been recognized in Western North America by various geologists ; but they are all regarded as clearly referable to the-Cretaceous period. Although individuals of most of the species are numerous, it is interesting to observe the restrictions of zodlogical diversity which the collections, consisting of thirty-two species, present. For _example, the Protozoa and Radiata are entirely wanting ; the Articulata rep- resented by a single species of Serpula only; and all the remainder are Mol- lusca. Of these, the Molluscoidea are represented by a single species of Lingula; thirteen species are monomyarian Conchifera ; five, dimyarian Conchifera ; nine, Gasteropoda; and four, Cephalopoda.
CENOZOIC. TERTIARY PERIOD.
The collections contain fifteen species from strata at different localities in Utah that I have assigned to the Tertiary period, all of which, except one species of Cypris, are either fresh-water or land mollusks, mostly the former. Three species are Conchifera, and of the remaining eleven species five are pulmonate Gasteropods, an order that is not represented in any of the other collections.
If I were left to rely upon the zodlogical types alone which the fossils of this small collection present, I should have no hesitation in referring them
GENERAL OBSERVATIONS. 19
all to the Tertiary period. In view of the fact, however, that strata at some localities in that Territory, containing a fauna as suggestive of the Tertiary period as these fossils are, have been found to underlie strata containing true Cretaceous types, I prefer at present to regard the reference of at least the greater part of them to the Tertiary period as provisional.
Notr.—After writing the foregoing, I learned that my friend, Mr. R. P. Whitfield, the well-known paleontologist, had been making some special studies of the Graptolite slates of Norman’s Kill, and wrote to ask his opinion upon the subject, to which inquiry I have received the following reply. I insert it here because of its important bearing upon the question of the age of the shales at Bel- mont, Nev. :—
“ALBANY, N. Y., February 18, 1875.
“DEAR Sir: Your inquiry in regard to the geological age of the Graptolite slates of Norman’s Kill near Albany, N. Y., involves a question of considerable complexity, and is one to which I have given much thought and labor during several years past. The rocks in that vicinity are so altered and dis- turbed that their relative position is not easily determined from stratigraphical evidence. I have sought diligently at all points for fossil remains, but with only limited success thus far, except as to Graptolites. From the evidence furnished by these fossils, I have reached the conclusion that the Graptolite-bearing layers there are of the age of the Utica slate, the following being asummary of the facts I have observed :—
“T have found the following species common to both the Graptolite layers at Norman’s Kill and those of the Utica slate formation at the mouth of Oxtungo Creek near Fort Plain, N. Y.:—Graptolithus (Monograptus) serratulus Hall; G. (Diplograptus) pristis Hall (not Hisinger); G. (Climacograptus) bicornis Hall; and G. (Dicranograptus) ramosus Hall.
“At Ballston, N. Y., G. bicornis Hallis very abundant in the Utica slate; and at Barker’s Falls, near Sandy Hill, N. Y., G. pristis is equally abundant in the same formation. On the island of Orleans in the Saint Lawrence River, and in the valley of the Saint Anne River in Canada, three of the forenamed species are known to occur, viz, G. pristis, G. ramosus, and G. bicornis Hall, in beds known to be of the age. of the Utica slate (see Geological Report of Canada, 1863, page 200). I think that G. (Dicranograptus) sextans Hall also occurs in the same layers with the above-mentioned species, but I will not be positive,
“Tam confident that if-all these localities were as thoroughly examined as that at Norman’s Kill has been, many more species would be found to be common to two or more of them; but the evidence already given is quite sufficient to warrant the conclusion that the slates of the several localities named
_are of the same geological age, especially when we consider the fact that Graptolites have a very limited geological range. Although only four species are positively known to be common to two or more of the localities named, some of them are found at widely-separated characteristic localities of the Utica slate, which shows the great geographical range of the species. None of the Norman’s Kill species have been recognized in any other formation than the Utica slate, which, while it demonstrates their equivalency of geological age, also shows the limited geological range of this family of fossils.
“Besides the foregoing evidence, the following facts are worthy of consideration in this connec- tion. The lithological features of the Norman’s Kill Graptolite beds are peculiar, quite different from the other beds near by, easily recognized at distant localities, and evidently as near like the Utica slate as a metamorphic slate can be like an unaltered one. Ata locality of these slates near Cohoes, I found specimens of G. pristis undistinguishable from Norman’s Kill specimens, and in another layer not many feet from the first, but of somewhat different lithological characters, I collected Orthis testudinaria, Leptana sericea, Bellerophon bilobatus, and Trinucleus concentricus, also an Orthoccras and several small lamellibranchiate shells. In another layer, a short distance from the first and in a direction opposite the second, but nearly in the strike of the beds, I found specimens of an Orthis closely like, if not identical with, O. subquadrata Hall. On the opposite side of the Hudson River, near the base of the hills just above aud back from Lansingburgh, a mile or more from the river, I obtained G. pristis and G. furcatus, another Norman’s Kill species. Just south of Troy, in the shaly partings between layers of metamorphic limestone, I have found a species of Graptolite in great abundance undistinguishable from G. amplexicaule Hall, from the Trenton limestone of Herkimer County, New York. The same species was also fonnd abundantly in the yard of the arsenal at Watervliet by Capt. C. E. Dutton, U.S.A. At Norman's Kiil,
dw sonny worn
“SOY PUD SAUOJSOULT UOPUALLT;
Graptolite - , 77 jlo Be u
Hadsow Riv.
GENERAL OBSERVATIONS.
only a few hundred yards from the Graptolite beds, in arenaceous layers, I found a species of Graptolite closely resembling and prob- ably identical with one figured in vol. i, Paleontology of New York, plate 72, fig. 1 a, found at Turin, Lewis County, N. Y., in the Hudson River group, and at that time identified with G. pristis, but probably distinct.
“From the foregoing facts, I infer that the slates below Troy and in the arsenal-yard, together with the associated metamorphic lime- stones, are the equivalents of the Trenton limestone; and that those at Norman’s Kill, which bear the Lewis County species of Grapto- lites, are probably a continuation of the arenaceous limestones and shales seen in the ravines and railroad cuttings in the town of Knox, Albany County, and of those layers quarried near Schenectady, N. Y., known as the ‘bluestone’; and also that they are the equivalents of the Lorraine shales of Central and North Central New York. All the physical peculiarities of the Hudson River beds, as seen at the locali- ties just mentioned, are so exactly repeated in the disturbed and newly vertical layers within a few hundted yards of the Graptolite beds, that it is difficult to believe they are not geologically identi- eal. One peculiar feature, often noticed on the rocks at Schenectady and elsewhere, is very common at Norman’s Kill: it is the appearance as of flowing mud scddenly fixed and hardened on the harder layers; the depressions between the folds and wrinkles being filled with fine mud-shale partings, upon which the layers separate with clean sur- faces.
“The beds at Norman’s Isill are so much disturbed and contorted that it is impossible to trace a given layer to any considerable dis- tance. There are also many slight faults of a few inches, or some- times several feet ; but I have seen no evidence of any greater one in the vicinity, neither do I think it probable there is one, or that a proper explanation of the condition of the strata makes it necessary to infer that one exists there. The position of the beds there, and the appearance of the Utica slate and of Trenton limestone in the vicinity, can be more reasonably explained by assuming the presence of a series of folds or overlappings, increasing in strength from the vicinity of the nearly horizontal beds of the Hudson River group only afew miles westward from the river, which thus bring up these lower formations, as shown in the accompanying ideal section. You will find this section similar to one given by one of the best and most reliable geologists on page 234, Geological Report of Canada, 1863, for these same formations at another locality.
“Very truly, yours, “RR. P. WHITFIELD.
“Dr. C. A. WHITE.”
CLASSIFICATION. itt
CHP AG Mtoe sili
CLASSIFICATION.
If fossils were to be regarded as merely medals or tokens of geological formations, to serve the purpose only of distinguishing the latter from each other, a knowledge of their biological relations among themselves and to existing forms would be unnecessary, and their classification, beyond the application of convenient names, a useless and cumbersome labor. As our knowledge of paleontology increases, however, the great value and impor- tance which the higher groups possess in the solution of geological problems, not to mention their bearing upon purely biological subjects, are more and more recognized. The custom that has been prevalent of recording only the generic and specific names of the fossils described has long been felt by the best paleontologists to be insufficient to give full expression to the significance they possess. Consequently, a more or less complete zodlogical grouping of them has of late become more common. ‘There seems to be no rational ground between a full classification on the one hand and the mere mention of the name of each species in connection with its description on the other. I have, therefore, compiled a full zodlogical classification of the collections that form the basis of this report. In doing so, I have generally adopted the system used by the best specialists in each department; and their use here is merely one of present convenience, and not necessarily an expression of full approval. For example, an obvious reason for the adoption of Dr. Gill’s arrangement of the families of Mollusca may be found in the fact that the collections by law go to the Smithsonian Institution, where that arrange- ment has been adopted for its cabinet. This should not be understood as an expression of my own views as to the systematic position of the Brachio- poda,any more than the use of Edwards and Haime’s classification of corals implies an approval of the assignment of Chetetes and related corals to the Zoantharia, &e.
Following is a tabular view of the classification I have adopted for the collections, repeated for each of the geological periods they represent.
CLASSIFICATION.
22
“VISNSIA
“spay ITJPMOFT snppousyo APPIN NASq LED snj[sue[O *YooTY Mopooy Ay suosrydesy ‘yoo WSuLyy aydAro0v0u0g, OUUAA SNIOLYSAOJUL snysousy
capes te’ OB PIXOP CAL Cl ta |esmate pencnn grea chao a wba | riateiten soe OP esa tenis | line ey esas int oe coed aa epiydesy May t epee ate. crt ac panes Segre gh O D fancind | eerie ee = meee SS 1c +> xprydd1os0u0g Bee ree gerte ie? whats oo 7 | a anes sect © DD epee | saci Sa ienede, SAS nS. S.8 Ste heweiet xprjsousy ae pe oarscabe et | [oo cores es BIC OTITT, [i tk ae Bee
“VIVTNOILUY
(é) TRH sierprownid say poAy
toot o---0g
+|-2 2222-2 -0q
teres sso
Toss = BaOvISNAD
erie >> wepryy[oAFT Rarer ae tn eon a mg "o>" = VyLULOSOdIYL TL === ---epodolelg
“van vISNIOTY
AINA SHynuued syvusty, AU MA CNPISGNS 2 vjo1}OINV
Eaoo0oo00 Pop rictc [rvs sree secece secs |eeeeee ees op cece fese eee cree coos
Ss amuamaerie OC DTUTOS TG] lieraaee i = terials 7-7" eyeutodokT Sete ea et
~~ >-epodosajseyy
testes eso “>> -vpodorpovrg
*vapromsnppoyy *VOSATIOW
‘VITVWINV
UY VOYSNI vuLIznAD “OPI AA TuOSsivuury] vuriznid
ag06 DESO EdHOSN culos ou GoGo Sag aHo 66d0|\aaop denen setts cece [eee cece ee erence |ee eee ee ag
cece ne coc wns conn nel oo eos wee eee eee Seeccs clemace cose =|| wimlntelieieleeimletulncal=|= i= s277> suaSoy[eyyy
*satoads puv viouar
“Aprure y *lap1oqng “Tapio *ssvpoqug
=
“VINVOOLIAND “‘WLINVId ‘Goldadd IVIGYOWId
HOV NVIGOTIS FAMOT
‘spssof “ayjo pun aynaqnacaur ayy fo ajqn, oywuajshg
*SSU[D
23
CLASSIFICATION.
‘AIT AA SNPNvoAsey ¢ snpeydasoypas1qq “AUYAA SNAnuutajaq sidsvpesapy ‘ONY AA VIAIG vIypssday |-----> aeprurpriddsa |--+7e cece tees eres
ee aes expiydesy ates Tee te
se eceeee ss op rere
> ANGRY RAL, | 922909 09 (pTeREAIIEG) ||OSS0 0908b0 BacAd| poooce TeRTa TES)
--0g
tererce senses |eeeee oq
“VLVTNOILAUY
*(€) ——— svi990}1h9 |-- -* epreza90}1h9 |--7 777 77 ‘AUYAA UOTOD svzad0yjIO |°--- Vpyvr0yWO |°-7 77 TT TTT rere ‘AUY AA SNOMODaT[e uoydosrsjjag |- * epyuoydorarjag |- vyeryouvaqourssiq
porsee corset eee] sence og
sss op-c “7 > eyeryouviqeajay, |---> =" °"7- °° 27°-1-> - epodoreydag “+> essopsoprydiyyy > -> +777 s eoa01q |-- -- epodosajsexy
* ‘plan posmpoyy
(2) Su eNeLT SAO AU AA StTLuUHuoZ vuowutoydoajg |--- apruautoydoyg |-- 777-7 crete eee “ONY AA P[NoIpixAd vjamjoxoy |---"--7* eeprumosiqy |-7 777 teeth totes ‘OU AA EMO QuCUL vondury |-------seeprynsury |---- *-7 +s ese sees
crttees top rrectferesrene:
svaplomsnpjojy
“VOSNTIOW
AUYAA WurtoT snjgdvssoypAyq |*7-> -> epyyoidesy
en ere aneng OD maze ie Sia Se pevetebe 7] orscearaias man © GI ie vyeuodomyiy BB ce et maa ae ata | ei oan sae © (AT 2000 050060 @)OOR0n eee e wen e ceeee- SEC OnSDeaap
SOR O00 SATAY. Gg [9229202098 220000 oo boreal LiBLEAtaT
- eprorpAzy |> “222 =° eozoIpATT
“VLVIGVY
W——=
saynovydasayy |-->- +
ssa | amare? TO FUULLULLG TO Ta | acc elcaechacaicde | cleasoaeane DOCLOZITT S|
“VOZOLOY I
‘dOIWad NVIGVNVO
CLASSIFICATION.
24
*yaoTT snostysoay vurojstydeyy *(¢) ———_ varnpryy *(¢) —— sisdoorpoy
7S eepllivwojoMe[q |s= > 452 sees OPses ss so--7* xplainpey {7 -> vwupeqjyydopog piers hoe coeseC DIT AALS | ciecriagmton scree
“pLaa DISNIOTY
OUT AA VOIGINJUISIV vjpouoyouAyY *XUAT “IVA “JOTYIS VILIOJIG SIAC, *(g) ueueg vriaeuIpnysa} SIq}IO
*(e) TH ereqwoud siy3310 ‘TIeLT Stequeptoso sitp}1Q
(2) Aqaamog vaorias vuaydaT TH VyxXo yy vuowoydors
SOSA IOLUOM PING RYT ||PPSFIOSC 2006 GOSoc¢
seceeeesoprccrt|rttee ooa8
coeo coadan op trrrt [ter eee cert eect
sore eteese op teres |eeeeee cere sees eeee
500s D0n05 op*-77- BodadD HOST ODSo060G
seteestop cree [estes COD SA) (E\Cfafeloa{s} OCICS GOc0 FOES
spapiomsmgjopy
“VOSATIOWL
*(¢) ——— synuoiydez
LEED PIE [[93S Clos ACL
*(2) ——— so}ISOAv yy
‘QUIIVET puv sprveapy weq vaodrnonuoyy *(é) [[eHT snjeuosonuttapenb snyytpoydeay (2) eH sustad snyqoyde.g
‘DUY MA stuuszojtuddéy snyyyoydvasy
“OTA, SHTNUVI sno dvay
*soloads puv viouary
== leapr[Aydouyeha loos 22a sa aed aas wpwoyy, [roots eer
sore cece ne Gp rene [enn o ns con cescoceee
RTOS) OY BY LOY GAS Bi patient See tee ae oa aw
tees esess+ op
teteceee ss oprttt: addnswocnano becood
sere eeeses op ceree|reeece crete cece
CORA Hy yy CeReRES), ||P PPCEO OCI OAOOCA
“ATU LT *raproqnsg
seeeeesest ope: --> vssopsoprydiy yy -7-> viavkulo1oja FT
++ op cote [eree 27 0g per eco vow |---* vpodosaysvx)
PRLS ERAT ea aaa =| rts VAIJIYIUOD)
steeeeeees op ttre seeseeeres op ttre: teeeee sees op tree seeeee sees op crt seeeee cert op cree sereeeeess op cette *--> vyeutodoryy
seetee sere eeceee lessees == og eo oe ye:
se [ereeee ess
oe ocala
sere cee t ee etee cs lennon eso
saeeee 9NBO.000080|5090 0000 Sear ag ec tee -- +> epodorprig
BOBONS (a9) FCCC BECOOI CONS Gy) IOS BOQGOONOSS @ya} OSOSE soreee = BIIVYULOZ - BEDE (9s). O& OOOO OAL (68) EAR ORO COG (63) SISOS
soreee ss eprosphHy
rote pees ee eeeeee [os eeeees og
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ere eceere simaeree 9 | oacameee gOO ZOUTION:
oe ea
=o
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BI ta (poe a ae vozoipAyy
‘IOPIO
*ssepoqusg 14 10)
*VLVICVY
‘dOINad NOLNYYL
‘ponuyuoo—AOV NVIGONTIS YAMOT
‘ponuyu0g—sprssof ayjo pun aypagajraaur ayy fo ajqv, aynuajslig
25
CLASSIFICATION,
“IOYIST vorpurféo vurnsn Sema arta oie iia a oaraade | acai ens camo ceeets | ane eem ETO} LLU BLO.
“VOZOLOUG
‘dolddd SNOWHHINODAVO
‘OUTTA. snxnt snpeyduong *(é) umipivoou0;,
‘aPY AA SISUIUOJSuTpANg (eurseyarq) epN}eaqesay,
AausayOoy vuurxeugo vaast1dsg
“OUI AA Lfoonuout vsostuds
*pavumnys sterpnoad (vruyaeyy) zaytudg ‘eH snyenuaj}xe (stkyjosurs4s) aarndg *(2) unary snjqerys raytuidg
‘TPYUAA SNyeuoIUed raytudg
‘SUTIIAA SITeproquioyt vuautoydo.14s ‘UdYIOAA puv Yoo snaied snjonporg
“7 +> epryeyduiony eee DLe a)
“Dd DISINJOTY
do eae | nce vpodoziyyy
s-*+ vuetydopog |-~* vssopsoprydiyy |-----7-> > voa~iq |-- >> epodosaysey
Ge eet ch Sagi Seer ma ce soo> >> BlIvAWIG,
“77> eeplnqyeiqaray, teeteteee op ttt: tetteeeses op rte sertestesrop crt teeeeetees op rte teeeeetest op crt sseees > eepuopuids >>> aepruautoydo1yg => =>" -gepnyonpolg
terete ceceee ere ees|eeeeee eee Op eee: sort essceces eee ecefessees cers ope eeee
tere ctec cece eee ees [eee eee eees ope eeee
eneee===-6p 2 ao=" vooees en 2+ gp sen=s
a Saat Ra TT ee hae eyeurodoryjry
*wapioomsngjopy
“VOSNTTOJN
OUI AA ‘SNOLIA snuTIOOUTOW
*(é) ——— snuno4qvyq
‘OU AA. SNISLIGOJOT snurID0}vULIN
roy AA haarezy vrodosuriss
"PPYUYAA PUv IIIA SUdSAAAIp SoyTSOAL
77 +> aeprlur0ulDy
Va ee OE Re sor yeess = VlopTyauoy
tt eteess og teeters og
ttt s2-2 oq sone srecet scenes | ores cees og
sore reeree eceees [eres oreo gg
SGOBSESGES GE5050| POSS OREO SGyary
cee ewww en nee. BESIO000 CGYG? Soda hace eects teh ala -- +> epodonprag
sete ces tee rece cere |see eee rece Op veces [eens sere creees [eect es og
core ss agprurodqelg Sia a tear eg Fg et tn! hehehe | Pein onda oe) [LO UL LR) Wy coor ca aad crib | sa PESSE OKT
7797 > eplyurarjuag
sree teste Op tre r|eet ees cece ee erence |eceeee creep ceces|ecre cerns ceeeec lees
groos sic XLPYISOAv,T
idieiiriemepeiinit: tae tesined | aiden aoe CO 1O1SU]
ahaa arate | Kew ar agi ig PLIVYJULOT
“VIVIGV YY
‘dOIMud SNOWAAINOAAVOIAS A9V SNOUTWHINOPYVO
Sac eth cath Scae a “"eyCULIOpOuUlyoy
--og ->* vozouny
CLASSIFICATION.
