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DEPARTMENT OF THE INTERIOR. 



R K P» ( ) R T 




CSITED STATES GEOLOGICAL SURVEY 



THE TERRITORIES. 



F. V. H-AYDEN, 

UNITED STATES GEOLOGIST-IN-CHAUGE. 



IN FIVE VOLUMES. 



WASHINGTON: 

GOVERNMENT PRINTING OFFICE. 
1873. 



LETTER TO THE SECRETARY. 

Sir: 1 have the honor to jircsent for your approval and for publication the 
tirst part of volume I of the quarto series of reports which are intended to 
embody the more original and technical results of the survey under my direc- 
tion. Tlie present memoir on the " Extinct vertebrata of our Western Terri- 
tories" has Ijeen elaborated by Professor Joseph Leidy, the eminent compar- 
ative anatomist, and will form one of the most important contributions to the 
science of extinct organisms ever made in this country. This memoir will 
be followed b}' a second part on the same subject by Professor E. D. Cope. 

Volume II will embrace the subject of the extinct flora of our western 
Territories ; and it is the purpose to make it as exhaustive as possible. Pro- 
fessor J. S. Newl)erry is preparing the first part and Professor Leo Lesque- 
reux the second. The well-known reputation of these gentlemen is a suffi- 
cient guarantee for the value of their work. 

Volume III will include all the materials collected by the survey ou the 
subject of extinct invertebrata, and will be most carefully elaborated by the 
eminent j)aleontologist of the survey, Mr. F. B. Meek. 

Volume IV will embrace the profiles, sections, maps, and other illustrations, 
with descriptive text by the geologist in charge. 

Volume V will contain separate memoirs on different subjects in recent 
zoology and botany, prepared by several authors. All the new and imper- 
fectly described species of plants or animals collected by the survey will be 
studied and fully illustrated. All these volumes are now in an advanced state 
of preparation. In presenting to the world these important contributions to 
science, permit me, sir, to extend to you my sincere thanks for your intelH- 
gent sym]iathy and hearty co-operation in the work. 
Very respectfully, your obedient servant, 

F. V. HAYDEN, 
United States Geoloff,ht. 

Hon. C. Delano, Scrrctarji of the Ii/fcrior. 



^f 



"V^OLXJME I. 



FOSSIL VERTEBRATES 



P^RT 1 



CONTRIBUTIONS 



EXTINCT VERTEBRATE EAUNA 



THE WESTERN TERRITORIES. 



liV 



PROF. JOSEPH LEIDY. 




TABLE OF CONTENTS. 



Pafie. 

PREFACE 14 

EXTINCT VERTEBRATE FAUNA OF THE BRIDGER TERTIARY FORMATION OF WYOM- 
ING TERRITORY 15 

INTRODUCTION 15 

MAMMALIA 27 

Oider PcrissodactyJa 27 

PalsBosyops - 27 

paludosua 28 

major 45 

Junius 57 

Lininoliy us 57 

Hyrachy us 51( 

agrarius (iO 

exiaiius OG 

modestus 07 

nanus fi7 

Lopliiotberium <i'J 

sylvaticum : G9 

Trogosus • 71 

castorifleus 71 

vetulus 75 

Hyopsodas 75 

paulus 75 

niinuscnlus 81 

Microsus HI 

cnspidatus 81 

Myciosy ops 82 

gracilis 83 

Nothaictus 86 

tenebrosus 86 

Hipposy us 90 

formosus 90 

robustior 93 

Order Prohoscidea 93 

Uintatberium 93 

robustum 96 

Order iJo(?(;H(ia 109 

Paraniys 109 

delicatus -. 110 

delieatior 110 

delicatissimus Ill 

Mysops I'l 

minimus Ill 

fraternus 11- 

Soiuravus 113 

Order Carnirora Ill 

Patrioft-lis 114 

ulta 114 

Sinopa : 11<5 

ra]ias 116 

eximia ■■ 1^^ 



;/;^ 



H CONTENTS. 

MAMMALIA— Coutiniu'd. 

Order Carinvora. Page. 

Uiutaoyon 118 

eclax 118 

voras V.>0 

Order Iiiscct'ivora • \->Q 

Oiiiomys '. li>0 

Carter! 120 

Palaaacodon 122 

veriTs 122 

Wasbakius ■ 123 

iusiguis 123 

Elotboriiiiii 124 

EEPTILIA 125 

Order CrocodiUa 125 

Crocodilus ' 125 

aptus 126 

Elliotti 12G 

Order Chi-lonia .• 132 

Testudo 132 

Corsoni '. 132 

Emys 140 

•vvyomingensis 140 

Bapteniys 154 

wyoraingensis 157 

Baena 160 

arenoaa ' Kil 

Cbisteruoii 169 

undatam 1G9 

Hybemys 174 

arenariiia 174 

Auosteira 174 

oruata 174 

Trionyx 176 

guttatus 176 

uintaeusis 178 

Remains of Trionyx of undetermined species 180 

Order LaccrllUa 180 

Sani wa 181 

ensidens 181 

major 182 

Gly ptosaurus 182 

Cbameleo 184 

pristinus - 184 

FISHES 184 

Amia (Protamia) uiutaensis 185 

media 188 

gracilis 188 

Hypaniia 189 

elegans 189 

Lepidosteus 189 

atrox 189 

(?) 190 

simplex 191 

notabilis 192 

Pimelodus 193 

antiquus - 193 

Pbareodus 193 

acutus 193 



CONTENTS. *J 

FISHES— ContiiiMcil. Page. 