26
‘ua}VAg PUL POOAION vqogseaut sajauoYyD UIMG VAgINULIS sajauoyD
*pavumnyg snuvorxayy snjonpolg
‘UALTY SNJL[NOVaItUIOS snjonpoig
‘ua}VIg pUv POOAION snyworunu snjonpoig *Aqiamog snurdsisuoy snjonpoig
‘UM SISUdDSLIGAaN’ snjonpolg
unary, snjyejound snjonporg
*PpOOMION SnUtIUALAG snjonporg *AqdaMog snjqvj}soo snjonpoig
‘AYA VNSv.ys vsodAjog
*MOT[EMS Sieliasiq vrprpoudss
‘OJ AA. SIplosau awouoonry]4
SOG Gay O° 2050/009000'Gy5) S899 BaGOS390G Gy} S000 ERC OSCS5 (fa) FIOSO BE5H COSSO5 Gp FNSSS SSBOSO OCIS Gyan) c.0b0° SOOIOG OGG (a}5) FOCLG OBBO OBOO0 Gfp) ACID DOS Gy) CODE ss eee* Sepljoupolg SEESAG OOO Gp) CORO
oo
seeteeeessopcctt so-2 + eprodurAyy
tere eecees op cecec[ecsace tees ree eesderes eee og
tees eeeees op cree
seretr sees op cree tereeeeees op teres
tessereees op crc
sse+opcttt seestestess op ttre sees eeresrop crt seeees op crt vyewodomyty terete opcttt steteeeessop ctr o--> vyeuapouurky
*paplorsnpjoyyy
“VOSOTIOJW
‘IU JOyIpNAY stuvploowyo1y
*ALIOQMAN SNILUIO SULplOwByoIy
‘yao Mouqny A, UOOIjsOoyWT
-AausayDoy (7ava) wansayptoad umypAydoydoT *yaoJT VoLUDOXe styUdAyde7z
*AauSaYOOL VJENuavypnut viodosurksS eo Soploapuspoprdoey vaodiquioyy
‘QUIVET puv splvapgy snaosviodaypiu saya}VyO
“> eplivploxwyo1y aa oat sare GOO “> aepyudoyresD
seteeeeee op tte srt 55> LpIISOABT
"tr 757* vaplounpd Socio 056 (6
teseteeees op crt
tert eeeess op crt
ssooc > BIIBYyULOZ,
HE OCOO LG bene enee ay sosnioconcaygy
sere s2-- og rere sees og see ee22 0g sees eees og ---- vpodoryovig wees eees og sere eees so OSD ODOT LYNG (Oa
PROS OCC IAG ** B]LULIOPOULYI POOS'SHO Cag] PROD OOOO. CGY Ge DOHA OSOO Gy Gy SSSI SESS Gy PCOS ODSST GG
ss7>> vozouny
‘soioods pur viguas)
“ATU
*Iopsoqnsg
*IOp1O
*ssvjoqns
*sSt[D
“V.LVIGVY
‘ponunuoj—COINad SNOWAAINOPAVO ‘penuyuwoj—AOV SAOUWAINOGAVO
‘panutyuog—spssof wayjo pun aynagazaaue ayy fo 21Qn) oY mUajshy
27
CLASSIFICATION.
‘UIYOAA puL yoy vurvu sisdoonryy
“UdY}AO AA PUL Yaa snsopousod snyeydwony “UIYWOAA puL Yaoq snssvio uoydosayaq
“OP AA CUULS WUNITeJUAG
‘uapkeyy pur yxaoqq (-1va) vyvounoqns vusnolpy *MOT[EMG LapaaT] MQ SNPOZIYOS
‘uapAcyy pur yoayy vaied vippaaoyeg AQUSIYDI[ TAs evuryedyy
*(é) UdYIIOAA pur Yoo siysomamMoasvurped OIA ULL viaydouoyy
*(é) preumys vynovied vuurg
‘uopAvy pur yaayy ogo uayodojnomy UIYAO AA PUL Ysa] Snyvourpsojut uazoodornoay ‘AU AA Snuvfaioy usjoodopno1ay
‘prewnys sijzjuepios0 uaydadopnouy
veers ese * epronynen “+ +> eeprpeyduron yy *- eprnuoydosarpagq esd aah epiyeyuaq oor e =" epruryeuy RoOOG > epuosiy, seteeeeees op cree seer eeeees op cree Pete teeees op crete ores sees Sepia} SE IO SHENAE ST
soo + ussopsoluey, “77> vwyeyydopog -* vrypouviqouvsoiqy
"oro so* seprungsag
*- vyeIpULAqIUIIIg tetteteess op ces -- + essopsoprydiyyy “77> gyouos0Ua[oS sees eeeees op cre Sch Ses BILBAUL Gy, tetteeeses ope
sete eesees op eee te reeteees op cette tres eeeest op ete tecteseres op rest: tect eeeeesop errs rerteseees op eres: > +> ereAuloUO yy,
stereeees op eee:
opt COSDODOCO THEOL - vypeydasodoso1g
oes -0q t 2 -0q ss -0q epodo.aysex) = ---0q --og -*--0g
----0g +--+ -0q ttt -0qg
sees -0q ~ BIOFIIUOD
“DVL DISNIJOPT
“UOWIOP SUSPIAOq (eUSLJaTCT) e[NJeaqoioy, ‘sdipiyg eyvopnsouryd vaasiuds
TPH eunans vaiosiudg
NOdIVIA, MUOWLIOP, BIZ}OX
“Aqiamosg vyvoydoys0 vuriayids
*preumnys stsuaxpnjuey vurtayiidg “UY IO AA PUL YoY VJovsQUO “1A JaquIS (vuNazvy,) rapids ‘preumnys snxaauosouryd (vrunaeyy) tayiaidg *(é) ujazeyy snzerys razruds
nooivyy snuvjuourdysoy aaytuids
UOJIOJ] SNJVAOMILD JazIUIdS
‘OMY AA VOI[EJOU vjPauoyoudy yA
OUYM SIsuaypyese AA v[foUoyUAYY Noor vuvjuowAyoy v]auoyoudyy OIL, VI, E[[auUoYyoUAYY,
*XOD VILISOIOJLINYS LI[O99 Jy
ssdiqiyg viaystuiso sayuoidiuma zy
nosey usodag SIAC
"77> xeprlnyeaqaray, fete tesers op ttt:
wteetvewes op cree terteeeess op ctr settee sees op cree:
Regons aepropiuds peetlies 3 2 ay) Re
tere eeeees op rte sete eeeees op cree:
~ > xpyjeuoyoucyy
Be SotODiacaaa|
> g2pruautoydo1s
“OUUM Bjoudqeyd sajauoyD j---* *--7-* op > 77>
O Damian
Qype as (ga) HOQRS
(yp). POF O (@)o) POR QW op Op op PASH NO SO Gy AOSCA @yp) POD OD Bees. (0) oR oper: OD Geman
“=--0q
+2-2-0g -2-2-0q --=--0q
SOG Sas Gi SoS c OG, Seat OCi COSCE@YGT SO Oi Sa acl OG Sees (i DOSS ayEy BOSIO YG E
CLASSIFICATION.
28
ry
‘aT AA Stavpoaseyd (2) vULON (2) VIUOSIAL, “vyvauriquie viuoydodA “snyvpessvid snuivid900UT
‘uapAvZy pure yaar, snqveysyjeq sejauojduzy
‘OPAL SMIBAYS sayoouo;duey,
torreess-apyuan [7777 vuypeyjyydopog
©
sere eeeers opr ccttfectets certre es
soee> -- eplu0sIly, aes BROOD OSES SAA NER EH ET RTE ee eee te
serteeesssopcrte en OONO50 688080
G20D OOS 2H oteBeys[ |OIA Se Sean ot
“OUT MA, vNoaTISI1}s vaso |--7 7777 BplayjsO etry hare ra lca ea
“nae vISNIIO)Y
*VOSATIOW
‘uapAvpy puv Yoo SNOSHo}sv snUTIOvUS I
Scams WplulsiovjUs Gieciciziejemotoinie So seis rcs OO POUL, ey d Hoe
‘VIVIGVY
‘dormad ossvunt AOV OIOZOSUN
sere sees sr op crecs[esscse ster essee
»
“+= vssopSoprydiupy |oo77 777 > vow [77 ~* epodosaysecy seeeeeresr oper teeeee oq 2000 0000 TATA RIN (aT. JOPIeo 2989 CoSana|OOI00 CASH Gt
setts s-og
sccee sees op crece [eee ee eect seer eefeee tes os 0g
seeeee seep ccece[eceees cece cece ee|es teres 0g BOOS OFA ATAU LEIA [JOP OPOLCS OGO IOI OG GRE) HF BLEOIO)
Oooo
omen o loko ieee nein lean) CULL POUL OC
‘(g) uyof 3 pure ayy Masutdg snyyneN [ots 777 Op HTT re tes cireen eo OP Scheie BE OOS SISA 230090 (YQ *(g), Udy OA, pure yaa snyvy snqyNeNy [7777-77 eeprynenyy |--- 55 cian ciesias cies) ce = BD ROCEE (9) 6). 01 9oibE] PODER COCR OORCIED OPO Xa (i) === Gea) [POS Oo Eye te sitters) ||F92009 CoS coke OSSIAN BULAN BREE ores Sa me | - epodoyeydap, ‘ONY AA, SMAINSue snproyoosovpy |---* Lpyloyposovyy [7-7 Op Tyo Op m= scccissss'1Opiirse7|(wrewreinms OGL "ypayy asuaosvaqoNn svdaoAyeg |77- 77> 77 zepyndeg |------ essopsoluxy, | vyeiypouviqiuyoag |*7" 777" 77> voawrd |7 "~~ epodo.saysery) ‘soloads puv viauar) « hprare gy *Iapaoqns *IIp1O *ssvpoqusg *SSUIO
*‘panuluog—vlae vIsnpzopy
‘panunuod—COIMad SAOWAAINOAAVI ‘ponuyuwog—WOV SMOUAHINOAUYVO
‘ponuyu0gj—spssof wayjo pun aynaqazvanur ayy fo 2190} aynuashg
29
CLASSIFICATION.
IMT VAaNSury sorjsapodsryT
‘aU stenduu sayjsapodsry
“Yaa STUIOJISNY ¢ vINYouYy
“YT “Saploypivo (vypoyeya A ) CUTAN ‘yaoyy vroydozeurau vjnqi09
‘uapkeyy pur yaa vyepun (vypouda) vyjsidoray
MUM Wow (edwopisq) vyysidorT “OU AA Viduroour ¢ vayVYy
“yao vloydoruos vypatua,~,
‘yoo pur [ET eyepunqns vuony “aq. vssaidap vorvauopy
“ONY AA VuLod vuurg
IU AA SNplooey snuvess.0uyT
‘OUY AA SNIPIWUIpP snures1990UT
UOWOJW Iiqeieg snurves9.0uy
‘yoaTAL pure [ey syisey snurera0uyz ‘ao. SIULIOJap snwev1I90UT
*JOTIPS snoyeursyqoid snuvsa.0uy “IDWIOY SISUIOIV AA CUT
“OUYAMA Bssajetd sajoauojduey
OUYAA Slurp “va ‘Avg vyvjs09 viADOX TY *IDUIDOY L[NISMIAW] VAADOXIT ‘IauI90yY vso1dpuod viASox
. UOWOPY Woyoytg vayddary “OHI AA VNUpnid va.1ysC
terete cess op cere rete eeeees op cress 7777 apreyiiody ge xpyito Ny coonRads wxprnqiog Preeseetes op cee Brenaest epluneuy Toes ee LPMyoe Ay aioe ee * “spIsso|sy oe “7 >" eprulon’T Creat 7 ROREEN Pee Se SA gene tra tree teeeet op cre teceee sees op cece testes cess op cree
reset op cre teteee sees op cree iets "75" epittayg Py tea ae hbitia | cress" seprutjoag frtteetest op cre
trttee ees op ceece]es
teeeet prise so opcttet[rete cress op rite "o>" -ussojsouay | vyempuraqrunoag "7" vunpeyyydopog |---> essopsoprydry
nomen séoqEcGo6ANS terete seer op ctr:
trttet testes eeeees|seee sees es op cee
eee e ee ee ee eee eee eee Se rOD) eee--
ttttte cece es eens eee eee eee op cree
> vrieAW
rrrtctct se teee cece] teers eee op reese tere ttre stn ceeecs| teens eee op cee
cosets teeees cecees|eeeees eens op cere Sears wesececceees|-oeeceee ee gp cones
-oprttt:
tergee ceeeee ceecee| secs eee es gp -eeee senna nsecqD soucse|lscce scttt opr: Sebocs cogHos a6 aba0)|oo0065 0000 op 7777+
teose shop:
tet eeseeeces ccc ee | seen ee eee op cores
GNGO-D000.9 Gg) OO05/]0590:0000 e@yGr ademas nomen 1) Mossad |b ee saab © (3) OBOE DSS (ajpy IQOR|/POSo ORO HYG
momma COC) (a!
== -0g
GodoDe conbos conellod Gocece 2 od
treeeee[esee ess oq aaceHos terse -og
pret ccecee eee eee |e eee e ne og
setere cree ee cere |eeee eee og
oocaae +|ree- 222 0g
tresses -0g ttre ss -0g
tere sees 0g
pete secees op crete |ere eee eee ee eee fee eee beets op crete [retest eeeee freee] eeeeee es sogq "PBLUOD X9}109 VAIS |--- °°" --" plaasQ |---- te eros ere eee = vreAtMOMOyy [777-7 o> BSOROOS coos wrapIYUOD “vAaa vISnpOTY
“yooy] pur [[eyy vnqedsqns ernsury rato “7 aeprnsury Se LAr Se Se EO eal bree vyeuodok{
*vaplomsmgzoyy
“VOSA TIOW
‘dOldad SNOFOVLAND~
>>> vpodoryovag
CLASSIFICATION.
30)
“yao leaping (evuyntto[a, ) vuaika fold enone eepruatc:) titan teas or ate aca ate | es ca aechmatar NO 1 Oo ccd (ie Sea Gc lo an fae aes mn) IB
“Yoo SNJSNJOA OU)
> epruoi yg
“DAIL DISNIIO[ YT
“VOSN TIO
‘Goldadd AYVILYAL
HOV DIOZONGO
pci ates > vied Pa Aa Rantas are cra
77 > BrapIpUOD
ERIN CHIEN A aliers: [Joo PSCOcoe yp ebets) [Po CSOes cogs paGeAe| a oo aC sec AA eaiaNyp, |A2OdC? Coc RapRoa|conSanS SOULIO A, "VIVINOILUY i] ’ OUYAA BsuaTIVg svsgo0o ayy | 7777 Eqolbhipeaingy, eosCooscecos cacece So ce.Spemar= Opts |G ain SSS GES sae asa 2 OG: TGS ElEr GHIEBAGISEMOMy Pee o2eSe° yp) 92 220]|]2CO 968 POSOLG ORISA }2I9080 2S (a}8) SACS ‘OY AA SNULIAD'T soytuomuMy [7777-77 Op ttt [roe peciegin sesso o)ai Sales ac aepeiaee ni eens
*pacvUINYS TAOT[LAAS svasoryong ‘uapAvyy pur yaayy tate A, sayydeyosg
“IVA SNIVAO SoqTTNoVg
AUS SNyvAo sayNorg
*yaoy, viuvde13 stsdojawpy
*peauog stsdourjaut (vizjtuMayD) vp[ruoqany, ‘Yoo VpNoruNy ¢ vppourrpnsy
“AUUTAN IPPYIUTAA edorsseD
*peluod vuLsvAN vI[I}TIAN
soo > aepnimowiay vroros epniydeyas
ae eos DUT eT cree ---epyoupy "> eprpeprueikg seer eteees op ccc
veer neeses op rrr
tree ce|eeeeee eres op cree:
-- op
pesBuscssigny seco Sorspjy eee
-- > epodoyeydag cera wettest og
od treteess og
*yaay a[esjuao uokwostuy |*---7* 77" Op 77777 vert ease o SOD wer ea| Geran sac Opi ana |o520°= 52s Op isan: |taacknes “-oq ‘UOMIOJ St[vaioq uoATIOSIUW |77 77777 -wplinjoay, |*77 7 -essopsotuay |--vjyerpurrqiuoag [777 777-7" waootq |---- epodosajseyy *sotoads puv viauery “ATUL T *Iap1oqus JOplO *ssvpoqns *SSUID
*ponuyuogj—v092 vosngjoyy
‘penuyuoj)—COTddd SNOWOVLYAD
‘penuwojy—HOV OlOZOSaN ‘ponunu0g—spssof wayjo pup aypaqajaaau ayy fo ajqn, oynuaghg
dl
CLASSIFICATION.
*(¢) —— sudo |---->* xprurpudd5 Sai as eke ace rece ena [era nee ein [J OOGLYS (hil parma aecomni ha sain [te aad chche vaovysniy
“VIVTINOILYY
*(¢) —— ésnivdiara
“OU M Snou0y snaedrar,,
‘uapkeyy pur yaoyA Stursojz1yo0.1} snavdiat~, ‘[[@H e109} stsvqomoy
‘uapAvyy pur Yaa SIsuaosvaqaN sIsvqoruoy ‘uapAvpy pur xo VJLULIvOMUD} SIsuqoIUOy Spa pur [eH MpleT xeH
OUYM syvutosatd esky gq
‘Yoo. sisuotaspig veskyq
*(é) —— siquouryg
“yao Stsuaye7 A siqiour,g
*(¢) ——_ unueyds |
tere eeeees op rcte:
sooo o> soprredrar a,
“rrots > eeprUurpeyy sore sets aepplaH verso cose sepiskt Poe ene sorte s eepreeuuiry
-9e-
teteeeeees op cree terete eres op cree teeter tees op cee B20BH395 ha) ORREH teretesees op cree "77" "> essopsorux y, sooere sss eprydoary
tort ereee sop ccs:
teeeee ters op ere ~~ vroydoyeurutoseg
torteeeers op crt: a000.00 ssh oprctt
tert ereees op crt:
test eeeess op cece settee eres op cere:
“so°=* -epuouNg |
tere cres sop cere
2502 fs) 2906 aaa a 75" Boel
trtetess sop cc “777 vlaytuowypng
tt trees -og SOB OSEO GY Gy ster ees tog
Ton == "Og terete -og
Saeeeey fat sett eees cog *-**vpodosaysey
tts 4--0q
a2 PRIMORDIAL PERIOD.
CEEAGE TERS sihy
LOWER SILURIAN AGE.
PRIMORDIAL PERIOD.
PLANTA.
CRY PTOGAMIA. CLiass THALLOGENES.
GENUS CRUZIANA D’Orbigny, 1842. Cruziana Linnarssoni White. Plate I, fig. 2 a, b, and e. Cruziana Linnarssoni White, 1874, Geog. & Geol. Exp. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 5.
Body not much flattened, oblong or subelliptical in outline, but nar- rowed and more or less pointed at the ends, one of which is a little more acutely pointed than the other; median furrow traversing the whole length of the body, the greater part of it being deep and distinct, but a part of it is usually more shallow.
Surface marked by few or no transverse rugz, but upon the more pointed end of some of the specimens there is a secondary furrow upon each side of the median furrow ; these converge to the point where they join the median furrow, but they disappear in the opposite direction before reaching the middle of the body. Upon others, an incipient furrow is some- times seen at each side of the half of the body that is more acutely pointed These are near to, and their direction is parallel with, the sides of the body. This character is shown in figure 2 @ and b, Plate I. Stipe rather small, attached about midlength of the body in the bottom of the median furrow, but it is, however, rarely preserved.
32
PRIMORDIAL PERIOD. aya)
Length of body from two and a half to seven and a half centimeters.
It is not improbable that the form represented by figure 2) and ¢ is specifically distinct from the form represented by figure 2 a, especially as the first-named form is quite a constant one among the specimens of the collec- tions. I have, however, not felt fully warranted by the collections yet made in separating them under a different specific name, but I have selected the form represented by figure 2 @ as typical of the species here described.
Compared with C. dispar Linnarsson, from the Primordial rocks of Vestergotland, it differs in being more pointed at the extremities and other- wise of different outline, and also in having few or none of the transverse rug that so distinctly mark that species. From C. grenvillensis Billings (Paleozoic Fossils of Canada, vol. i, page 101), it differs in outline, in having few or no transverse ruge or wrinkles, and in having a median furrow traversing its whole length instead of occupying only a part of its length as the furrow does in that species.
It is thought possible that the specimens of this species in the collec- tion may have been denuded of rugee before they became imbedded, because the surface of some of the slabs upon which they are found are strewn with small bodies that resemble detached rugee. On the other hand, such a supposition seems untenable, because some of those slabs are found to contain both C. Linnarssont and the following described species; the former being nude as usual, and the latter having their abundant rugze in place.
The specific name is given in honor of Prof. J. G. O. Linnarsson, the able Swedish geologist.
Position and locality—Tonto shale, probably of the Primordial period, Grand Canon of the Colorado River, Mohave County, Arizona.
Cruziana rustica White. Plate I, fig. 1 a and b.
Cruziana rustica White, 1874, Geog. & Geol. Exp. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 5.
Body more or less elongated, flattened, more or less distinctly bilobed, the lobes being depressed-convex and the ends blunt; median furrow extending the whole length of the body and comparatively shallow through-
3 °F
34 PRIMORDIAL PERIOD.
out; transverse rugz numerous, some of them interrupted, but others extending from the outer borders to the middle of the median furrow, arch- ing slightly as they cross the lobes.
Length of the body in proportion with the width variable; in some specimens (perhaps broken ones) the length and width being about equal, while in others the length is two or three times as great as the width. The width varies in different specimens from three and a half to more than four centimeters. It is not improbable that this species reached a much greater length than is indicated by any of the specimens in the collection, and that even the longest of these are only fragments. No indications of a stipe arising from the median furrow, such as is seen in C. Linnarrsoni and other species, have been observed.
This species is larger than C. Linnarrsoni, with which it is associated ; of very different aspect and of different and more variable proportions. It somewhat resembles C. bilobata (Fucoides bilobatus Vanuxem, Geology of the Third District of New York, page 79) of the Clinton group; but the proportions of the body and of the lobes, respectively, are different.
Position and locality—Tonto shale, probably of the Primordial period. Grand Canon of the Colorado River, Mohave County, Arizona.
ANIMATLIA.
MOLLUSCA.
MOLLUSCOIDEA.
CLASS BRACHIOPODA. Orver LYOPOMATA.
Faminy DISCINIDA. GENUS ACROTRETA Kutorga, 1848.
Acrotreta? subsidua White. Plate I, fig. 3 a, b, c, and d.
Acrotreta? subsidua White, 1874, Geog. & Geol. Exp. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 6.
Shell thin, corneus, discoid, subcircular or somewhat suboval in out- line, the transverse diameter being a trifle greater than the longitudinal ;
PRIMORDIAL PERIOD. 35
sides regularly, and front broadly, rounded; posterior margin slightly straightened, forming a comparatively short, slightly convex, or nearly straight hinge-line.
Dorsal valve flattened; beak marginal or nearly so, not prominent; interior surface having a slightly-elevated median ridge, beginning beneath the beak and extending to about the middle of the valve, where it disap- pears.
The condition of all the specimens of this species which the collections contain is such that the muscular impressions are not distinctly shown, but those of the posterior adductors appear to be small, and placed nearly beneath the beak, one on each side of the median ridge just mentioned ; between these muscular impressions and the posterior margin there is, at each side, an obscure diverging ridge, or fold, which seems to blend with the postero-lateral margin.
Ventral valve moderately convex in the umbonal region, but more flattened anteriorly and laterally; beak excentric, somewhat prominent, and minutely perforate. Some of the specimens show what appear to be small adductor impressions placed in the apex, close to the foramen, one at each side of it. One specimen shows a slight flattening of the space upon the outer surface, between the apex and the hinge, producing the appearance there of an indistinctly-defined cardinal area.
The inner surface of both valves of all the specimens of this species contained in the collections has been more or less exfoliated by weather- ine, whereby some of the principal characters have been obscured. Con- sequently, the foregoing description is not only incomplete, but it is probable that the discovery of more perfect specimens may show necessity for modi- fying it. The cast of a single valve found associated with those used in this description, showing large and distinct muscular impressions, already suggests such a modification; but its characters are not embodied in the description, because that specimen is not certainly known to belong to the species. The specimen referred to is illustrated by figure 3 d, Plate I. The other specimens all show fine radiating lines in the structure of the shell, and also concentric laminz of growth. They are all compressed in
dark shale, and show only the interior surfaces of the valves, none showing
36 PRIMORDIAL PERIOD.
.
the external surface. The latter is supposed to be lamellose or otherwise so roughened as to have caused it to adhere to the shale, while the smooth interior surface has readily separated in the plane of fission.
This shell is not only specifically different from any other known to me; but in its want of a well-defined area and in its discoid, instead of pyramidal, form, it differs perhaps generically from those Discinid@ that are usually referred to the genus Acrotreta. I have referred it to that genus provisionally, because the combination of its characters renders its reference to any other established genus known to me equally inconsistent, and because the specimens are not complete enough to base a new generic description upon which the species may or may not possess.
Length of the largest specimen in the collection, six millimeters; width of the same, seven millimeters.
Position and locality—Strata of the Primordial period, probably of the epoch of the Potsdam sandstone, Antelope Spring, House range, Utah.
GENUS TREMATIS Sharpe, 1847. Trematis pannulus White.
Plate I, fig. 4 a and b.
Trematis pannulus White, 1874, Geog. & Geol. Exp. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 6.
Associated with Olenellus Gilberti Meek, a single imperfect spécimen of Trematis has been discovered, which, although consisting only of a single valve, possesses such characteristic surface-markings as to indicate its specific separation from all other known forms of the genus.
The diameter of the specimen is about three millimeters; outline apparently subcircular or a little broader than long; apex moderately prominent and situated near the posterior margin. Surface marked by a very fine net-work of oblique raised lines, dividing it wp into minute, four-sided, pore-like pits, which cause it to resemble, under the lens, the texture of finely-woven cloth.
In the character of its surface-markings, this species is nearly related to T. punctata Sowerby, sp., as figured by Davidson in his Monograph of British Fossil Brachiopoda, part vii, No.1. ‘That species, however, reaches
PRIMORDIAL PERIOD. 37
. a much larger size than our shell, and the small pits that similarly mark its surface are six-sided, instead of four-sided asin ours. The surface of T. siluriana Davidson, another allied species, has the pits arranged in radiat- ing instead of oblique lines.
Position and locality—Shales of the Primordial period and probably of the Potsdam epoch, Pioche, Nevada.
MOLLUSCA VERA.
CLAss GASTEROPODA.
Suspctass PTEROPODA. Orper THECOSOMATA. . Famiry HYOLITHIDA.
Genus HYOLITHES HEichwald, 1840. Hyolithes primordialis Hall (?). Plate I, fig. 5 a, b, c, d, and e.
Theca primordialis Hall, 1861, Geol. Surv. Wisconsin (pamph.), 48.
Theca vrimordialis Hall, 1862, Geol. Surv. Wisconsin, i, 21.
Theca primordialis Hall, 1863, Sixteenth Ann. Reg. Rep. N. Y. State Cab., 135.
Hyolithes primordialis Hall and Whitfield, 1873, Twenty-third Ann. Reg. Rep. N. Y. State Cab., 242.
Hyolithes primordialis ?, White, 1874, Geog. & Geol. Exp. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 6.
Shell slender, acutely pointed; test rather thin; transverse section sub- semicircular or subtrihedral; edges or longitudinal angles nearly or quite straight, meeting at an apical angle, varying in different specimens from fif- teen to twenty degrees; dorsal side slightly convex or nearly flat along the middle; ventral side forming a nearly semicircular arch in transverse sec- tion, but it sometimes shows an obtuse, rounded angle, extending from apex to aperture along the median line; the lateral angles, formed by the junc- tion of the dorsal and ventral sides, sharply rounded; margin of the aper- ture at the flattend side extended and broadly rounded; that of the convex side nearly transverse, but sometimes showing a slight emargination at the middle. Upon the flattened or dorsal side of the solid stony core of one of the specimens, from which the test is removed, there appears a very slightly raised longitudinal ridge, the width of which at all parts of its length is
38 PRIMORDIAL PERIOD.
about ‘one-quarter that of the whole width of the shell. This, of course, indicates the existence of a shallow, tapering, longitudinal groove upon the inner surface of the shell; but, so far as observed, there is no external indi- cation of its presence. Surface marked by lines and undulations of growth, which are apparently strongest upon the flattened side.
Length, from fifteen to eighteen inillimeters.
In the case of simple forms like these, it often seems necessary to take into careful consideration differences that, in more complex forms, would be considered as merely individual, or slightly varietal modifications, and there- fore disregarded. The difference between our specimens and those of Professor Hall, as represented by his figures and description, seems to be of this slight character; and it is only in view of the fact just stated that doubt is felt as to the specific identity of our shell with H. primordialis. The principal external differences (the internal characters of Professor Hall’s shell have not been made known) are that our forms are a little more robust, a little less flattened upon the dorsal side, and the convexity of the lines of growth and of the margin of the aperture at that side are a little greater. From H. gregaria Meck and Hayden, it differs in its greater size, its concentrically-marked surface, and in the outline of its aperture.
Position and locality—Strata of the Primordial period, and probably of the Potsdam epoch, Pioche, Nevada.
ARTICULATA.
CLASS CRUSTACEA. Orpver TRILOBITA.
Famity AGNOSTIDA. GENUS AGNOSTUS Brongniart, 1821. Agnostus interstrictus White. Plate II, fig. 5 a and b. Agnostus interstrictus White, 1874, Geog. & Geol. Exp. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 7. Head and pygidium of almost exactly equal size and general shape and otherwise closely resembling each other.
PRIMORDIAL PERIOD. 39
Head a trifle broader than long, regularly rounded in front; sides at the postero-lateral regions subparallel; postero-lateral angles truncated ; the whole exterior margin, including the truncated portions just named, pro- vided with a narrow, raised rim, the elevation of which forms a linear depression, or groove, between it and those portions of the head which it incloses; space between this marginal depression and the glabella a little wider posteriorly than it is in front, convex throughout, and its surface apparently smooth. Glabella conical, widest posteriorly, moderately con- vex, sides nearly straight, well defined by the dorsal furrows, abruptly rounded in front; a minute tubercle situated on the median line near the posterior end, and a shallow groove or furrow extending across near the front end, defining a frontal lobe of moderate size.
Thorax narrower than the head and pygidium, giving the body the appearance of being constricted at the middle; axial lobe broad, consisting of two segments, both of which are tumid at the ends adjoining the dorsal furrows; lateral lobes very narrow ; pleuree almost as wide as long; each pleura tumid, and rounded at its exterior end.
Pygidium having an outline like that of the head, and is also provided with a similar elevated marginal rim and linear depression within it; axial lobe a little longer than the glabella, and consequently that. lobe reaches a little nearer the posterior margin of the pygidium than the glabella does to the anterior margin of the head, moderately convex in elevation and also in each lateral outline; a minute tubercle is situated on the median line near the anterior end, corresponding in size and relative position with the one on the glabella before mentioned; space between the dorsal furrows and the margin convex, its surface apparently smooth; upon the outer edge of the border of the pygidium, at each side and alittle nearer to the axial extremity than to the antero-lateral angles, there is a minute protuberance, suggestive of an incipient spine. Besides the slight differences between the head and pygidium, already referred to, the pygidium differs also in having a faint appearance of segmentation of its axis and in a slight folding-backward of the marginal rim at the antero-lateral angles.
Length of body, eight millimeters; width of head and also of the pygidium, five millimeters; width of thorax, four millimeters.
40 PRIMORDIAL PERLOD.
This beautiful Agnostus is quite unlike any described American species, and is more nearly related to A. integer Beyrich, from the Primordial strata of Europe, than any other known-to me. Compared with that species, it is found to reach a larger size; its glabella is narrowed in front instead of having its sides nearly parallel; the axial lobe of the pygidium is nar- rower behind than in front, instead of being of nearly the same width at each end, and has the sides of that lobe convex instead of nearly straight, as they are in A. integer.
Position and locality—Shales of the Primordial period, probably of the Potsdam epoch, Antelope Spring, House range, Utah, where it is associated with Conocoryphe Kingii Meek, and other fossils of Primordial type, and where three entire specimens have been obtained, besides a number of fragments.
Famiry CONOCORYPHIDA.
GENUS CONOCORYPHE Corda, 1847.
SusGrenus PTYCHOPARIA Corda, 1847. Conocoryphe (Ptychoparia) Kingii Meek. Plate II, tig, 2 a, b, and e. Conocoryphe (Conocephalites) Kingii Meek, 1870, Proc. Acad. Nat. Sci. Phila., 63. Conocoryphe (Ptychoparia) Kingii Meek, 1872, Geol. Surv. Montana, Idaho, Wyoming, & Utah, 487.
Outline of body ovate; the width compared With the length being about as two to three. Head semicircular, or nearly so; the exterior margin regularly rounded, and bordered by a narrow marginal rim, which is nearly of uniform width throughout, but is sometimes a little stronger in front of the glabella than elsewhere; posterior margin very slightly concave in adult specimens, but a little more concave in young ones; near the postero- lateral angle of the head, this margin bends abruptly backward, terminating in cheek-spines of moderate length; these spines in the adult extend back- ward to a point about opposite the second segment of the thorax, but in the young the spines are proportionally longer, and the whole head larger com pared with the remainder of the body. Glabella slightly elevated above the cheeks, clearly defined by the shallow dorsal furrows; its anterior end
reaching a point about one-half its own length from the front margin of the
PRIMORDIAL PERIOD. 41
head; width at the base, compared with its full length, about as seven to eight; sides straight or nearly so; anterior end abruptly and posterior end very broadly rounded; occipital furrow well defined, and continuous with a similar but rather broader furrow at each side, that extends across the cheek parallel with and near the posterior margin of the head, giving that margin a raised border ; lateral furrows absent or very indistinct in adult specimens, but in well-preserved young ones there are indications of four pairs of lobes. Facial sutures curving outward and forward from the anterior ends of the eyes, or from a point a little forward of their anterior ends, reaching the marginal groove within the raised border of the head at points a little wider apart than the eyes are at their anterior ends, then, bending somewhat abruptly inward, they cut the anterior margin; posteriorly, the sutures extend almost directly outward from the posterior ends of the eyes, then, by broad backward curves, which become more abrupt as they proceed, they cut the posterior margin of the head not far from its postero-lateral angles and just inside the bases of the cheek-spines.
Eyes rather small, slightly arching outward, placed well back toward the posterior margin of the head; visual surfaces narrow, our specimens show- ing no reticulations; other portions of the head apparently without surface- markings or ornamentation, except that some specimens show a very faint ridge extending transversely from the anterior end of each eye toward the anterior portion of the glabella, but ending at the dorsal furrows before reaching it.
Thorax longer than the head, measuring seventeen millimeters in a specimen having a head thirteen millimeters long, the same thorax measur- ing twenty-five millimeters wide at its widest part; axial lobe depressed, narrow ; sides straight, about two-thirds as wide as-one of the lateral lobes at the anterior end of the thorax, about one-third wider at its anterior than it is at its posterior end; segments thirteen in number, passing nearly or quite straight across the lobe; a slight transverse prominence usually seen at each end of every axial segment near the bottom of the dorsal furrows, producing the appearance there of a corrugated, raised line along the whole length of each furrow; lateral lobes slightly convex, a little widest about midlength; pleure nearly transverse with the axis of the body, nearly
42 PRIMORDIAL PERIOD.
straight, but arching a little backward at their outer ends; extremities abruptly pointed, the points directed obliquely backward, and also bent a little horizontally outward, so as to produce the appearance of a slightly- flattened, serrated border along each side of the thorax, each pleura hav- ing a well-defined groove, which is widest and deepest about the middle, and extends from the inner end to near the outer extremity, where it becomes obsolete and ends at the flattened tip.
Pygidium subsemicircular, comparatively small, only a little more than one-third as long as the thorax, regularly rounded behind, where it has a narrow, flattened border of nearly uniform width all around; axial lobe ending at the marginal border; segments indistinct, but five or six in num- ber are recognizable in some specimens; lateral lobes much depressed, twice the width of the axial lobe at the anterior end of the pygidium; seg- ments indistinct, but may be distinguished by their grooves, which are deeper than those that mark the limits of each; grooves curving backward, and, like those of the pleuree, becoming obsolete upon reaching the flattened marginal border.
The whole surface is apparently smooth, except that there are some faint indications of radiating strize upon the exterior portions of the head of well-preserved specimens, discernible only by means of a lens.
Length of the largest specimen in the collections, five centimeters ; breadth of the same across the thorax, thirty-three millimeters.
Although this species resembles an Olenus in general outline and aspect, the possession of blunt and shortened, instead of extended and pointed, pleure, the presence of faint elevated lines between the eyes and glabella, the radiating lines upon‘ the surface of the head, together with the other characters above described and shown in the figures, leave no doubt as to the propriety of referring it to the genus Conocoryphe. The presence of only thirteen thoracic segments instead of fourteen (the number attributed to the genus by Corda) is not regarded as of generic importance in this case. ‘
A number of entire and more or less perfect specimens of this fine Trilobite ave contained in the collections, but they have all been a little flat- tened by compression. The finer details of structure of most of them have
PRIMORDIAL PERLOD. 43
also been obscured by contact with a peculiar accumulation of calcite or arragonite in the form of a layer from two to four millimeters in thickness beneath the whole crust; the crystalline prisms being vertical to the plane of the fossil and also to that of the layer of shale in which it was imbedded. Position and locality—Shales of the Primordial period, probably of the Potsdam epoch, Antelope Spring, House range, Utah. *
Famity ASAPHIDA.
GENUS ASAPHISCUS Meek, 1872. Asaphiscus Wheeleri Meek. Plate II, fig. 1a, b, ¢, d, , and f. Bathyurellus (Asaphiscus) Wheelert Meek, 1872, Geol. Surv. Montana, Idaho, Wyoming, & Utah, 485.
Body oblong-ovate in outline; surface smooth. Head depressed- convex; front margin regularly rounded; postero-lateral angles abruptly rounded, without cheek-spines; exterior margin bent shortly upward all around, producing a raised border of considerable width, and also a rather deep linear depression, or groove, parallel with that border and between it and the remainder of the cheeks. Glabella conical, much wider behind than in front, depressed ; space between its anterior end and the marginal groove about equal to the width of the raised marginal rim in front of it; outline well defined by the narrow dorsal furrows; sides nearly straight; anterior end abruptly and posterior end broadly rounded, without lateral furrows, or at least they are hardly discernible; occipital furrow shallow, broad, but somewhat distinct and uniform, extending entirely across the glabella, and continuous with furrows similar to itself that extend to the postero-lateral angles of the head; the latter furrows lie parallel with and near to the poste- rior margin of the head, giving that margin also a raised border, somewhat like the one upon the exterior margin. Eyes comparatively small, crescentic, situated nearly opposite the mid length of the glabella, and nearly equidistant from it and the posterior margin.
Thorax having nine segments; its length not quite so great as that of the head; axis broadest anteriorly, more strongly convex, and about one- third narrower than the lateral lobes are; segments extending straight across the lobe; lateral lobes depressed, their greatest convexity along the middle ;
44 PRIMORDIAL PERIOD.
pleurze bluntly poiated at their outer ends, the points not being directed very strongly backward; their inner ends so joined to the axial segments that they have the appearance of lapping a little upon them just inside the dorsal furrow; grooved, the groove being deepest about midlength, where the outer and inner portions of its front border meet at a distinct but very obtuse angle; grooves extending from the dorsal furrow nearly to the extremity of the pleure, where they disappear.
Pygidium somewhat semicircular in outline, distinctly trilobate ; seg- mentation indistinct, so much so in some of the specimens that the surface appears nearly as plain as that of an Asaphus, but the segmentation is usually more distinctly shown upon surfaces from which the crust has been removed; axis prominent, especially at its distal end, where it terminates abruptly at the inner edge of the broad marginal border; segments of axial lobe eight or ten; lateral lobes much depressed, a little wider than the axial lobe at the anterior end, and narrowing to an incurved point at the end of the axis; the whole exterior margin having a broad, flat border of nearly uniform width throughout; the under surface of this border marked by fine, somewhat irregular, longitudinal-stria, such as are usually seen upon corresponding parts of Asaphus.
The largest specimen in the collections is about seven centimeters long.
These specimens are the same that were used by Mr. Meek in his description of this species, and upon which he also based his genus Asaphiscus.
Position and locality—Strata of the Primordial period, probably of the ‘Potsdam epoch, near Antelope Spring, House range, Utah.
Famity PARADOXIDA. GENUS OLENELLUS Hall, 1861. Olenellus Gilberti Meek. Plate II, fig. 3 a, b, ce, d, and e.
Olenellus Gilberti Meek, 1874 (manuscript). Olenellus Gilberti White, 1874, Geog. & Geol. Exp. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 7.
Head subsemicircular or semi-oval, the length being to the breadth at the posterior border about as four or five to seven; both the external and
PRIMORDIAL PERIOD. 45
e
posterior margins bordered by a narrow, continuous, slightly-raised rim, that of the external margin being* placed a little within its edge, that of the posterior margin continuous across the occipital lobe of the glabella; the postero-lateral angles produced into slender spines, which are terete, very slightly incurved, not much widened at their bases, and in our speci- mens are about equal in length to one-fourth of the transverse diameter of the head at its base. ‘The posterior margin of the head, near each postero-lateral angle, bends abruptly forward a little, forming a kind of notch or small retreating angle with the backward-projecting spine, and also giving the outer corner of the movable cheek the appearance of being rounded. Eyes narrow, broadly arching outward, narrowness and con- vexity of curve both increasing posteriorly; their outer margins nearly equidistant from the center and the outer margins of the head, which dis- tance is also about equal to the length of the eye. Glabella distinctly lobed, the furrows extending nearly or quite to its center; frontal lobe much larger than the others, subcircular in outline, prominent, tumid, regularly rounded in front, and a little wider than the remainder of the glabella; anterior, middle, posterior, and occipital lobes of nearly uniform size.
The remainder of the body is unknown, with the exception of single specimens each of the long third pleura of the right side, and one of the others, probably belonging behind the third segment. The long one is broadly and somewhat deeply grooved upon the surface of its inner por- tion, where the anterior edge of the groove is elevated, the groove becom- ing shallower and narrower upon the outer portion, and finally disappearing toward the point of the pleura; outer portion of the pleura bending strongly but not very abruptly backward, and ending in a strong, flattened, spine-like point. The other pleura mentioned is grooved like the long one, but the anterior edge of its immer portion is not turned upward, as it is in the other.