REMAINS OF FISHES FROM THE SHALES OF GREEN RIVER, WYOMING m 

C'lnpea 195 

huiuilis 195 

alta 1% 

DESCRIPTION OF REMAINS OF MAMMALS FROM THE TERTIARY FORMATION OF 

SWEETWATER RIVER, Vv'YOMING 198 

MAMMALIA 199 

Order Itumhiaiitia 199 

Jleiycoehcerus 199 

rusticus 199 

sp. (?) 208 

Order Sorulmujii!" ■■■■ 208 

DESCRIPTION OF VERTEBRATE FOSSILS FEOxM THE TERTIARY FORMATION OF 

JOHN DAY'S RIVER, OREGON 210 

MAMMALIA 211 

Order liiiminaiitia 211 

Oreodon 211 

Culbertsoui 211 

superbus 211 

Leptomeryx 21(j 

E vansi 210 

AgriocbcBrus 216 

autiqiius 210 

latifrous , 216 

Order Ariiodactijla _ 210 

Dicotyles 216 

pristiuus 216 

Elotberium 217 

imperator 217 

Order Solidungula „ 218 

Ancbitherium 218 

Bairdi 218 

Condoui 218 

Order Pcrissodactyla 219 

Lopbiodou 219 

Rhinoceros 220 

besperius 220 

pacificus 221 

Hadrobyiis 222 

supremus 222 

An luidetermiued carnivore 223 

CHELONIA 223 

Styletiiys 223 

uebrascensis 224 

niobrarensis 225 

oregouensis ' 226 

DESCRIPTION OF REMAINS OF VERTEBRATA FROM TERTIARY FORMATIONS OF 

DIFFERENT STATES AND TERRITORIES WEST OF THE MISSISSIPPI RIVER 227 

MAMMALIA 227 

Order Carnivora 227 

Felis 227 

augustus 227 

imperialis 228 

Canis 230 

indianeusis 2:;0 

Order Proboscidea 231 

Mastodon 231 

obscurus 231 

mirificus 237 

iimericanus 237 

II — U 



10 CONTENTS. 

MAMMALIA— Coutinuoil. 

Order Prohoscidca. Pa^o. 

Elephas 03^ 

americauus o^^ 

Megacerops 239 

coloradensis 239 

Order SoUdungula 242 

Equus 242 

occidentalia 242 

major 244 

Hippariou 247 

Prof ohiiipus s. Merychippus 248 

Auchitherium 250 

australe 250 

agreste 251 

(?) 252 

Order Ruminantia 253 

Bisou 253 

latifrous _. 253 

AucUenia 255 

hesterna 255 

Procamelus 258 

virginiensis 259 

Megalomerys 2()0 

niobrarensis 230 

CHELONIA 260 

Emys 260 

petrolei 260 

FISHES 201 

Family Ci/prinida; 262 

Mylocyprinus 262 

robustus 262 

Family Eaice 264 

Oncobatis 264 

pentagouus 264 

DESCRIPTION OF REMAINS OF REPTILES AND FISHES FROM THE CRETACEOUS 

FORMATION OF THE INTERIOR OF THE UNITED STATES 266 

REPTILES 267 

Order Dinonaurla 267 

PoicilopleuroQ 267 

valena 267 

Order Chdonia 269 

Order Mosusauria 270 

Tylosaurus 271 

dyspelor 271 

proriger 271 

Lcstosaurns 276 

coryphiBus 276 

Mosasaurua 279 

Clidastes 281 

iutermedius 281 

affiuis 283 

Order Lacertilia 285 

Tylostens 285 

ornat ns 285 

Order Sauroj)tcrijfjia 286 

Oligosimus 286 

graudajvus 286 

Nothosaurus 287 

occiduna 287 

FISHES 288 

Teleostei 288 



CONTENTS. ] 1^ 

FISHES— Continued. Pago 

Order Acanthoptai 288 

Spliyrajnidao 288 

Cladocyclus 288 

occidentalis 288 

Enchodns 289 

Shuniardi 289 

Phasganodus 289 

dirns : 289 

Older Malacopteri 291 

Silurida) 991 

XiiJhaotinus : 291 

audax . 291 

Ganoidei 292 

Pycuodus 292 

faba 292 

Hadrodus 294 

prisons 295 

Elasiiobi:axciiii 295 

Order Plagiostomi 295 

Ptychodus Mortoui 295 

occidentalis 298 

Whippleyi 300 

Acrodns :500 

humilis 300 

Galeocerdo 301 

falcatns 301 

Oxyrhina 302 

extenta 302 

Lamna s. Oxy rbiua 303 

Otodus 305 

divaricatus 305 

Order Holocephali 306 

.Edaphodon 306 

mirificus 306 

Eumylodus 309 

laqneatns 309 

NOTICE OF SOME REMAINS OF FISHES FROM THE CARBONIFEROUS FORMATION OF 

KANSAS 311 

Order Plagiostomi 31] 