The specimens of the collection are all imperfect, consisting only of flattened impressions in shale. Consequently, the character of the crust, the surface-markings or ornamentation, if any existed, and the original
convexity of the head are all unknown; but there are indications that the
46 PRIMORDIAL PERIOD.
convexity of the head must have been considerable, and that the specimens have been much flattened by pressure. * When perfect specimens shall be discovered, they may probably necessitate a modification of the foregoing description, but itis believed that such discovery will not necessitate material change. ‘The specimens of the collection are of various sizes, due to differ- ence in age; the transverse diameter of the head being from one and a half to five and a half centimeters.
This species is nearly allied to O. Vermontana Hall, from strata in Northern Vermont, generally referred to the Potsdam epoch; but it differs in many respects, the following being among the more important differences that appear upon comparing our specimens with the figure and original description of that species: —
The frontal lobe of the glabella of our species does not reach the ante- rior margin of the head by a space nearly equal to one-third the length of that lobe, instead of coming in contact with the frontal margin as in 0. Ver- montana. ‘The anterior ends of the eyes of our species reach forward nearly into contact with the anterior lobe of the glabella, being considerably farther forward than they are represented to reach in the figures of the Vermont species. In our species, the raised marginal rim of the posterior border of the head extends continuously across the occipital lobe of the glabella, but the figure and description of O. Vermontana represent no such raised rim. ‘The posterior margin of the head of our species is rounded forward at the postero-lateral angles, while the figure of O. Vermontana represents the posterior border of the head as curving backward, and forming sharp, spine-like angles with the lateral margins. The short cheek-spines of that species are represented as widening at the base ; in ours, the cheek- spies are longer, more slender, and do not thus widen. The long third pleura of O. Gilberti is not bent backward so abruptly as it is in O. Ver- montana, and the former species seems also to have reached a larger size than the eastern one.
Position and locality—Strata of the Primordial period, probably of the Potsdam epoch, Pioche, Nevada, and at Ophir City, Oquirrh range, Utah.
PRIMORDIAL PERIOD. 4%
Olenellus Howelli Meek.
Plate HI, fig. 4 a and b.
Olenellus Howelli Meek, 1874 (manuscript).
Olenellus Howelli White, 1874, Geog. & Geol. Exp. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 8.
Head massive, semi-oval in outline, strongly convex, the length on the median line being to the greatest breadth about as three to five; exterior margin having a strong, raised border, of nearly uniform width all around, and which is also continuous with the moderately strong spines of the postero-lateral angles of the head; length of the spines about equal to one- half the length of the head on the median line; posterior margin also having a raised border extending on each side from the occipital segment to the base of the spines, but not crossing the glabella upon the occipital lobe ; width of this border not uniform like that of the exterior margin, but is widest a little beyond the midlength at each side, and narrowest near the base of each spine, toward which it again suddenly widens, blending with both the spine and the exterior raised border; this widening of the border there rounds the angle between the posterior margin and the spine, and also rounds the postero-lateral angle of that portion of the cheek which is inclosed within the raised borders. A shallow, linear depression extends around the head just within the raised border, giving the broad cheek- surfaces the appearance of being slightly inflated.
Eyes large, very prominent, extending from opposite the anterior ‘ furrow of the glabella to nearly opposite the middle of the occipital lobe ; the palpebral lobe of each eye blending with the outer ends of the anterior, middle, and posterior lobes of the glabella.
Glabella large, very prominent, distinctly lobed; the furrows, while they are distinct at the sides, are only slightly impressed at the median line; occipital and posterior lobes of about equal size; frontal lobe large, tumid, well defined, extending forward to the shallow, linear depression just within the raised border of the anterior margin of the head, regularly rounded in front, a little wider than the remainder of the glabella, but not higher than the others of its lobes.
48 PRIMORDIAL PERIOD.
Surface apparently smooth but the condition of the specimen is such that this character is not clearly shown. Remainder of the body unknown, the only specimen discovered consisting of a well-preserved head alone. Associated with it, however, the spinous extremity of a pleura was found that possesses the characteristics of similar parts of Olenellus, and which probably belonged to an individual of this species.
This species is apparently related to O. Thompsoni Hall, from rocks in Northern Vermont referred to the Potsdam epoch, where it is associated with O. Vermontana ; but it differs in general outline and proportions, and also in many details, as shown by comparison with the figures and original description of that species by Professor Hall. The frontal lobe of the glabella in O, Howelli is wider than those behind it, instead of being nar- rower than the hinder ones, as they are represented to be in O. Thompsoni. The details of the exterior and posterior raised margins are different, and the postero-lateral spines are not proportionally so strong in our species as they are represented to be in that oné. The occipital furrow in ours does not extend so distinctly across the glabella as it does in O. Thompsoni, and the occipital lobe is proportionally wider, and extends farther backward than it does in that species. It is also related to O. Gilberti, but differs in gen- eral proportions of the head, the details of the exterior and- posterior bor- ders, and in the proportional size of the different lobes of the glabella.
As the genus Olenellus is held by geologists to mark a distinct and characteristic horizon in American strata, its discovery in that distant locality is peculiarly valuable and interesting. It is also an interesting and significant fact that the two species here described respectively represent in their specific characters the two originally-described species of the genus found associated in the Primordial rocks of Vermont and Canada, as these are found associated in rocks of the same period in Nevada.
The specimens from which the descriptions of the two species of Olenellus herein recorded were made are tlie same that were used by Mr. Meek in his original descriptions and naming of the species.
Position and locality.—Strata of the Primordial period, and probably of the Potsdam epoch, Pioche, Nevada.
PRIMORDIAL PERIOD. 49
VESTIGIA.
Plate I, fig. 6 a and b.
From the same strata that contain Cruziana Linnarrsoni and C. rustica, the collections contain some thin pieces of siliceous shale marked by a number of series of minute tracks that were probably made by some small Crustacean or other Articulate. They consist of double rows of slight transverse depressions upon the smooth surface of the shale, with a plain space between each series of the double row, about half as wide as the width of a series, but in some cases the two series of tracks constituting the double row nearly meet in the center. Hach separate minute track or depression arches slightly, and, although very narrow, they are each nearly or quite as wide as the spaces between them are. In some portions, each separate depression appears as if it had been twice or thrice impressed with minute organs of locomotion of similar size and shape. The width of the double row is about three millimeters, and the transverse length of each separate impression or track is hardly more than one millimeter. There are about twelve impressions, or separate tracks, in the length of a centimeter.
The tracks pursue a slightly tortuous course; the longest series shown by the specimens in the collection having a continuous length of about six centimeters, but all of them are broken at both ends. No remains have been found associated with them that might indicate the characteristics of the animal that made them; but the narrowness and uniformity of ' the series, together with the fact that each separate minute track appears to have been repeatedly impressed by a series of similar organs of locomotion, seems to suggest vermiform characteristics, but it does not necessarily follow that the animal was a true worm.
The collections contain no other traces of animal life from these shales, and the formation has been referred to the Primordial period mainly upon stratigraphical grounds.
Position and locality—Tonto shale, Primordial period; Grand Canon of the Colorado River, Mohave County, Arizona.
4r
dO CANADIAN PERIOD.
CHAPTERIV.
CANADIAN PERIOD.
PROTOZOA.
CLASS RHIZOPODA. Orper FORAMINIFERA.
Genus RECEPTACULITES Defrance, 1827.
Receptaculites
(?).
The collections contain a single fragment only of one of these strange and interesting forms. It is too imperfect for specific characterization, but is noticed here to make the account as complete as possible of the faunal characteristics of the strata which I have referred to the Canadian period. It seems to be a fragment from near the base of one of those broad sac- or urn-shaped species such as have been described by Mr. Billings from strata of the same period in Canada. Both ectorhin and endorhin have been mostly removed by weathering, whereby the open ends of the numerous close-set cylindrical tubes that connected them are exposed.
Position and locality—Strata of the age of the Quebec group of Canada; Fish Spring, House range, Utah.
CANADIAN PERIOD. 51
RADIATA.
Ciass HYDROZOA. Orver HYDROIDA. Famity GRAPTOLITIDA.
GENUS PHYLLOGRAPTUS Hall, 1858. ‘Phyllograptus Loringi White. Plate III, fig. 1 a and b.
Phyllograptus Loringi White, 1874, Exp. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 9.
Stipe apparently having the usual quadripartite form of the genus; the foliate expansion having a somewhat irregular elongate-oval outline and a moderately narrow axis. Cellules leaving the axis at different angles with it m different parts of the stipe, ascending along the middle portion so as to form an acute angle with the axis, then sweeping outward with an increasing curvature to the lateral margins, where they are at right angles with the axis, or in some parts of the length of the stipe slightly recurv- ing. ‘Toward the apex, the cellules are less curved and form more acute angles with the axis. Each cellule gradually but slightly increases in size as it extends outward to the margin, where there are thirteen or fourteen in the space of a centimeter. Hach cellule is provided at its aperture with a strong, prominent, recurving lower lip, the edges of which in our example, it being compressed, have somewhat the appearance of spine-like appendages. The stipe being broken at the lower end, the shape of that part is known only by inference, and for the same reason the full length has not been accurately ascertained, but it was apparently about four centimeters long; width, at about midlength, one and a half centimeters.
This species has the general aspect of P. typus Hall, but it differs from that species in the size of its cells and the character of its cell-apertures. According to Professor Hall, P. typus has a maximum of twenty-six cells
52 CANADIAN PERIOD.
e
in the space of an inch, while our species has from thirty-four to thirty- six inthe same space. ‘That species is represented as having small mucronate appendages at the cell-apertures, which those of our species are destitute of, but are provided instead with a thickened projecting lower lip.
Dedicated to the memory of Mr. F. W. Loring, who was murdered by the Apache Indians in October, 1871, while a member of one of the explor- ing parties.
Position and locality—Strata of the age of the Quebec group of Canada; Fish Spring, House range, Utah.
MOLLUSCA.
MOLLUSCOIDEA.
CLASS BRACHIOPODA. Orprr LYOPOMATA. Famity LINGULIDA.
Genus LINGULA Brugniére, 1789.
Lingula? manticula White. Plate ILI, fig. 2 a and b. Lingula? manticula White, 1874, Exp. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 9.
Shell small elongate-subovate or subelliptical in outline, broadest at or a little behind the middle; beaks pointed.
Dorsal valve proportionally wider than the ventral, moderately convex; postero-lateral margins nearly straight, meeting at the beak at an angle of nearly forty-five degrees; beak small, depressed; front margin regularly rounded.
Ventral valve proportionally longer than the dorsal in consequence of the considerable projection of its beak behind that of the dorsal valve; the whole valve, except its prominent beak, corresponding nearly with the whole of the opposite one, but its posterior portion is a little more convex trans- versely than any part of the other valve is; the beak is more prominent
CANADIAN PERIOD. 53
and sharper, and the postero-lateral slopes straighter than they are in the dorsal valve. Surface of both valves having a smooth appearance, but fine concentric lines and obscure radiating striz are to be seen under a lens.
Length of the dorsal valve represented by figure 2 a, Plate III, six millimeters; width, four millimeters. This is the largest valve the collec- tions contain, but it is not improbable that the species attains a larger size.
This species in general aspect resembles Lingula acuminata Conrad, from the Calciferous sandstone formation of New York, especially in the narrow- ness of the posterior portion of the ventral valve and its slender beak; but it is not proportionally so broad anteriorly as that shell is, and in other respects the outline is materially different. The dorsal valve of our shell resembles the figure of a specimen that Professor Hall refers doubtingly to Lingula mosia, from the Potsdam formation of Wisconsin (Sixteenth Ann. Regent’s Report New York State Cabinet, plate 6, figure 1); but the ventral valve of ours is proportionally longer than that figure, which is understood to represent a ventral valve. If this supposition is correct, that species has proportions materially different from those of ours.
I refer this species with doubt to the genus Lingula, because the inter- nal characters of the shell are unknown, and because it is now generally admitted that among the linguloid shells of the older Paleozoic rocks, which were formerly referred to the genus Lingula without question, there are really several different genera, all distinct from the recent Lingula.
Position and locality.—Strata of the age of the Quebec group of Canada; Schellbourne, Schell Creek range, Nevada.
Famity DISCINIDA. GENus ACROTRETA Kutorga, 1848.
Acrotreta pyxidicula White. Plate III, fig. 3 a and bd.
Acrotreta pyxidicula White, 1874, Exp. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 9.
Shell minute; marginal outline subcircular or transversely suboval ; without observable mesial sinus or fold. Dorsal valve most prominent near the umbo; beak small, depressed, but well defined, hardly projecting
54 CANADIAN PERIOD.
beyond the hinge-line; cardinal angles rounded; hinge-line short, nearly straight; lateral and front margins regularly rounded.
Ventral valve obliquely depressed-subconical; apex acute, prominent, and perforated by a minute foramen; margin in front of the hinge-line regularly rounded; area small, triangular, nearly flat, the angles which it forms with the sides of the shell rounded. Surface of both valves smooth, or marked by very fine concentric lines of growth.
Width, two millimeters; length a little less; height a little less than - the length.
This species, although so minute, seems to be a well-marked one, and possesses all the usual external characteristics of Acrotreta, except that the ventral valve is not so capacious as it generally is in that genus. It differs from A. gemma Billings, from strata of the age of the Quebec group in New- foundland, in the less proportionate height of the ventral valve, and in the absence of a mesial sinus in the dorsal valve.
Position and locality—Strata of the age of the Quebec group of Canada; Schellbourne, Schell Creek range, Nevada.
Orper ARTHROPOMATA.
Famiry STROPHOMENIDA. GENUS STROPHOMENA Rafinesque, 1827.
Strophomena fontinalis White. BG Plate III, fig. 4 a, b, and c.
Strophomena fontinalis White, 1874, Expl. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 10.
Shell moderately concavo-convex or nearly flat; outline semi-elliptical ; width from one-quarter to one-third greater than the length; width at the hinge-line varying from a little more to a little less than it is just in front of the hinge. Ventral valve slightly convex or somewhat flattened; con- vexity greatest behind the middle. Dorsal valve slightly concave, and in other respects corresponding with the ventral. Hinge and interior of both valves unknown.
Surface of both valves marked by fine, uniform, rounded, radiating striz, which increase by bifurcation, and give the surface an appearance
CANADIAN PERIOD. 55
similar to that of the well-known Strophomena fragilis Hall, from the Devonian strata of New York and other States. Fine concentric striz are also visible under a lens.
Length, eighteen millimeters; breadth, twenty-four millimeters.
This species resembles S. recta Conrad in outline, but the surface- markings are quite different. It also bears a general resemblance to S. aurora Billings, but differs in having rounded strize of uniform size instead of the angular strize of variable size which that species possesses.
Position and locality —Strata of the age of the Quebec group of Canada; - Fish Spring, House range, Utah.
GENUS ORTHIS Dalman, 1828. Orthis Electra Billings (?).
Among the collections made at Fish Spring, House range, Utah, from strata of the age of the Quebec group of Canada, are a few imperfect specimens of a species of Orthis that is very closely related to O. Electra Billings (Paleozoic Fossils of Canada, vol. I, page 79), if it is not identical with it. In outline, convexity, and the fine striation of the surface, our specimens agree closely with it, but the size is considerably greater than that given for O. Electra. The width at the hinge-line of the largest speci- men is about sixteen millimeters.
MOLLUSCA VERA.
CLASS GASTEROPODA.
Suscrass DICECA. Orper RHIPHIDOGLOSSA
SUBORDER DICRANOBRANCHIATA.
Famity BELLEROPHONTIDA. GENUS BELLEROPHON Montfort, 1808. Bellerophon allegoricus White.
Plate III, fig. 6 a, b, and ec.
Bellerophon allegoricus White, 1874, Expl. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 10.
Shell not above medium size, rather ene unbilicated ; umbilicus
56 CANADIAN PERIOD.
very small; aperture expanded, greatest expansion at the sides, giving it a reniform outline; outer volution abruptly convex transversely ; lip having a moderately large deep notch in front, of uniform width, the sides being parallel, and rounded at the bottom; of equal width, and continuous with this notch, there is a slightly-elevated, rounded, dorsal band extending along the center of the volution until it enters the aperture. Surface-markings not preserved in any of the specimens of the collection.
Extreme width across the aperture, eighteen millimeters; postero- anterior diameter of the shell, seventeen millimeters.
Although the specimens are imperfect in some respects, they are suf- ficently well preserved to show that they represent a species quite unlike any other known to me from any of the older Paleozoic rocks.
Position and locality—Strata of the age of the Quebec group of Canada; Fish Spring, House range, Utah. .
CLASS CEPHALOPODA. OrDER TETRABRANCHIATA. Famity ORTHOCERATID A.
Grenus ORTHOCERAS Breynius, 1732. SusnGcenus CAMAROCERAS Conrad, 1842. Orthoceras (Camaroceras) colon White. Plate IIT, fig. 5 a, b, c, and d. Orthoceras colon White, 1874, Expl. & Surv. west 100th Merid., Prelim. Rep. Invert. Toss., 10.
Shell annulated, very slightly tapering; transverse section oval; siphuncle large, peripheral, in contact with one of the broadly-rounded sides, its diameter equal to about one-third the short diameter of the shell; septa smooth; convexity nearly uniform, reaching farther forward at the narrower sides than at the broader ones; annulations broadly rounded, passing sinuously around the shell, the sinuosity being greater upon one of the broad sides than it is upon the other; interspaces nearly corresponding in width and curvature with the annulations. Surface-markings unknown.
Long diameter, eighteen millimeters; short diameter, fifteen millime- ters; distance from center to center of the annulations, six millimeters.
CANADIAN PERIOD. D7
The only specimen contained in the collections is the one figured on Plate III. It has the appearance of being slightly curved, as shown in figure 5 c, which, if natural, of course removes it from the genus Orthoce- ras; but, as the specimen has been a little compressed at one end, it is thought the curvature is due to that cause alone. If originally straight, as it is thought to have been, it properly belongs to the subgenus Camaroceras of Conrad, as is shown by the large peripheral siphunele.
Numerous annulated species of Orthoceras have been published, but the one here described possesses characteristics that seem to clearly distin- guish it from them all. Compared with O. pulchrum Barrande, it differs in having sinuated instead of direct annulations, an oval instead of a circular transverse section, and in having a larger siphuncle, which is also peripheral instead of central. From O. annulatum Sowerby, as figured and described by Barrande (not Hndoceras annulatum Hall), it differs in its proportionally narrower annulations as compared with the interspaces, its oval instead of circular or nearly circular transverse section, and in its larger and periphe- ral instead of central siphuncle. From 0. dulce Barrande, it differs in its oval ustead of circular transverse section, and in its larger siphuncle, which is also peripheral instead of central. From 0. wndulostriatum Hall, it differs in the course of its sinuous annulations, which both species possess, and in its much larger and peripheral instead of central siphuncle. With 0. furtivum Billings from the Calciferous formation of Canada, it is closely related in the character, size, and position of the siphuncle, but differs in its oval instead of circular transverse section, and also in the direction and character of the annulations.
Position and lecality—Strata of the age of the Quebec group of Canada; Fish Spring, House range, Utah.
Faminry CYRTOCHRATID A.
GENUS CYRTOCERAS Goldfuss, 1833. (?) Among the collections from strata of the age of the Quebec group, at
Cyrtoceras
Fish Spring, House range, Utah, there is a specimen of Cyrtoceras, too impertect for specific characterization, but which resembles in general aspect
<
58 CANADIAN PERIOD.
C. metellus Billings, from the Quebec strata of Canada. The curvature and proportions are similar to those of that species, and the septa are equally numerous and close-set.
ARTICULATA.
CLASS CRUSTACEA. Orprr OSTRACADA. Famity CYPRIDINIDA. : :
GENUS LEPERDITIA Rouault, 1851. Leperditia bivia White. Plate IU, fig. 7, a, b, c, and d.
Leperditia bivia White, 1874, Expl. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 11.
Shell not quite equivalve, inflated, the greatest transverse diameter being about midlength and below the middle; obliquely subovate in out- line, widest behind the middle; the straight hinge-line about equal in length to two-thirds the entire length of the shell, and ending both poste- riorly and anteriorly in a small, distinctly projecting angle, which it forms with the anterior and posterior margins respectively; posterior margin obliquely rounded, and provided with a moderately broad, somewhat flat- tened border; anterior margin abruptly rounded, having also a similarly- flattened border; the flattening of the borders of both valves and at both ends becoming obsolete upon reaching the ventral margin, which is broadly rounded; ventral border of the left valve bent sharply inward, and even a little upward, producing a narrow, plain, area-like surface there, which tapers to a sharp point at each end, and is nearly equal in length to the hinge-line; ventral border of the right valve not bent inward like that of the left, but the general convexity of the valve extends to the ventral edge. Upon the ventral border of this valve, near its edge, there are two distinct, comparatively large pores, which open divergingly upon the surface; the
a
CANADIAN PERIOD. 59
distance between them being equal to a little more than half the length of the hinge-line. Eye-tubercle not detected. Surface apparently smooth.
This species agrees nearly in size with, and bears a close general resemblance to, L. Canadensis Jones, from the Calciferous sandstone forma- tion of Canada; but it may be readily distinguished from that species by the prominent angles at the ends of the hinge-line, the laterally-flattened anterior and posterior borders, the greater convexity below the middle, and by the presence of the two large pores at the ventral border of the right valve.
Position and locality—Strata of the age of the Quebec group of Canada; Queen Spring Hill, Schell Creek range, Nevada.
Collected by Mr. J. E. Clayton.
Orver TRILOBITA.
Faminty ASAPHIDA. GENUS MEGALASPIS Angelin, 1854.
Megalaspis belemnurus White.
Plate III, fig. 9. Megalaspis belemnurus, White, 1874, Exp. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 11.
Pygidium subtriangular in outline, moderately convex transversely, and only slightly convex along the median line; length compared with the width across its anterior end about as fifteen to twenty-two; each outer margin having a wide smooth border, the outline of which is only slightly convex except near the antero-lateral angles, where the convexity increases and the angles are abruptly rounded; anterior margin moderately convex; posterior extremity ending in a short spine-like process; segmentation some- what indistinct, but is most apparent upon the anterior portion of the axis; trilobation also rather obscure; axis depressed, slightly higher than the adjacent portions of the lateral lobes, its width equal to about one-half the width of a lateral lobe, ending posteriorly in the elevated terminal portion of the pygidium; dorsal furrows moderately distinct upon the anterior half of the pygidium but become obsolete posteriorly; lateral lobes slightly
60 CANADIAN PERIOD.
convex, indistinctly defined externally by the broad, nearly flat margina border; their inner sides more clearly defined, especially their anterior portions, by the dorsal furrows. Surface apparently smooth; but this character, as well as the remainder of the body, is unknown. ;
Length of the pygidium from the front end to the base of the caudal spine, fifteen millimeters; width of the same between the antero-lateral angles, twenty-two millimeters.
This species is closely related to Asaphus (Megalaspis) goniocercus Meek; but it differs from that species in its less distinctly triangular outline, its greater proportionate width, its proportionally narrower axis, and rather more distinct dorsal furrows. In general aspect, the pygidium of our species resembles that of a Dalmanites, but the obscure trilobation and segmenta- tion separate it from that genus. It has not so complete a consolidation of the component elements of the pygidium as Asaphus has; and no striation of the under surface of the marginal border has been observed, such as is common in the genus Asaphus.
Position and locality.—Strata of the age of the Quebec group of Canada; Queen Spring Hill, Schell Creek range, Nevada.
Collected by Mr. J. E. Clayton. ae
FammLy ———(?). GENUS DICELLOCEPHALUS Owen, 1852. Dicellocephalus ? flagricaudus White. Plate III, fig. 8 a and b.
Dicellocephalus flagricaudus White, 1874, Exp. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 12.
Pygidium contracted-fan-shaped; lateral lobes each consisting of three segments directed backward; the inner one of each side lying close to the dorsal furrow, nearly parallel with the axis of the body or converging a little posteriorly, and becoming obsolete upon each side of a small, but com- paratively wide, sloping border that extends around the posterior end of the axial lobe.
The middle pair of segments commence at the dorsal furrow of each
CANADIAN PERIOD. 61
side respectively near the anterior end of the pygidium, bend abruptly, and extend backward parallel with the first, and project beyond the border as converging posterior spines. he third and outer pair of segments com- mence anteriorly at the dorsal furrows, where they are very narrow, extend outward a little, then curving abruptly backward they lie parallel with the others and form raised lateral margins of considerable but unequal width to the pygidium, and thence they extend posteriorly as an outer pair of converging spines. Axis prominent, especially at its apex, where it terminates in a moderately distinct angle, about one-quarter wider anteriorly than posteriorly, well defined by the nearly straight dorsal furrows, and marked by five or six distinctly defined segments, which cross it almost transversely, but with a slightly sinuous course.
Length of the pygidium along the median line, seven millimeters; greatest transverse diameter, nine millimeters.
The collections contain only the pygidium of this species, and I have therefore referred it doubtingly to Dicellocephalus, although it might perhaps, with equal propriety, be referred to Amphion. It has a general resemblance to the pygidium of D. magnificus Billings, and a still closer resemblance to D.? cora Billings, from the Quebec group of Canada.
Position and locality—Strata of the age of the Quebec group of Canada; Schellbourne, Schell Creek range, Nevada.
62 TRENTON PERIOD.
CHAPTER V.
‘TRENTON PERIOD.
RADIATA.
CLASS HYDROZOA. Orper HYDROIDA. Famity GRAPTOLITIDA.
GENUS GRAPTOLITHUS Linneus, 1736.
SunGENus CLIMACOGRAPTUS Hall, 1865.
Graptolithus (Climacograptus*) ramulus White. Plate IV, fig. 3 a,b, ande. -
Graptolithus (Climacograptus) ramulus White, 1874, Exp. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 15.
Stipe slender, bifurcating; bearing cells upon both edges below the bifurcation and upon one edge only (the outer) above that point, so that each series of cells is continuous from the common, proximal, extremity to the distal extremities of the branches respectively. The body of the stipe throughout is moderately thin and flat, but the cells are inflated so that their transverse diameter is considerably greater than the thickness of the stipe; cells moderately large, each bearing upon its outer wall about mid-
*T am inclined to think that the two groups into which Professor Geinitz bas divided his genus Cladograpsus should be designated by separate generic or subgeneric names. In that case, it seems proper that his first group should retain the name Cladograpsus, which would replace Climacograptus of Profes- sor Hall, while the second group seems to agree with Didymograpsus ot Professor MeCoy. Possibly, how- ever, the peculiar character of the cells of the species above described may hereafter require a new generic designation.
TRENTON PERIOD. 63
height a slender outward-projecting spine. The cells are of peculiar shape, as shown in the enlarged figures on Plate IV, and their apertures appear to have been lateral, but of this I am not entirely satisfied. If they are so, it is rather remarkable that they are all upon one side, in view of the fact that bilateral symmetry of the stipe is so prevalent throughout the family.
This species has the general aspect of G. ramosus Hall from the dark shales at Norman’s Kill near Albany, New York, and before its microscopic examination it was supposed to be identical with it. It is found, however, to differ very materially in the form, of its cells and the character of the stipe, as may be seen by comparing our figures with those of G. ramosus on Plate A, Decade IJ, Geological Survey of Canada.
Among these differences, there is one at least that seems to modify its relation to the subgenus Climacograptus, and especially to that section of it to which G. ramosus is assigned by Professor Hall. 'This is the presence of inflated cells of irregular form, projecting from the general surface of the stipe, instead of having the cells short and square, and hollowed out of the body of the stipe,—characters which are understood to distinguish Cli- macograptus. Among the specific differences between our species and G. yamosus are the different proportions and shape of the cells, the presence of spines upon all of them in our species instead of upon a part only, and the position of the spines about midway instead above the cell-aperture as in that species.
Position and locality—Shales, probably of the age of the graptolitic shales at Norman’s Kill near Albany, New York; five miles north of Bel- mont, Nevada, where it is associated with the three following-described species.
SuBcENuS DIPLOGRAPTUS M’Coy, 1850. Graptolithus (Diplograptus) hypniformis White. Plate IV, fig. 4 a and b. Graptolithus (Diplograptus) hypniformis White, 1874, Exp. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 12.
Stipe simple, slender; sides flat; edges nearly straight and nearly parallel; the increase in width from the proximal or basal end toward the distal end being very slight, except near the base; serratures deep, narrow,
tt
64 TRENTON PERIOD.
sharply rounded or angular at the bottom: inner and outer sides both ris- ing at acute angles with the axis of the stipe, those of adjacent cells joi- ing together to form moderately long, slender, mucronate points, which are directed strongly upward between the cells. At the basal end of the stipe small, downward-diverging points are sometimes seen, such as those pos- sessed by G. Whitfieldi Hall, and other allied species; like those species also, ours has a slender, thread-like axis, passing longitudinally through the center of the stipe and extending beyond the distal cells; serratures, or cells, about twelve in the length of a centimeter, but they have the aspect of being somewhat more numerous, because of the narrowness of the cells occasioned by the acuteness of the angle which the cell-axes form with the axis of the stipe. Exterior width of the stipe between the mucronate points of each side often less than two millimeters, and seldom more. Length of stipe, from one to three centimeters.
Upon the pieces of graptolitic shale in the collections are numerous stipes doubtless belonging to this species, but most of them have their details of structure so far obscured that it is difficult to distinguish them; the mucronate points between the cells, being delicate, are often removed, in which case the serratures have a blunted appearance. 'The more perfect stipes have somewhat the aspect of portions of those of Hypnum, or other related mosses, which circumstance has suggested the specific name.
This species is related to G. Whitfieldi Hall from the graptolitic shales at Norman’s Kill near Albany, New York; but the prolongations of the cell- walls are mucronate, pointing upward, in ours, and not seteeform, pointing outward, as in that species. Ours is also a smaller and more slender species, and has proportionally narrower cells.
Position and locality—Shales, probably of the age of those at Norman’s Kall, near Albany, New York; five miles north of Belmont, Nevada, where it is associated with the last described, and also with the two following
species.
TRENTON PERIOD. 65
Graptolithus (Diplograptus) pristis Hall, (?).
Plate IV, fig. 2a and 8. ? Prionotus pristis Hisinger, 1837, Lethza Suecica, 114. Graptolithus pristis Hall, 1847, Paleontology of New York, i, 265.
Stipe flattened; outline of the broader sides sublinear or very elongate- oblanceolate; cells moderately large, their upper sides or apertures being transverse and the outer sides sloping directly downward and inward gives the edges of the stipe a distinctly dentate appearance as it is compressed in the shale. Like related species, this has a slender thread-like axis passing longitudinally through its middle and extending beyond the distant cells.
In my preliminary report on these collections, this species was con- founded with G. quadrimucronatus Hall?; fragments of the two species being mingled in the same pieces of shale. This circumstance modified my description of that species, but the correction is made in this report from the study of more perfect specimens. Our examples show some differences from the typical forms of G. pristis, but they correspond so nearly with them that I do not at present feel warranted in proposing a separate specific name.
Position and locality—Shales of the Trenton period, probably of the Utica epoch; five miles north of Belmont, Nevada, where it is associated with the two species last described, and also with the following one.
Graptolithus quadrimucronatus Hall (?). Plate IV, fig. 1 a and Db.
Graptolithus quadrimucronatus Hall, 1865, Geol. Surv. Canada, decade ii, 144. Graptolithus quadrimucronatus ? White, 1874, Exp. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 13.
Stipe quadrilateral, transverse section oblong, gradually but slightly increasing in diameter from the proximal or basal end to about midlength, where the maximum size is reached; cells opening on the two narrower sides of the stipe; their apertures opening obliquely upward, being narrow, transverse, four-sided slits of uniform size, about half as wide as the inter- spaces, their length equaling the full diameter of the stipe; the outer corner of each cell-aperture provided with a minute projecting point.
5F
66 TRENTON PERIOD.
The specimens of the collection are all compressed upon shale; but there are among them examples of stipes compressed in the various postures they happened to assume when prostrated. These enable us to make out the structure as above indicated with comparatively little difficulty. Without bearing in mind the quadrilateral form of the stipe, one may mistake the confusion of details which the laterally-compressed specimens exhibit for examples of two stipes of an ordinary Diplograptus lying parallel and com- pressed together; but the adjustment and uniformity of the parts show that they all belong to a single body.
This species, so far as can be determined from the specimens of the collection, is so closely like G. quadrimucronatus Hall, from the “Utica slate formation, Lake Saint John, east from Blue Point”, that I prefer to assign it provisionally to that species rather than to a new one. Our specimens, however, are more delicate and slender, and the mucronate points much less conspicuous than they are in the typical forms. The cells are also a little more prominent and the cell-apertures proportionally wider vertically.
Position and locality.—Shales, probably of the ave of those at Norman’s Kill, near Albany, New York; five miles north of Belmont, Nevada, where it is associated with the three species last described.
CLASS ACTINOZOA. Orpen ZOANTHARIA. Famity FAVOSITIDA.
GENUS MONTICULIPORA @Orbigny, 1850. Monticulipora Dalii Edwards and Haime. Plate IV, fig. 5. Chetetes Dalit Edwards et Haime, 1851, Monographie des Polypiers Fossiles, 266. Coral dendroid; the branches cylindrical, six or eight millimeters in diameter; surface marked by small, slightly-raised mammillations, distant
two or three times their own diameter from each other; calyces subequal in size, about one-quarter of a millimeter in diameter.
TRENTON PERIOD. 67
Our specimen presents no material difference from the figures and deseription given by Edwards and Haime, and it evidently belongs to that species. Their type-specimens were obtained by de Verneuil from strata of the ‘Trenton period in Ohio.
Position and locality—Strata of the age of the Trenton period; Silver Canon, Pahranagat range, Nevada.
GrENnus FAVOSITES Lamarck, 1816.
(?).
Favosites
Among the collections are some specimens of Favosites that were obtained from strata of the Cincinnati epoch, both at Silver City and Upper Mimbres Mining Camp, New Mexico. They have been mostly silicified, by which change their wall-pores and other minute details of structure have been obliterated.
The specimens have the general aspect of F. Gothlandica, and, indeed, of several other admitted species also. But in view of the small number of characteristics possessed by even well-preserved specimens of this genus that may be relied upon for specific discrimination, and also of the imper- fect condition of the specimens contained in the collections, no specific des- ignation is given them.
Famitry THECIDA.
GrEnus FAVISTELLA Hall, 1847. Favistella stellata Hall.
Plate IV, fig. 6 a, b, and c.
Favistella stellata Hall, 1847, Paleontology of New York, i, 275.
Columnaria alveolata Edwards et Haime, 1851, Monographie des Polypiers Fossiles, 309. Favistella stellata Hall, 1862, Geol. Wisconsin, i, 430.
avist ella stellata Dana, 1862, Manual Geol., 220; ib., 2d ed., 1874, 204.
Coral forming an irregular compact or subhemispherical mass; cells varying in diameter from two to four millimeters, the average being about three millimeters ; the number of sides of each cell also varying from four to seven; diaphragms numerous, flat, or nearly so, at their central por- tions, but are bent downward a little at their margins, where they join the
68 TRENTON PERIOD.
vertical walls, which gives them the appearance of being slightly convex ; some ten or twelve rays, or dissepiments, extend upon the surface of each diaphragm, from the walls to its center; walls well developed and vertically striated as if by undeveloped rays.
I am unable to perceive any specific difference between the specimens contained in the collections and those which I have collected from the localities that furnished Professor Hall with the type-specimens of the species.
Not having the means at hand for making a critical investigation of the grounds upon which Edwards and Haime referred this species to Colum- naria alveolata Goldfuss, rejecting both the genus and species as established by Professor Hall, I make use of the names given by the last-named author. I do this with little hesitation, not only for the reason just stated, but also because the fossil under consideration is widely known and generally recognized by that designation among American geologists.
The specimens of the collection are all silicified, by which means they have lost some of their finer markings and details of structure; but a few of the cells are in a fine state of preservation.
Position and locality—Strata of the Trenton period, Cincinnati epoch; Silver City, New Mexico.
Famity CYATHOPHYLLIDA. GENUS ZAPHRENTIS Rafinesque et Clifford, 1820.
Zaphrentis
(2).
Some specimens of Zaphrentis were also obtained from the strata of the Cincinnati epoch, at Silver City, New Mexico. They are either too imperfect or possess too few characters to distinguish them specifically, and they are noticed only for their generic value in a faunal summary of the strata of that region that I have referred to the Trenton period.
TRENTON PERIOD. 69
MOLLUSCA.
MOLLUSCOIDEA.
CLASS BRACHIOPODA. Orper ARTHROPOMATA.
Famity STROPHOMENIDA. GENUS STROPHOMENA Rafinesque, 1827. Strophomena filitexta Hall.
Plate IV, fig. 8
Leptena filitecta Hall, 1847, Paleontology of New York, i, 112. Strophomena filitecta Hall, 1859, 12th Reg. Rep. N. Y. State Cab., 70. Strophomena filitevta Meek, 1873, Paleontology of Ohio, i, 83.
Shell a little above medium size compared with other species of the genus; concavo-convex, semi-oval or subsemicircular in outline; widest at the hinge-line, or, in rare cases, a trifle narrower there than it is a little farther forward; sides generally forming an angle of about forty or forty- five degrees with the hinge-line; lateral and front margins continuously rounded, with a nearly semicircular curve.
Dorsal valve depressed or flattened in the umbonal region, but some- what regularly arching from that part to the front and lateral margins ; beak hardly distinguishable as such; area very narrow, projecting directly backward.
Ventral valve broadly concave, except near the beak, where it rises into a slight convexity; beak small, not prominent; area moderately high, its posterior or outer border sloping a little laterally but not forming an acute angle at the hinge-extremity with its cardinal or inner margin; foramen triangular and closed by a prominent pseudo-deltidium ; hinge-teeth well developed; dental laminze continuous from the bases of the teeth with a prominent ridge, which almost or entirely encircles the concave depression occupied by the muscular scars; this depression sometimes having a narrow ridge extending longitudinally through its middle; cardinal margin of the
70 TRENTON PERIOD.
area sharp ; anterior and lateral margins of the valve thickened and roughened by the vascular markings, which are much less distinct within the thickened border than they are upon it.
Surface of both valves marked by fine, close-set, radiating strice, often of somewhat unequal size, the smaller ones being those that are implanted at various distances from the beak between those that are continuous from it to the margins; under a lens, the radiating striae are seen to be finely crenulated by the crossing of numerous delicate concentric strie.
Compared with authentic specimens of S. filitexta, and also with those of associated species to which it is closely related, our specimens correspond most nearly with those of the species to which they are here referred, although they present some slight differences.
Length, twenty-two millimeters; breadth, thirty-four millimeters.
Position and locality—Strata of the Trenton period, Cincinnati epoch; Silver City, New Mexico.
Genus LEPTAINA Dalman, 1828.
Leptzena sericea Sowerby (?). Plate IV, fig. 7.
Among the fossils collected at Silver City, New Mexico, from strata that are unmistakably referable to the Cincinnati-.epoch, are a few imperfect specimens of Leptena that I refer with some doubt to the species generally recognized in America as JL. sericea Sowerby. The specimens are too imperfect to base a specific description upon, but enough is shown to indicate that if they are not specifically identical with L. sericea, they belong to a closely-related and representative species.
Grnus ORTHIS Dalman, 1828.
Orthis occidentalis Hall. Plate IV, fig. 11 a and b.
Orthis occidentalis Hall, 1847, Paleontology of New York, i, 127. Orthis sinuata Hall, ib., 128.
Orthis subjugata. Hall, ib., 129.
Orthis occidentalis Meek, 1873, Paleontology of Ohio, i, 96.
Shell moderately large, suboval or subquadrate in outline, the trans-
TRENTON PERIOD. 71
verse diameter being greater than the longitudinal; dorso-ventral diameter comparatively small in young shells, but it increases with age, so that some old shells are very ventricose ; hinge-line sometimes a little less than the greatest width of the shell, but generally about equaling it; usually, the antero-lateral margins are regularly rounded and the front a little emargi- nate; postero-lateral margins generally almost straight from about the mid- length of the shell to the extremities of the hinge-line, with which they form more or less distinct angles.
Dorsal valve more convex than the ventral, even in the young, and it increases in convexity with age more than the ventral valve does; greatest convexity at or behind the middle, an indistinctly-defined longitudinal depression, or mesial sinus, is observable in many shells, but in some it is absent, even at the front margin, and is represented only by a slight flat- tening of the valve in the visceral region; umbo prominent ; beak abruptly incurved; area moderately wide in the middle, narrowing to acute points at the extremities of the hinge-line, concave transversely ; foramen broad at base, triangular.
Ventral valve broadly convex, convexity greatest near the beak; sides very slightly convex transversely; mesial sinus scarcely defined on the posterior half of the valve, but in front it consists of a broad, usually very shallow depression, which becomes obsolete about the middle of the valve ; beak moderately prominent. area alittle wider than that of the dorsal valve, and, like that area, it ends in acute angles at the extremities of the hinge- line; this area less arcuate than the other, sometimes arching a little back- ward, sometimes vertical with the plane of the valve, and sometimes inclining a little forward; foramen triangular, a little higher than wide, extending to the apex of the beak.
Surface of both valves marked by distinct, prominent, radiating strie, which increase both by implantation and bifurcation, and are crossed by a few concentric lines of growth.
Mature specimens average about two and a half centimeters in length and three centimeters in breadth. The more gibbous specimens of that size sometimes reach nearly two and a half centimeters in dorso-ventral diameter.
72 TRENTON PERIOD.
Several varieties of O. occidentalis have been described as distinct species. ‘Those of the collections agree well with the typical forms of the species, but it is not unlikely that future examinations of the strata from which they were collected will reveal associated varietal forms similar to those of the typical localities. This shell is one of the most common of those which characterize the rocks of the Cincinnati epoch, having been found in strata of that age in Ohio, Indiana, Ilinois, Iowa, and Wisconsin, at which places it is understood to prevail in, if it is not confined to, the upper part of the group.
Position and locality—Strata of the Trenton period, Cincinnati epoch ; Silver City, Nevada.
Orthis testudinaria Dalman (?).
Associated with the foregoing at Silver City, New Mexico, some imperfect specimens of an Orthis were obtained that very closely resemble O. testudinaria, but they are not sufficiently perfect to allow of a satisfactory determination of their specific identity. Their association in the strata there with species that are undoubtedly identical with the common associates of O. testudinaria elsewhere adds force to the supposition that our specimens
belong to that species. Orthis plicatella Hall(?).
Plate IV, fig. 10 a, b, ¢, and d. Orthis plicatella Hall, 1847, paleontology of New York,i, 122. Orthis plicatella Meek, 1873, paleontology of Ohio, i, 108.
Shell rather small suboval or somewhat semi-elliptical in outline, wider than long; length of hinge-line generally a little less than the greatest breadth of the shell; sides regularly rounded to the front, which is broadly rounded with an elliptical curve.
Dorsal valve not quite so convex as the ventral, most prominent about the middle; beak depressed; area directed backward, narrow at the middle, and diminishing to a poimt at each hinge-extremity; foramen triangular, broad at its base, comparatively large ; muscular scars not distinctly defined, but are separated by a comparatively broad, slightly-raised, medial ridge ; cardinal process small, narrow, wedge-shaped, the larger end inward, not filling the foramen; cardinal sockets small; brachial processes moderately
TRENTON PERIOD. ie
strong, supported by a thin lamina in young shells, and by a still greater thickening of shell-substance beneath them in older ones.
Ventral valve gently arching from beak to front, and also from side to side; greatest convexity near the beak, which is abruptly pointed and pro- jects backward beyond the hinge-line; area wider than that of the dorsal valve, and like that area it diminishes to a point at each extremity of the hinge; foramen triangular, extending to the apex of the beak.
Surface of both valves marked by strong, elevated plications, which are slightly flattened, or have a narrow linear depression along the back, each interspace also having a corresponding slender, slightly-raised line along its middle. So far as observed, all the plications extend without interruption from the umbonal region of each valve to the margins. ‘The plications are shown distinctly upon the inner surface of the valves, especi- ally at the margins, where also slight linear depressions are seen that mark the places of the raised lines between the plications on the outer side. Very fine concentric strive are visible under a lens upon the outer surface, which, in consequence of erosion probably, are usually more distinct between the plications than upon them.
This shell is referred with doubt to O. plicatella Hall. It agrees with that shell in general characters, and yet it presents differences that are at least as great as those which separate O. jissicosta Hall from 0. plicatella. It is also much like O. tricenaria Conrad in some of its features, but seems to differ from that shell as much as from 0. plicatella. The differences from the latter are the continuity of all (?) the plications from the umbonal region to the margin without bifurcation or implantation, the slight flattening or depression of the back of each plication, and the presence of the slightly- raised lines at the bottom of the interspaces. Since the species is known to be a variable one, I am disposed to regard these differences as only varietal until further comparisons can be made.
Length of one of the largest specimens in the collection, fifteen milli- meters; breadth, eighteen millimeters; distance from center to center of the plications at the front margin, about one and a half millimeters.
Position and locality—Strata of Lower Silurian age, probably of the Trenton period; Fossil Butte, near Hico, Nevada.
74 TRENTON PERIOD.
Orthis biforata Schlotheim, var. lynx. Plate IV, fig. 9 @ and b.
Shell nearly equivalve ; width exceeding the length; hinge-line vary- ing in length from a little greater to a little less than the greatest width of the shell, usually a little less; cardinal extremities generally more or less prominent in either case; cardinal area present and nearly alike in both valves ; they are narrow, well defined, each having a triangular foramen ;' dorso-ventral diameter varying with age from equal to one-half the trans- verse diameter to the full extent of the same; in the latter case, the shells have a compact subglobose form. :
Dorsal valve having a prominent, well-defined mesial fold, sometimes a little rounded but often quite angular, narrow, but distinct at the beak, and rapidly increasing in width toward the front; lateral portions convex transversely, and regularly arching from front to rear; beak not prominent, but arching over the area, and nearly meeting its fellow of the opposite valve.
Ventral valve about equally capacious with the dorsal; convexity of its sides similar to that of the sides of the dorsal valve, having a deep sinus corresponding with the elevated mesial fold of the other valve; its beak also similar in size, prominence, and incurvature to that of the dorsal valve.
The surface of each valve is marked by from eighteen to twenty-six strong, usually angular, plications, either three or four of which are at the bottom of the mesial sinus, and either four or five of them upon the mesial fold. The plications at each side of the mesial fold and sinus are similar in character to the others; all being usually simple, or continuous from the beak to the margin.
Length, about twenty-five millimeters; breadth, about thirty-three millimeters.
Several varieties of this exceedingly variable species, both in this country and Kurope, have been described as distinct species. Its geographical dis- tribution being very great, and notices and descriptions of it having been published at various times and places during more than one hundred and fifty years, its synonymy has attained unusual magnitude and diversity.
TRENTON PERIOD. 75
It is too voluminous for transscription here, and the reader is referred to the great works of Davidson on the Fossil Brachiopoda for the most complete exhibition of it yet published. The specimens contained in the collection are all referred to the variety generally known as Orthis lynx HKichwald.
Position and locality—Lower Silurian strata of the Cincinnati epoch ; Silver City, New Mexico, where it is associated with equally well-known forms of that epoch.
Famity RHYNCHONELLIDA.
GENUS RHYNCHONELLA Fischer, 1809. Rhynchonella argenturbica White. Plate IV, fig. 12 a, b, c, d, and e.
Rhynchonella argenturbica. White, 1874, Exp. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 14.
Shell somewhat less than medium size, compact, subtrihedral in out- line; length and width nearly equal; maximum height in old shells nearly equal to the width; postero-lateral margins somewhat straightened or slightly convex; rostral angle from forty to forty-five degrees; antero- lateral margins rounded; front, viewed from the dorsal or ventral side, either sinuous or truncate.
Dorsal valve more convex than the ventral, abruptly arching behind the middle; break strongly incurved; mesial fold very prominent, distinctly defined even to the umbo, divided into either three or four prominent angular or sharply-rounded plications; sides regularly arching to the margins, both longitudinally and transversely, but become somewhat laterally flattened near the beak; each side marked by from four to seven plications, those nearest the mesial fold being of about the same size as those upon it, but they become smaller toward, and obsolete upon, the postero-lateral margins.
Ventral valve less capacious than the dorsal, and also léss strongly arched; beak prominent; mesial sinus deep, occupying about one-half the width of the shell at the front margin, its sides abrupt and its bottom bear- ing either two or three plications like those of the dorsal fold; sides sloping away from the edges of the sinus with less convexity than the sides of the
76 TRENTON PERIOD.
dorsal valve have, and become laterally compressed near the beak; plica- tions about seven on each side of the sinus, becoming smaller toward, and finally obsolete at, the postero-lateral regions. Both valves have the plications distinctly defined to the beaks, and, being sharply angular at the front, they give the margin there a sharply zigzag appearance. Besides the plications, the surface of both valves is marked by regular and distinct lines of growth, which appear more prominent upon the plications than between them, giving them a delicately-knotted or crenulated appearance in some shells.
Length and breadth, each about ten millimeters; height, about eight millimeters.
Separated valves of this species somewhat resemble those of R. sub- trigonalis Hall, and also, to a less extent, A. Anticostiensis Billings. From the first, it differs in its more compact form and its more elevated mesial fold; from the latter it differs, in similar particulars, and also in its greater approach to an angular outline.
Position and locality—Lower Silurian strata of the Cincinnati epoch ; Silver City and Upper Mimbres Mining Camp, New Mexico.
CLASS CONCHIFERA. Orver HETEROMY ARIA. Famity MYTILIDA.
GrENusS MODIOLOPSIS Hall, 1847.
Modiolopsis
(2).
Among the collections made at Upper Mimbres Mining Camp, New Mexico, are some specimens of a Conchifer that evidently belong to the genus Modlopsis Hall. They are too imperfect for specific characteriza- tion, and are noticed only for their generic value in stratigraphical determi- nations, and for the purpose of giving a full account of the fossils collected at that interesting locality.
TRENTON PERIOD. ial
CLass GASTEROPODA.
Supotass DICECA. Orper RHIPHIDOGLOSSA. SuBorDER PODOPHTHALMA. Famity MACLURAIDA. GENUS MACLUREA Le Sueur, 1818. (?).
On Amargosa range, at the head of Amargosa Desert, Nevada, a single specimen of Maclurea was found in a mass of rock not in situ. Like the
Maclurea
species last noticed, it is too imperfect for specific determination, and is noticed here only because of the value the genus possesses in stratigraph- ical determinations. The mass of rock in which it was found had not prob- ably been far removed from its original position, and therefore the presence of Silurian strata in that neighborhood is inferred.
Famity PLEUROTOMARIIDA. GENUS RAPHISTOMA Hall, 1847. Raphistoma trochiscus Meek.
Plate IV, fig. 13 a, b, and e.
Euomphalus (Raphistoma?) trochiscus Meek, 1870, Proceed. Phila. Acad. Sci., 61.
Shell small, sublenticular; spire very slightly convex; suture not dis- tinct; volutions three or four, flattened-convex both above and below, thin and sharply rounded at the outer side; inner or umbilical side not so sharply rounded as the outer; the inner third of the upper side impressed to receive the outer portion of the broadly-rounded lower side of the next volution within. ‘The inner edges of the volutions are separate from each other within the umbilicus, but the outer edge of each is so nicely joined upon the next outer one that the convexity of the outer part of the upper side of each volution forms a part of the continuous convexity of the spire.
78 TRENTON PERIOD.
Width of the umbilicus about equal to the transverse diameter of the aper- ture, which is a little greater than one-third of the full transverse diameter of the shell.
Transverse diameter of the shell, nine millimeters; height of same, two and a half millimeters.
_This shell differs slightly from the species. as described and figured by Mr. Meek (loc. cét.), but it is probable that it is not specifically different.
Position and locality—Silurian strata, probably of the Trenton period; Ewell’s Spring, Arizona (lower horizon).
SUBCARBONIEFREROUS PERIOD. G9
CHAPTER VI.
CARBONIFEROUS AGE. SUBCARBONIFEROUS PERIOD.
RADIATA.
CLAss ACTINOZOA. Orver ZOANTHARIA.
Famity FAVOSITIDA. Genus FAVOSITES Lamarck, 1816.
Favosites divergens White and Whitfield.
Plate V, fig. 4. Favosites White and Whitfield, 1862, Proc. Boston Soc. Nat. Hist., viii, 306. Favosites divergens White and Whitfield, 1862 (manuscript). Favosites divergens Winchell, 1865, Proc. Acad. Nat. Sci. Phila., 112. Favosites Whitfieldi White, 1874, Exp. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 15.
Coral irregularly flattened-convex or subhemispherical; cells abruptly diverging from the base, increasing interstitially; apertures unequal in size, the smaller ones being those of beginning interstitial cells; vertical walls comparatively strong; diaphragms thin, about three within a space equal to the diameter of a cell. Diameter of cells from two to three millimeters.
The only specimen which the collection contains is silicified and partly imbedded in limestone, so that the finer details of structure have been obscured; but it is sufficiently perfect to indicate with little or no doubt its identity with PF. divergens. So far as I am aware, no other species of this genus has been discovered in the Subcarboniferous rocks of North America, nor in any rocks of later than Devonian age. This statement is made upon the supposition that Mavosites? mancus Winchell from the Goniatite lime- stone of Indiana is nota true Favosites. ‘The type-specimens of this species were obtained from the Subcarboniferous strata at Burlington, Iowa, where
80 SUBCARBONIFEROUS PERIOD.
it is rare. When the description of the species was first published, the specific name was inadvertently omitted, but was added in manuscript to the copies of the memoir that were separately distributed. When publish- ing the preliminary report upon these collections, it was my intention to compliment my friend by giving his name to the species; but, finding that the manuscript name had been used in the publications of Professor Win- chell, I-erased the personal name and restored the original one, but the the typographical correction was inadvertently omitted.
Position and locality—Strata of the Subcarboniferous period; Ewell’s Spring, Arizona (upper horizon), where it is associated with the two follow- ing species.
GENUS SYRINGOPORA Goldfuss, 1826. Syringopora Harveyi White (?)
Among the fossils collected from the Subcarboniferous strata at Ewell’s Spring, Arizona (upper horizon), there are a few examples of Syringopora. Their specific characters, indefinite enough in the most perfect specimens of the genus, are obscured by being imbedded in hard siliceous limestone. They closely resemble S. Harveyi White from the Kinderhook formation of the Subcarboniferous period at Burlington, Iowa, and, as no other species of the genus is known to me in that horizon, they are referred to the species
named. CLAss ECHINODERMATA. Orper BLASTOIDEA. Faminy PENTREMITIDA. GENUS GRANATOCRINUS Troost, 1850. Granatocrinus lotoblastus White.
Plate V, fig. 3 a and b.
Granatocrinus lotoblastus White, 1874, Exp. & Sury. west 100th Merid., Prelim. Rep. Invert. Foss., 15.
Body subelliptical in outline by side-view; greatest breadth about the middle ; distinctly but not very deeply pentalobate at the base, truncate at top; base depressed; basal plates very small; radial plates apparently very short, and embracing only the lower extremities of the pseud-ambu-
SUBCARBONIFEROUS PERIOD. — ei
lacral areas; interradial plates long and narrow, apparently reaching the summit; a comparatively shallow vertical furrow extending along the mid- dle of each; pseud-ambulacral areas prominent, narrow, reaching down to, or below the plane of, the basal plates.
Our only example is silicified and partly imbedded in siliceous lime- stone, whereby the finer details of structure and ornamentation, including the structure of the parts at the anal side of the summit, are obscured; but the more conspicuous features are sufficient to indicate its specific separa- tion from any similar form known to me.
Height, nine millimeters; transverse diameter, seven millimeters.
In general aspect, this little Granatocrinus is much like G. melo (= Pen- tremtes melo Owen and Shumard) from the Subcarboniferous strata at Bur- lington, Iowa; but it differs from that species in its less robust form, and in not possessing the distinct longitudinal lobes that suggested to those authors its specific name.
In that species also, the pseud-ambulacral areas are more or less depressed .below the general surface of the interradial plates, while in ours those parts are the most prominent portions in the outline of a transverse section of the body. If the generic identification of this fossil as distinct from Nucleocrinus is correct, as it is believed to be, there seems to be no reason for questioning the Subcarboniferous age of the strata containing it, since the genus as thus restricted is understood to be confined to strata of that period alone. ‘The Subcarboniferous age of the strata is also indicated by other types of that period associated with this species.
Position and locality—Strata of the Subcarboniferous period; Ewell’s Spring (upper horizon), Arizona.
Orver CRINOIDEA.
Faminry PLATYCRINIDA. Grnus PLATYCRINUS Miller, 1821. (?).
Platycrinus Plate V, fig. 2.
Upon the weathered surface of a piece of limestone in the collections,
there are three or four more or less imperfect Crinoids. They are partly OF
82 SUBCARBONIFEROUS PERIOD.
imbedded in the limestone, and partly defaced by weathering. One of these is a Platycrinus, as shown by characters other than the body-plates, the exact outlines of which are obscured by the injury the specimen has suf- fered. The outline of the calyx is shown, however, being broad cup- shaped, the base slightly depressed at the middle; arms bifurcating two or three times; branches of arms slender; the whole upper part of the body prolonged into a proboscidiform dome, which has a height equal to about three times that of the calyx, and stands erect between the arms; stem slender, composed of joints of unequal size.
Breadth of the calyx about eight millimeters ; height, five millimeters ; height from base of the calyx to the top of the proboscidiform dome, two centimeters ; the arms were capable of being extended nearly a centimeter farther. The apparent breadth of the calyx has possibly been increased a little by pressure; but the general proportions have evidently not been much changed.
This species is a delicate one in all its parts. Except that it is not nearly so rubust, nor so large, it resembles P. levis Miller, as figured by de Koninck and le Hon (Recher. Crinoides du Terr. Carb. de la Belgique). Judging from the general features of the fossil and such details as its con- dition allows of beimg observed, it seems to belong to an undescribed species, but of this I am not entirely satisfied. In case the discovery of more perfect specimens should show the species to be new, I propose for it the name of P. verabilis.
Position and locality—Strata of the Subcarboniferous period ; Mountain Spring, old Mormon road, Nevada.
Famity ACTINOCRINIDA. Genus ACTINOURINUS Miller, 1821.
Actinocrinus viaticus White. Plate V, fig. 1. Actinocrinus viaticus White, 1874, Expl. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 16. Body below the arms broadly turbinate ; arms slender, somewhat flat- tened laterally, apparently numbering thirty in all, the two full rays and
SUBCARBONIFEROUS PERIOD. 83
one-half of another shown by the specimen bearing such proportionate numbers. The appearance of branching of the arms begins below the periphery of the body, where, starting as if for simple pairs, they almost immediately bifurcate, the two inner branches of the two pairs thus formed again bifureating at or just beyond the periphery, the two outer branches of each original pair remaining simple. Surface of the body-plates marked by sharp, radiating ridges, which give the whole surface below the arms a confused, cancellated appearance.
Breadth of the body at its periphery, about eighteen millimeters.
The body of this species resembles in general aspect that of A. probos- cidialis Fall, and also that of A. asperimus Meek and Worthen, both from the Subcarboniferous limestone at Burlington, lowa; but it differs from both in shape, in its more delicate surface-ornamentation, and in the different character and branching of the arms.
Position and locality—Strata of the Subcarboniferous period ; Mountain Spring, old Mormon road, Nevada.
MOLLUSCA.
MOLLUSCOIDEA.
CLASS BRACHIOPODA. Orper ARTHROPOMATA.
Famity PRODUCTID. GENUS PRODUCTUS Sowerby, 1812.
Productus parvus Meek and Worthen. Plate V, fig. 6 a and b. Productus parvus Meek and Worthen, 1866, Geol. Surv. of Illinois, ii, 297.
Shell small, subhemispherical, length and breadth about equal; length of hinge-line nearly or quite equal to the greatest breadth of the shell; margin regularly rounded from ear to ear by the convexity of the shell.
Ventral valve regularly convex, without central flattening or mesial
84 SUBCARBONIFEROUS PERIOD.
sinus; beak slightly incurved over the hinge-line; ears small; surface marked by fine, distinct, uniform stria, about two within the space of a millimeter, increasing in number by occasional bifurcation, rarely by implantation; faint concentric wrinkles are observable upon the posterior half, especially near the beak, and fine concentric strize are also to be seen under a lens. A few small erect spines are scattered over the surface of the ventral valve, but they become broken off in the imbedding rock, and their bases do not form a conspicuous surface-feature of the shell.
Length in a straight line from beak to front margin, twelve millime- ters; breadth, fourteen millimeters; convexity, about nine millimeters.
Meek and Worthen’s type-specimens of this species were obtained from the Chester limestone of the Subcarboniferous period at Chester, Llinois, and, so far as I am aware, the species has never been recognized elsewhere except at the locality that furnished examples to these collections. Com- pared with the figures and original description given by those authors, our shell is found to differ in no material characters from theirs; while compared with other known species of similar size and general aspect, they are found to possess characters that clearly separate them from our species. This species has a general resemblance to P. elegans Norwood and Pratten, also from the Chester limestone, P. arcuatus Hall, from the Burlington lime- stone, both of the Subcarboniferous group; and also to some varieties of P. longispinus Sowerby, from the Coal-Measure strata. It is most nearly related to a variety of the last-named species which is found in considerable num- bers near Santa I'¢é, New Mexico. In those shells, there is, however, more or less of a mesial flattening of the ventral valve; the ears also are more flattened and the hinge-line more extended than in the species under con- sideration. .
Position and locality—Strata of the Subcarboniferous period; Mountain Spring, old Mormon road, Nevada.
SUBCARBONIFEROUS PERLOD. 85
Faminty STROPHOMENID A. GENUS STROPHOMENA Rafinesque, 1827. Strophomena rhomboidalis Wilckins, * sp.
Plate V, tig. 5.
Conchita rhomboidalis Wileckins, 1767, Nachricht von selt. Verst., 77. Anomites rhomboidalis Wahlenberg, 1821, Acta Societat. Scient. Upsal. viii, 65. Productus depressa Sowerby, 1823, Mineral Conchology, v, 86.
ae) Leptena rugosa Dalman, 1826, Kongliga Vetens. Akad. Handl., 106. Leptena tenuistriata Sowerby, 1839, Silurian System, 623, 636. Strophomena depressa Vanuxem, 1842, Geol. Third District New York, 79. Orthis depressa Portlock, 1843, Geol. Lond., Tyrone, & Ferm., 450. Leptiena tenuistriata Hall, 1847, Paleontology of New York. i, 108. Strophomena rhomboidalis Lindstrom, 1860, Goth]. Brach., 371. Strophomena rhomboidalis Hall, 1867, Paleontology of New York, iv, 76. trophomena rhomboidalis Davidson, 1868, Trans. Geol. Soc. Glasgow, Paleoz. Ser., i, 16. Strophomena rhomboidalis Meek and Worthen, 1868, Geol. Surv. Illinois, iii, 426. Strophomena rhomboidalis Meek, 1873, Paleontology of Ohio, i, 74.
Shell varying in outline, but génerally subsemicircular, widest at the hinge-line; lateral and front margins bent strongly upward all around, the portion inclosed by the geniculated margin flattened in both valves; the surfaces of these flattened spaces marked by conspicuous concentric wrinkles that increase in size from the beak outward; area narrow in both valves, that of the ventral being a little wider than the other. Surface marked by fine radiating striz, which are nearly uniform in size, close-set, increasing both by implantation and bifurcation, most frequently by the latter method on the ventral valve and by the former method on the dorsal. Under a lens, minute concentric striz are usually to be seen, as is also the punctate structure of the test, upon exfoliated surfaces.
Breadth at the hinge-line, of the largest specimen contained in the collections, four and a half centimeters. They are often smaller than this, their proportions and outline being also very variable.
The geological range of this species is greater than that of any other
* This is one of the most widely known of all the species of fossil Mollusca, and by some of its varieties it is familiar to every geologist and collector. Mr. Davidson, in his well-known Monographs gives a large number of authorities who have written upon or noticed the species. The synonymy here given is selected for the purpose of indicating some of the principal points in its literary, history and to show tbe numerous generic assignments that have been made of it besides the various specific names it has borne.
86 SULCARBONIFEROUS PERIOD.
known fossil, which circumstance has naturally thrown much doubt on the real specific identity of specimens collected from rocks of different geological ages.
It appears under slight varietal forms in’ different formations, which, although not strongly marked, have served to induce some naturalists to separate them as distinct species; but after the scientific scrutiny these shells have had for more than a hundred years, no person has succeeded in pointing out characteristics which entirely satisfy naturalists that they really constitute more than one species. As thus specifically recognized, its range is from the Trenton period of Lower Silurian age to the Subcarboniferous period, and it is also’. a common fossil in both hemisperes. Therefore, whenever this species is found associated with Upper Silurian or Devonian forms, and more especially if found unassociated with other fossils, it has of itself no valuable significance as to the geological age of the strata in which it is discovered; but when found associated with true Carboniferous types, it is understood to indicate the Subcarboniferous age of the strata containing it, because that period is regarded as the extreme recent limit of the range of the species in time.
Position and locality—Strata of the Subcarboniferous period; Mountain Spring, old Mormon road, Nevada, where it was found associated with the Platycrinus and Actinocrinus herein described as well as with other Subcar- boniferous types.
Famity SPIRIFERIDA. GENUS SPIRIFER Sowerby, 1815. Spirifer centronatus Winchell. Plate V, fig. 8 a, b, and c. Spirifer centronata Winchell, 1865, Proc. Acad. Nat. Sci. Phila., 118.
Shell of medium size, usually subsemicircular in outline, broadest at the hinge-line; the cardinal extremities often cuspidate, but sometimes a little rounded; both valves moderately convex.
Dorsal valve broadly and regularly convex transversely, a little depressed at the lateral extremities; convexity abrupt along the median line from the beak to the middle of the valve, but from the middle to the
front margin it is very slight or nearly straight; area very narrow; beak
SUBCARBONIFEROUS PERIOD. 87
strongly incurved and projecting a little over the hinge-line; mesial fold distinctly defined from the front margin to the apex of the beak, where it is minute, but widens a little more rapidly near the front than elsewhere; it is not much elevated above the adjacent parts of the valve, but is distinctly separated from them by an interspace on each side of it, which is a little deeper and wider than those which separate the plications from each other.
Ventral valve regularly arching from rear to front; sides somewhat regularly convex, but like the other valve it is a little depressed at the lateral extremities; beak prominent, strongly incurved, abruptly narrowing to a point; mesial sinus distinctly defined from the front border to the apex of the beak, nowhere very deep, increasing uniformly in width toward the front; area moderately narrow, striated transversely; foramen triangular, nearly equilateral.
Surface marked by from thirty-four to forty-two small, rounded, dis- tinct plications, nearly or quite all of which are simple; the two plications that form the lateral boundaries of the mesial sinus a little larger than any of the others, gradually but slightly diminishing in size from the sinus to the lateral extremities, where they become obsolete. From four to six pli- cations are found upon the mesial sinus and fold respectively, all of which are similar to those upon the sides of the shell, except that the former diminish more rapidly in width toward the beaks. Concentric lines and undulations exist upon both valves.
Breadth at the hinge-line, about thirty-eight millimeters; length from beak to front, twenty-two millimeters; thickness, sixteen millimeters.
Professor Winchell’s type-specimens were obtained from the Subcar- boniferous strata at Cuyahoga Falls, Ohio, and seem, from the description, to have consisted of ventral valves only. His carefully-drawn description of that portion of the shell agrees so very closely with the corresponding part of ours that I should entertain little or no doubt of the specific identity of the two if it were not that he speaks of his shell as being very nearly like S. cuspidatus Hall (not Martin), which I understand to differ consider- ably from ours.
Position and locality—Subearboniferous strata; Mountain Spring, old Mormon road, Nevada.
SUBCARBONIFEROUS PERLOD.
io2) oe)
Spirifer striatus Martin, sp. Plate V, fig. 10 a.
Associated with characteristic Subcarboniferous forms at Mountain Spring, old Mormon road, Nevada, some specimens of the well and widely- known Spirifer striatus were obtained. They are all more or less imperfect, but their identity with that species seems unquestionable. The striae which mark the surface are regular and nearly uniform in size, and show no inclina- tion to become fasciculated as those of S. cameratus always do to a greater or less degree. The collections also_contain specimens, apparently of this species, from a higher geological horizon, which are noticed upon another page, among the Coal-Measure species.
Varieties of S. striatus have been described under different specific names from the Subcarboniferous rocks of the United States; but when com- pared with authentic specimens from the Carboniferous rocks of Kurope, I am not able to discover differences of specific value. In view of this fact, I have less hesitation in referring our specimens to S. striatus than I other-
wise would have. Spirifer extenuatus Hall.
Plate V, fig. 9 a, b, c, and d. Spirifer extenuatus Hall, 1858, Geology of Lowa, i, pt. ii, 520. Syringothyris Halli Winchell, 1865, Proc. Acad. Nat. Sci. Phila., 8.
Shell of medium size, much extended at the hinge-line; length from hinge to front usually a little less than the height from the ventral beak to the dorsal umbo.
Ventral valve capacious, subpyramidal, having a moderately deep sinus, which is well defined from front to beak, and rapidly widening toward the front; beak extended, pointed, its point a little incurved over the area; sides sloping from the beak to the hinge-extremities with little or no con- vexity of outline, and also little or no convexity to the front and lateral margins; area large, triangular transversely striated, flat or distorted a little by the twisting of the beak, and its inclination more or less toward the dex- tral side of the shell; fissure of the area triangular, nearly twice as high as
it is wide at the base; each of its lateral border-angles truncated by a shal-
SUBCARBONIFEROUS PERIOD. 89
low groove; a little more than one quarter of the length of the fissure from its apex closed by a slightly convex pseudo-deltidium.
Dorsal valve moderately convex, differing in degree of convexity in different directions from its middle, but is somewhat regular in all; front margin broadly and regularly rounded, except that the lateral extremities are more or less extended, and the central portion is emarginate by the infolding of the mesial sinus of the ventral valve; mesial fold moderately elevated, well defined from front margin to the beak, and increasing rapidly in width from beak to front.
Surface of both valves marked by from fourteen to eighteen rounded plications on each side of the mesial field and sinus, which become less distinct toward, and disappear upon, the lateral extremities; surface of both mesial fold and sinus plain, except that, in common with the surface of all other parts of the shell, it is marked by fine concentric lines of growth. Shell-substance distinctly punctate.
Breadth along the hinge-line, nearly four centimeters; height from ventral beak to dorsal umbo, eighteen millimeters; length from hinge to front margin, sixteen millimeters.
The transverse plate connecting the dental lamine, together with the tube, which it bears along the middle of its under surface (characters that distinguish the group of spiriferoid shells which Professor Winchell has separated under the generic name of Syringothyris), are concealed by the
of that group, those mentioned are doubtless present also. So far as external characters are concerned, no specific difference can be detected between our shell and Syringothyris Halli Winchell (loc. cit.). His type-specimens were obtained from strata of the Kinderhook formation at Burlington, Lowa, and Clarksville, Missouri. Those of Professor Hall were obtained from the same strata at the first-named locality. The want of material difference between the dorsal valve of Professor Hall’s species (the only part of the shell described and figured by him) and the corresponding part of Professor Winchell’s specimens, together with the fact that they are associated in the same strata at one of the typical localities, leaves little cause for doubting the specific identity of Syringothyris Halli and Spirifer extenuatus.
90 SUBCARBONIKEROUS PERIOD.
In the course of some extended remarks upon the genus Spirifer, Messrs. Meek and Worthen (Geological Survey of Illinois, vol. iii, 532) have shown that the original species of the genus possessed the same peculiarities of structure that formed the basis of Professor Winchell’s genus Syringothyris. They also show that the numerous species which have been generally regarded as typical forms of the genus Spirifer really belong to a eroup for which Koenig proposed the generic name of Trigonotreta long before the publication of Syringothyris. This being the case, a strict enforce- ment of the rule of priority in scientific nomenclature will require that Syringothyris be suppressed, and that all shells having the structure which characterizes that group retain the name of Spirifer; also that Keenig’s name Trigonotreta be applied exclusively to those ordinary forms which have so generally been referred to Spirifer, at least in a subgeneric sense. In view of the question thus raised, and being at present without the means of deciding it for myself by personal investigation, the generic assignments I have made of these forms in this report should be regarded as provisional only.
Position and locality—Strata of the Subcarboniferous period ; Mountain Spring, old Mormon road, Nevada.
Suparnus MARTINIA McCoy, 1844,
Spirifer (Martinia) peculiaris Shumard. Plate V, fig. 7 a and b.
ora
Spirifer pecutiaris Shumard, 1855, Geological Survey of Missouri, part 2, 202. Ventral valve arching regularly from beak to.front, the curvature being ereatest near the beak; sides convex; beak narrow, extended, incurved ; antero-lateral margins: broadly rounded; postero-lateral margins abruptly rounded to the short hinge-line; postero-lateral surfaces rounded backward to the small, indistinctly-defined cardinal area; foramen triangular, its apical end closed by a pseudo-deltidium ; mesial sinus shallow, traceable nearly to the beak, widening a little more rapidly near the front than elsewhere, nearly plain, but two faint, incipient plications are observable, one at each side, and also a slight flattening along its middle. Surface on each side of the
sinus marked by six or seven small, convex-flattened plications, which are
SUBCARBONIFEROUS PERIOD. 91
separated by very narrow interspaces, becoming smaller toward, and finally disappearing upon, the postero-lateral regions.
Only the ventral valve of this species is contained in the collections ; but that agrees in all essential characters with S. peculiaris Shumard, the type-specimens of which species were obtained from the Kinderhook for- mation of the Subcarboniferous group in Missouri. The principal variations which it shows from the typical forms as described and figured by Dr. Shumard are the incipient plications of the mesial sinus and the somewhat greater rounding of the postero-lateral angles. Possibly more perfect examples may show other differences also, but the characters so far observed do not seem to warrant a specific separation from S. peculiaris.
Position and locality—Strata of the Subcarboniferous period; Mountain Spring, old Mormon road, Nevada.
GENUS SPIRIGERA D’Orbigny, 1847. Spirigera monticola White. Plate V, fig. 11, a, b, c, and d. Spirigera monticola White, 1874, Exp. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 16.
Shell subelliptical or subtetrahedral in outline, always wider than long, widest at, or a little forward of, the middle, moderately gibbous; valves almost equally capacious; postero-lateral margins in old shells thickened, but in younger ones the whole margin is more or less sharp; front margin only slightly sinuous in very young shells, but it is very deeply sinuous in some old ones.
Ventral valve broadly convex from side to side, regularly arching from beak to front; beak moderately prominent and slightly incurved; foramen, as usual, nearly round, rather small; mesial sinus moderately narrow, scarcely apparent in young shelfs, but in some old ones becoming very deep at the front, where the margin is much prolonged upward to follow the fold of the other valve.
Dorsal valve gibbous in the umbonal region, prominent along the mid- dle, from which the sides slope away by gentle convexity to the lateral
margins; mesial fold rather narrow, and in some examples not well defined,
9? SUBCARBONIFEROUS PERIOD.
in which case the valve has a broad, nearly uniform, convexity; yet in others the mesial fold is well defined and prominent, especially at the front ; but in all cases it is hardly discernible behind the middle of the shell, even in adult examples. :
Surface of both valves marked by concentric lines, of fine lamelleer of growth, and occasionally indications of fine radiating striz are to be seen under a lens.
Length of an adult specimen of average size, twenty-three millimeters ; extreme breadth, twenty-nine millimeters; height, sixteen millimeters.
This shell is quite different from any other described species of the genus known to occur in American Carboniferous strata. The most nearly allied form with which I am acquainted is an undescribed one in the Subcarboniferous stata of Franklin County, Iowa, with which our species is probably identical. It somewhat resembles S. incrassatus Hall from the Burlington limestone, but it differs from that species in outline, the less prominence of the ventral beak, the character of the mesial fold and sinus, and in the surface-markings.
Position and locality—Strata of the Subcarboniferous period; Mountain Spring, old Mormon road, Nevada.
Spirigera obmaxima McChesney. Plate V, fig. 12. Athyris obhmaxima McChesney, 1859, Descr. New Paleozoic Voss'ls, 80 Spirigera pectinifera Swallow, 1863, Trans. St. Louis Acad. Sci., ii, 88.
Shell large, broader than long, greatest breadth about midlength; out- line suboval; ear-like projections of fibrous shell-substance sometimes seen upon the postero-lateral margins. Ventral valve broadly convex, bearing a broad, shallow mesial sinus upon the front half of old shells, obsolete upon the posterior half; greatest convexity at the tmbonal region; beak not very prominent, incurved.
Dorsal valve having its greatest convexity along the median line ; mesial fold indistinctly defined except at the front; umbonal region not prominent; beak strongly incurved beneath that of the other valve.
Breadth, six centimeters or more; length above five centimeters.
SUBCARBONIFEROUS PERIOD. 93
This species is remarkable for its great size, and, although the speci- mens of the collection are imperfect, I have hardly a doubt of their specific identity with S. obmaxima McChesney.
Position and locality—Subcarboniferous strata; Mountain Spring, old Mormon road, Nevada, and also at a locality below Ophir City, Utah.
Famiry TEREBRATULIDA. Genus TEREBRATULA Lhwhyd, 1698. Supaenus DIELASMA King, 1859. Terebratula (Dielasma) Burlingtonensis White.
Terebratula Burlingtonensis White, 1860, Jour. Bost. Soe. Nat. Hist., 228.
22
Shell of moderate size, subovate in outline, more or less gibbous, broadest a little forward of the middle.
Ventral valve regularly convex; beak prominent, projecting considera- bly behind that of the dorsal valve, moderately incurved ; a faintly-defined ridge at each side of the beak follows its curvature from the foramen for- ward, and disappears near the middle of the shell; dental plates moderately strong, their front edges sharp and perpendicular with the teeth, placed near the sides of the beak, and diverging a little as the beak increases in size ; mesial sinus absent or obsolete.
Dorsal valve depressed-convex, greatest convexity near the beak, which is not prominent; mesial fold absent. Surface smooth or marked by indistinct lines of growth; shell-structnre finely punctate.
Average length, about twenty-two millimeters.
The type-specimens of this species were obtained from the Subcarbon- iferous rocks at Burlington, Iowa, and those of the collections agree with them in all essential respects. The reference to the subgenus Dielasma of this species is made in consequence of the presence of dental plates, the other characteristics of the subgenus not having been observed. It differs from T. bovideus especially in wanting the longitudinally arcuate form, so constant in that species.
Position and locality.—Strata of the Subearboniferous period ; Mountain Spring, old Mormon road, Nevada.
94 SUBCARBONIFEROUS PERIOD.
MOLLUSCA VERA.
CLASS CONCHIFERA. Orver DIMYARIA, Famity CARDITDA‘(?). Genus CONOCARDIUM Brown, 1835. (2). From strata of the Subcarboniferous period below Ophir City, Utah, a
Conocardium
single example of a species of Conocardium was obtained. It is too imper- fect for full specific determination, but its observable characters indicate that it belongs to an undescribed species. It is similar in size and also in many of its details to C. trigonale Hall from the Corniferous limestone of New York and Ohio. The costee and interspaces, as well as the very fine con- | centric strize that mark the surface, are very similar to those of that species, but our shell differs in its smaller and more numerous coste, in being less produced at the antero-ventral angle, and in the more distinct rounding of the antero-lateral ridges.
In case the discovery of more perfect specimens should confirm the opinion that this shell belongs to an undescribed species, I propose for it the name of C. semiplenum.
CLass GASTEROPODA.
Susciass DICSCA. Orver RHIPHIDOGLOSSA.
SUBORDER PODOPHTHALMA. - Faminy EUOMPHALIDA. xENUS EUOMPHALUS Sowerby, 1815.
Euomphalus luxus, White.
Plate V, fig. 13 a and b.
Shell of medium size, subdiscoidal, the spire being only a little
elevated; volutions four or five; outer side of volutions convex below but
SUBCARBONIFEROUS PERIOD. 95
flattened a little above so as to form a more or less distinct angle with the flattened upper side; under side regularly and continuously rounded from the outer side into the umbilicus, where it meets the next volution within ; suture distinct; umbilicus moderately deep and broad. Surface marked by distinct lines and occasional corrugations of growth. Diameter of coil of the largest specimen in the collections, thirty-eight millimeters.
This species resembles LZ. latus Hall, the type-specimens of which were obtained from the Burlington limestone division of the Subcarboniferous group at Burlington, Iowa, and Quincy, Illinois. The specimens of the collection present differences from the typical forms of the species which I at first regarded as only varietal, but upon further examination I consider them specific; the principal of which differences are their smaller size, less rapidly increasing volutions, and the absence of the elevation, or incipient fold, upon the upper side of the volutions adjacent to the suture which characterizes . latus. ;
Position and locality—Strata of the Subcarboniferous period; below Ophir City, Utah, and also ‘near the base of the anticlinal”, at Ophir
City.
96 CARBONIFEROUS PERIOD.
Oat say eM ID IS WW Whe
CARBONIFEROUS PERIOD.
PROTOZOA.
CLASS RHIZOPODA. Orper FORAMINIFERA.
GENUS FUSULINA Fischer, 1837.
Fusulina cylindrica Fischer. Plate VI, fig. Ga@andb.
Fusulina cylindrica Fischer, 1837, Oryet. du Gouv. de Moscou, 126. Fusulina cylindrica D’Orbigny, 1845, Geol. Russ., ii, pt. ii, 16. Fusulina cylindrica Owen, 1852, Geol. Sury. Wisconsin, Iowa, and Minnesota, 131 Fusulina cylindrica Meek and Hayden, 1859, Proc. Acad. Nat. Sci. Phila., 26. Tusulina cylindrica Dana, 1862, Manual of Geology, 164. Pusulina cylindrica Meek and Hayden, 1864, Paleontology Upper Missouri, 14. Fusulina cylindrica Meek, 1864, Paleontology of California, pt. i, i, 4. Fusulina cylindrica Geinitz, 1866, Carbonformat. und Dyas in Nebraska, 71. Fusulina cylindrica White, 1870, Geology of Iowa, i, 250. Fusulina cylindrica Meek, 1872, United States Geol. Surv. of Nebraska, 140.
Shell varying from terete to subglobose, assuming all intermediate fusiform shapes, generally somewhat obtusely pointed, especially the terete ones, usually having the appearance of being slightly twisted at the ends; septal furrows moderately distinct, even upon unweathered specimens, extending in more or less direct lines longitudinally, but are a little deflected just at the ends; centrifugal apertures about twice as high as the thickness of the cell-wall covering them, more than twice as broad as high, and of nearly uniform size throughout the whole coil. The locular or external
aperture, since it varied with the progress of construction of the cell, and
CARBONIFEROUS PERIOD. 97
must have been fragile until it was completed, is seldom clearly shown upon the fossils. '
It was apparently linear, extending the full length of the shell until closed by a new longitudinal septum at each side, leaving only a new centrifugal aperture at the middle, in line with the others. Volutions from five to eight; septa from twenty to thirty in the outer volution; septa nearly straight at their outer or external edges, but laterally undulating at their inner edges, where they join the outer surface of the next volution within, as may be seen in specimens that have had a part of their outer volution removed by weathering; the same defacement also showing por- tions of the series of entrifugal apertures. The undulations of the inner edges of contiguous septa are not usually parallel; but the convexity of the folds of each septum generally comes opposite that of the folds of the next adjacent septum, which gives rise to a peculiar confused and complex appearance of the septa in those specimens that have suffered erosion or weathering of the outer volution.
Dimensions very variable; one of the more robust specimens in the collections being one centimeter long and half a centimeter in diameter ; another measures nine millimeters long and two millimeters in diameter.
Fischer described another species, together with I’. cylindrica (loc. cit.), under the name of Ff. depressa, which latter species Dr. Geinitz (loc. cit.) recognizes from Upper Coal-Measure strata at Nebraska City, Nebraska. Meek and Hayden have proposed the name fF. ventricosa to include certain robust forms from the Coal-Measures of Missouri and Kansas (Proe. Acad. Nat. Sci. Phila., 1858, 261), and Mr. Meck has described two other species from a similar horizon in California under the names of F. robusta and I’. gracilis (Geological Survey of California, paleontology, vol. i, 1864). With due deference to the views of those able and careful paleontologists, I feel bound to differ with them in relation to the propriety of a specific separation of these forms. Long familiarity with this protean species, dis- tributed over an extensive region, has served to convince me that all the varieties referred to, including F. depressa Fischer, belong to one species only. In Southwestern Iowa, where Fusulina is abundant in strata of the Upper Coal-Measures, varieties prevail at certain localities respectively that
Sof
(F
98 CARBONIFEROUS PERIOD.
will answer the description of every imputed specific form of the genus yet known to me. Intermediate forms may also be obtained in the same region that may be made to connect all the varieties referred to. Remembering also that these shells were formed by animals, each of which consisted of a mere particle of organless sarcode, not having even the least differentiation of tissue, the wonder seems rather that intra-specific variation should not - be much greater than the difference is found to be between any individual shells hitherto referred to the genus Fusulina.
Position and locality—Strata of the Carboniferous period at the follow- ing localities in Utah, besides others elsewhere: Wasatch range, south of Spanish Fork; U-i-ya-bi Pass, Gosute range; near Beckwith Spring, Cedar range; near the mouth of Spanish Fork Cation; and southeast of Mount
Nebo. RADIATA.
CLAss ACTINOZOA. Orver ZOANTHARIA. Faminry FAVOSITID A.
Genus CHAETETES Fischer, 1837.
Cheetetes milleporaceus Troost, sp. Plate VI, fig. 2 a.
Calamapora milleporacea Troost, 1849? (manuscript). Chetetes milleporaceus Hdwards et Haime, 1851, Monographie Polyp. Fossiles, 272.
Polypary massive; cells slender, capilliform in aspect, of nearly equal size among themselves and of uniform diameter from their proximal to their distal ends ; diameter of cells about one-third of a millimeter, and upon the split surfaces of some specimens they have been traced continuously nearly the length of a decimeter; masses varying in size from four or five centi- meters to as many decimeters in diameter; shape of the masses irregularly globular to irregularly flattened-convex, the latter being the most usual form. Sometimes specimens, apparently of this species, are irregularly
CARBONIFEROUS PERIOD. 99
elongate in form, and show some indications of incipient branching; but the species is essentially a massive and not a branching coral.
This coral is not uncommon in the Upper Coal-Measures of Missouri, Towa, and Nebraska. The type-specimens of the species which were used by Edwards and Haime in their original description were obtained from Carboniferous strata in the Cumberland Mountains of Tennessee, and also from the same geological horizon near Evansville, Indiana. The late Dr. Troost had catalogued the species before his death, with the intention of publishing a description of it. In its subsequent publication by Edwards and Haime (Joc. cit.), they adopted his specific name.
Position and locality—Strata of the Carboniferous period; Virgin range, southwest of Saint George, Utah.
GENUS RHOMBIPORA Meek, 1872. Rhombipora lepidodendroides Meek.
Plate VI, fig. 5 a, b, c, and d. Rhombipora lepidodendroides Meek, 1872, United States Geol. Surv. Nebraska, 141.
Coral slender, ramose; stem and branches terete; branches not nu- merous, generally attaining at once nearly or quite the size of the stems: branching taking place at somewhat. regular intervals in some specimens, but irregularly in others, the divergence being some thirty or forty degrees ; stem and branches usually nearly or quite straight between the points of bifurcation, but neither the stem nor the branch above the point of bifurca- tion retain the axial direction of the part below; cells small; starting from a non-substantial axis they arch upward and outward, increasing a little in size as they extend, and open upon the outer surface; interspaces between the cells about equal in width to the diameter of the cells, the intercellular substance being itself minutely cellular in structure; cell-apertures rhombic or rhombic-oval in outline, the vertical diameter generally greatest; cells arranged in both vertical and oblique rows, which are always quite regular; spaces between the apertures ornamented with minute nodes, the largest ones of which are placed opposite the angles of the apertures, at which points there are sometimes two such nodes. Stems varying in diameter from one to four millimeters; number of cell-apertures five or six in the
100 CARBONIFEROUS PERIOD.
space of two millimeters, measured parallel with the axis of the stem, and seven or eight in the same space measured along one of the oblique rows. The variation of the latter measurements in different specimens is not proportionally so great as the variation of the diameter of stems, because the angle of the oblique rows with the axis is greater in large stems than in small ones; this gives the cell-apertures a greater proportional width in | large stems, while the actual width is nearly uniform in all.
Most of the examples in the collection are considerably larger than the type-specimens of Mr. Meek, but some of them agree perfectly with his types as to size, and the structure is identical in all, so far as can be determined. Specimens, apparently of this species, from the Upper Coal- Measures of Northern Missouri and Southern Iowa, are still larger than any contained in the collections. Some of the specimens of the collections are more or less completely silicified, and one or two of them have a hollow axis. This seems to have resulted from the failure of the central portion to become silicified like the outer portion, which, remaining calcareous, was subsequently removed by dissolving agencies that the outer silicified por- tion resisted. 'Thisis really shown to be the case by the breaking of others, and finding the central portion yet calcareous and retaining the structure of the coral, the parts of which structure being in direct continuity with those of the outer silicified portion. On the other hand, a fragment of a species of this genus obtained from the Subcarboniferous limestone of Washington County, Indiana, seems to have a hollow axis, the whole of the coral being calcareous. It is, however, not certain that the axis of even this example was originally hollow.
Position and locality—Strata of the Carboniferous period ; west face of Oquirrh range, near “Ki. T. City”, Utah, and at the confluence of White Mountain and Black Rivers, Arizona.
GENUS SYRINGOPORA Goldfuss, 1826. Syringopora multattenuata McChesney (?). From strata of the Carboniferous period, at various localities in Nevada and Utah, specimens of a species of Syringopora_were obtained. They are too imperfectly preserved for satisfactory specific identification,
CARBONIFEROUS PERIOD. 101
but they probably belong to S. mulattenuata McChesney, as they are not unlike that species and occupy a similar geological position. That species is a more or less common one in the Upper Coal-Measure strata of Iowa, Illinois, Missouri, and Nebraska.
Famity CYATHOPHYLLIDA. GENUS ZAPHRENTIS Rafinesque et Clifford. Zaphrentis excentrica Meek. Plate VI, fig. 3 a. Zaphrentis excentrica Meek, 1872, Geol. Surv. Montana, Idaho, Wyoming, and Utah, 495.
Corallum large, comparatively short, broadly turbinate, slight curved; principal septa sixty or seventy, not extending to the center of the calyx, but leaving a large plain surface at its bottom; tabulze numerous, broad, thin, transverse, or alittle concave; vesicular zone comparatively narrow. Height, about seven centimeters; breadth at top, about six centimeters.
Our specimens are silicified and somewhat imperfect, but they are doubtless specifically identical with Z. excentrica Meck, the type-specimens of which were obtained from strata of the same period at ‘“‘Old Baldy”, near Virginia City, Montana.
Position and locality.—Strata of the Carboniferous period; Fossil Hill, White Pine County, Nevada.
Genus LOPHOPHYLLUM Edwards et Haime, 1850. Dophophyliam proliferum McChesney, sp., var. sauridens. Plate VI, fig. 4 a, b, c, and d. Cyathaxonia prolifera McChesney, 1860, Descriptions of New Paleozoic Fossils, 75. Cyathaxonia, sp., Geinitz, 1866, Carbonformat. und Dyas in Nebraska, 65-66. Lophophyllum proliferum Meek, 1872, U.S. Geol. Surv. Nebraska, 144.
Corallum conical or elongate-conical, usually curved, rarely almost straight, tapering to a more or less slender point at its proximal end; trans- verse section circular; surface marked by longitudinal striz of uniform size, some of which are continuous from the apex to the rim of the calyx, but the additional strize required by the increasing diameter of the corallum are often so arranged as to form a kind of longitudinal suture by commenc- ing successively along the side of an outer stria of a series that are continu-
102 CARBONIFEROUS PERIOD.
ous from apex to calyx; longitudinal strize crossed by more or less distinct wrinkles, and very fine encircling lines of growth.
Calyx comparatively deep ; its sides rather thin between the septa, and of nearly uniform thickness from rim to bottom; rays within the calyces of the largest specimens sometimes reaching. fifty in number, not projecting far inward from the sides except toward and at the bottom, wpon which they reach the columella; bottom of the calyx really sloping downward from the columella all around, and ending abruptly against the sides, but the numerous septa, by gradually approaching the columella from the sides, give the bottom a concave appearance when viewed from above; septal fossette not very conspicuous, usually occupying a little more than the space of one principal body-ray, or septum; septa below the calyx, less numerous than the rays within it, well developed, and reaching nearly or quite to the columella, but none of them apparently becoming consolidated with it except the one opposite the septal fossette; columella strong, trans- verse section broadly oval, projecting considerably from the calyx, bluntly crested, well consolidated by the almost complete fusion of the middle por- tions of the tabule that compose it, not firmly united to the surrounding portions of the corallum, but readily cleaving from them when the parts are broken; when thus separated, its surface shows somewhat twisted, longi- tudinal, raised, striae which correspond more or less closely with the inner edges of the septa, but are not really separated parts of them, as they at first sight appear to be; tabulze comparatively thin, between the columella and the sides, sloping or arching downward, and ending abruptly against the inner side of the outer wall.
Length of the largest specimen in the collection, along its convex side, upward of four centimeters; diameter of the calyx, twelve millimeters. The average size of full-grown specimens is not materially less.
_ Our examples present a different aspect from typical forms of S. proli- Jerum, and they perhaps belong to a different species; yet it is difficult to point out distinct structural differences of specific value. They have, how- ever, a larger average size, and are more robust, less wrinkled, and less con- torted than typical forms of S. proliferum, which characters seem to indicate
at least a distinct variety, for which the name sauridens is proposed. ‘The
CARBONIFEROUS PERIOD. 103
prominent solid axis of that species, separating so readily from the surround- ing parts in broken specimens, caused it for a time to be referred to the genus Cyathaxonia, but Mr. Meek has shown (loc. cit.) that it has the internal structure of Lophophyllum.
Position and locality—Strata of the Carboniferous period ; near Santa Fé, New Mexico, and at Rock Creek, Lake County, Colorado.
Genus LITHOSTROTION Fleming, 1828 Lithostrotion Whitneyi Meek. Plate VI, fig. 1 a, b, and e. Lithostrotion Whitneyi Meek, 1875, Pal. of U. 8. Geol. Expl. 40th Parallel, (manuscript).
Corallum fasciculated; corallites cylindrical, somewhat flexuous and irregular, generally separate but seldom distant, and sometimes in contact ; epitheca thin but distinct, marked by wrinkles and encircling lines of erowth; columella small and very narrow, being laterally compressed ; principal rays from twenty to twenty-eight in number, according to the size of the polypite, alternating with smaller rays; tabulee numerous, com- paratively broad, transverse or arching downward from the columella ; vesicular zone narrow, composed of from three to five layers of vesicles.
Diameter of polypites, from eight to fourteen millimeters.
In splitting and polishing a polypite, so as to obtain a view of the internal structure, it is often difficult to make the section in such a manner as to show the columella, because it is so small and narrow. If the section is made parallel with one of its flat sides, but not cutting through it, the tabulze appear to be separate from each other in all parts, and to extend directly across the polypite, as in Cyathophyllum. Such a section is shown in figure 1 ¢, Plate VI. If the section passes obliquely through the columella, its character is indistinctly shown, as in figure 1 b of the same plate. The section given by Mr. Meek in his illustrations of the species is through the short diameter of the columella.
Position and locality—Strata of the Carboniferous period; Fossil Hill and Ice Creek, Steptoe Valley, White Pine County, Nevada.
104 CARBONIFEROUS PERIOD.
Ciass ECHINODERMATA. Orper ECHINOIDEA.
Famity ARCHAOCIDARIDA. GENnus ARCHASOCIDARIS McCoy, 1844. Archeocidaris ornatus Newberry. Plate VI, fig. 7.
Archeocidaris ornatus Newberry, 1861, Geol. Rep. Lieut. Ives’s Expl. Col. Riv., 116.
Principal spines fusiform, strong, about seven centimeters long; great- est diameter a little below the middle, where it is about five millimeters; surface for a short distance above the basal ring plain or not conspicuously marked; above this plain space to the distal end, it is thickly set with spin- ules from one to two millimeters in length, which are arranged around the spine in imperfectly spiral lines, in which lines the intervals between the spinules are generally less than the diameter of their bases, but the vertical intervals are somewhat greater; basal ring rather large, crenulated at the border. An imperfect interambulacral plate embedded in the rock near one of the spines contained in the collection, and probably belonging to this species, shows a plain areolar surface, a raised center, and an elevated rim around a rather small central tubercle. Remainder of the body unknown,
Dr. Newberry’s type-specimens were obtained from strata of the Car- boniferous period near the confluence of the two Colorados, and also from strata of the same period near the Great Canton of the Colorado River. _
Position and locality—Strata of the Carboniferous period; ten miles west of Ojo del Oso, near Fort Wingate, New Mexico.
Archeocidaris trudifer White. Plate VI, fig. 8 a and b.
Archeocidaris trudifer White, 1874, Exp. & Surv. west 100th Merid., Prelim.’Rep. Invert. Foss., 17.
Interambulacral plates comparatively broad, rather thin, having an elevated border all around, which is apparently composed of a series of small tubercles; areolar surface apparently plain; central tubercle small, perforate at the center, surrounded at its base by a very slightly-raised ring, ~
CARBONIFEROUS PERIOD. 105
and immediately outside of that by another ring, which is so much elevated as to form a little cup, with its rim somewhat expanded. Diameter of. the largest plate in the collection, about twenty millimeters.
Spines very long and slender, one of those in the collection having been, when perfect, about twelve centimeters in length, terete; diameter of the basal ring, which expands abruptly from the shaft, greater than that of any portion of the shaft; diameter of the shaft nearly uniform for more than half its length above the basal rmg, the upper portion gradually taper- ing to a point. Greatest diametey of the shaft of the long spine referred to, scarcely five millimeters; diameter of the basal ring, seven millimeters. Surface of the spine for a short distance above the basal ring apparently smooth, but, from that portion to the distal end, it is ornamented with numerous small points or incipient spinules, which are often removed by weathering, but, in well-preserved specimens, they are seen to be arranged around the spine in imperfectly spiral lines. -
The very long, slender, terete spine, having a basal ring often much greater in diameter than any part of the shaft, together with the other characters described, distinguish this species from all others.
Position and locality—Strata of the Carboniferous period (“Red Wall | limestone”); Camp Apache, Arizona.
MOLLUSCA.
MOLLUSOIDEA.
CLASS POLYZOA. Orpen GYMNOLAIMATA.
_Famity MYRIAPORIDA. GENUS GLAUCONOME Goldfuss, 1826. Glauconome nereidis White. Plate VII, fig. 5 a, b, ¢, d, and e.
Glauconome nereidis White, 1874, Exp. & Surv. west 100th Merid., Prelim. Rep. Invert. Foss., 18.
Polyzoary branching, the main stem sending off branches at irregular intervals; these in like manner sending off secondary branches, but less
106 CARBONIFEROUS PERIOD.
frequently; the stem and all the branches bearing branchlets of the usual character, in regular series at each side, all of which are straight or slightly curved; branches leaving the stem, and branchlets the stem and branches, at nearly or quite uniform angles of between sixty and seventy degrees; branch- lets opposite, or alternating in their arrangement, the intervals between them being a little greater than the diameter of the branchlets; non-poriferous side of the stem, branches, and branchlets all convex and marked by fine longitudinal striz. Poriferous side of the stem and branches bearing a row of pores along each of their lateral borders, the number of pores being about twice as great as that of the branchlets, but they are not placed in perfectly regular order with them. The space between these two lateral rows of pores is convex, and marked by scattered dimorphous pores that are not more than half as large as the principal ones which form the lateral rows. Branchlets also bearing a row of pores at each lateral border of the poriterous side, which are of the same character as the principal pores of the stem and branches, but they average a trifle smaller than those; pore- apertures with a rather prominent border, which gives the branchlets a somewhat knotted appearance under a lens.
There is considerable difference in the size of the broken stems and branches which constitute the specimens of the collection ; but none of them, not even the longest fragment, perceptibly diminishes in size toward the dastal end. The largest stem is about half a millimeter in diameter and the smallest not more than half that size. The branchlets vary from one to three millimeters in length. The whole extent of the branching of a polyzoary of this species is unknown; but, as the branches are only exces- sively developed branchlets, there seems to be no necessary restriction in this regard, but, in fact, the branching seems to have been somewhat limited. When one of the branchlets reached a little greater length than its fellows adjacent, it sent off branchlets from its own sides and became a branch. Ina few cases, these first branchlets of the newly-formed branch have been seen to coalesce with adjacent branchlets of the stem, thus forming a few irregu- lar fenestrules.
This species differs from G. triliniata Meek, from strata of the same period in Nebraska, in being much branched, and especially in the presence
CARBONIFEROUS PERIOD. 107
of minute, dimorphous pores upon the axial portion of the poriferous side of the stem and branches, and also in the absence of the three longitudinal raised lines that distinguish that species.
Position and locality—Strata of the Carboniferous period; at the con- fluence of White Mountain and Black Rivers, Arizona.
GENUS SYNOCLADIA King, 1849.
Synocladia biserialis Swallow. Plate VII, fig. 3 a, b, and c. Synocladia biserialis Swallow and Hawn, 1858, Trans. Acad. Sci. St. Louis. 1, 179. Synocladia virgulacea Geinitz, 1866, Carbonformat. und Dyas in Nebraska, 70. Synocladia biserialis Meek, 1872, U. 8. Geol. Surv. Nebraska, 156.
Polyzoary probably infundibuliform, but the specimens usually found consist only of spreading frond-like fragments; primary branches a. little larger than the others, the latter increasing by divergence at various angles from the primary branches, also occasionally from each other, and rarely by starting upward from the middle of a dissepiment; dissepiments cellu- liferous, a little narrower than the branches, and arching upward a little as they extend from branch to branch; fenestrules irregularly four-sided ; upper side usually convex, and lower side sometimes concave, about nine in the length of a centimeter, measuring upward, generally wider than the branches, but occasionally narrower, especially near the base of the poly- zeary. Upon the poriferous side, the branches and dissepiments, especially the former, are each provided with an irregular mesial carina, consisting of small, elongate, confluent nodes, which are sometimes sharp and prominent. Cell-apertures moderately large, rounded, borders prominent; cells arranged in single, quite distinct lines, one on each side of the mesial carina of the branches, and generally each dissepiment bears a double row of similar cells. Upon some of the dissepiments the cells form only a single row at the middle, while upon others they are not only double but another cell is added near the junction with the branch, giving three cells abreast at those points.
Professor Geinitz and others have referred this species to S. virgulacea as only varietally different from the typical forms of -that species. 8.
108 CARBONIFEROUS PERIOD.
biserialis is now known to extend over an area more than one thousand miles across in a direct line, throughout the whole extent of which it is sur- prisingly constant in its specific characters, and just as constantly different from those of S. virgulacea as that species is represented by the figures and descriptions of European authors. The European species is without the mesial carina of ours, but has in its place a median row of pores, which our species never has.
Position and locality—Strata of the Carboniferous period (Red Wall limestone) ; Camp Apache, Maricopa County, Arizona.
GENus POLYPORA McCoy, 1844. Polypora stragula White. Plate VII, fig. 4 a and b.
Polypora biarmica Geinitz, 1866, Carbonformat. und Dyas in Nebraska, 68 (not P. biarmica Keyserling).
Polypora (species undetermined) Meek, 1872, U. 8S. Geol. Surv. Nebraska, 155.
Polypora stragula White, 1874, Exp. & Sury. west 100th Merid., Prelim. Rep. Invert. Foss., 19.
Polyzoary apparently flabelliform; longitudinal branches bifureating with more or less irregularity in different parts of the polyzoary; dissepi- ments little if any more than half as wide asthe branches; fenestrules oval or oblong, the porportions of length and width varying in different parts of the polyzoary from about one-quarter longer than wide to twice as long as wide; varying also in size in different parts of the polyzoary, but averaging about six in number within the length of a centimeter, measured longitudi- nally ;