Cladodus 311 

occidentalis 311 

Xystracanthus 312 

arcuatns 312 

Pctalodus 312 

alleghauiensis 312 

Asteracanthus . 313 

siderius 313 

SYNOPSIS OF THE EXTINCT VERTEBRATA DESCRIBED OR NOTICED IN THE PRESENT 

WORK : 315 



Philadelphia, January 13, 1873. 
Dear Sir: Herewith I transmit to you my report on vertebrate fossils from 
the Western Territories and States. Many of the specimens were collected 
during your geological explorations, and were submitted to me for investiga- 
tion. Others have been collected by different persons living in the West, 
and sent to me directly, or through the agency of the Smithsonian Institution, 
for examination. Most of the fossils were obtained in Wyoming, and the 
others were derived from Oregon, California, New Mexico, Idaho, Colorado, 
Kansas, and Nebraska. 

With respect, I remain, at your service, 

JOSEPH LEIDY. 
Professor F. V. Hayden, 



United States Geologist.- 



2 G 



PREFACE. 



The present work was commenced in 1870, at which time the amonnt of 
materials as subjects of investigation and description was comparatively small. 
A constant accession of new materials, beyond all anticipation, has greatly 
extended the work. This will account for the apparent want of system in 
the arrangement or proper collocation of the subjects of many of the plates. 

The interest excited by the numerous discoveries of vertebrate fossils in 
the Western States and Territories has led to the recent explorations of Pro- 
fessors Marsh and Cope, both of whom have obtained rich collections. The 
investigations and descriptions, by these gentlemen, of some of the fossils 
from the same localities, have been so nearly contemporary with my own, that, 
from want of the opportunity of comparison of specimens, we have no doubt 
in some cases described the same things under different names, and thus pro- 
duced some confusion, which can only be corrected in future. 

My investigations, in many instances, may appear not so complete as would 
be desirable, and my excuse for not doing the work more thoroughly is the 
limited time allowed for the purpose and the little leisure I have had in the 
intervals of other and necessary professional engagements. 



EXTINCT VERTEBRATE FAUNA OF THE BRIDGER TERTIARY 
FORMATION OF WYOMING TERRITORY. 



INTRODUCTION. 



The following pages contain a liescrijjtion of foysil remains of vertebrated 
animals collected in the vicinity of Fort Bridger, a military post situated in 
the southwest corner of Wyoming Territory. 

Many of the specimens were obtained during Professor Hayden's geological 
explorations of 1869 and 1870, but the greater part of them were collected 
during the same years and the succeeding one by Dr. James Van A. Carter, 
residing at Fort Bridger, and by Dr. Joseph K. Corson, United States Army, 
the surgeon of the post. These gentlemen have diligently explored a wide 
extent of country in their immediate neighborhood in the search for fossils 
with the most intelligent interest. The results of their explorations they 
h:ive liberally placed at the service of naturalists by voluntarily donating 
all the more characteristic portions of their collections to the Academy of 
Natural Sciences of Philadelphia.* 

After the present work was supposed to be nearly ready for the press, and 
the accompanying plates from I to XXII were complete, the last summer, the 
writer received a pressing invitation from his friend Dr. Carter to visit him 
at Fort Bridger. As the invitation was accompanied with liberal facilities 
and offers of aid in exploration, the author availed himself of the opportunity 
of visiting a region of so .much interest, and accordingly spent the summer 
vacation in a trip to the locality. 

Fort Bridger occupies a situation in the midst of a wide plain at the base of 
the Uintah Mountains, and at an altitude of nearly seven thousand feet above 
the ocean-level. The neighboring country, extending from the Uintah and 
Wahsatch Mountains on the south and west to the Wind River Range on the 
northeast, at the close of the Cretaceous epoch, appears to have been occupied 

* In speakiug of this institutiou hereafter I shall briefly refer to It as the Academy, 
or the Academy of Phihulelphia. 



16 

by a vast fresh-water lake. Abundance of evidence is found to prove that 
the region was then inhabited by animals as numerous and varied as those of 
any other fauna, recent or extinct, in other parts of the world. Then, too, a 
rich tropical vegetation covered the country, in strange contrast to its present 
almost lifeless and desert condition. 

The country appears to have undergone slow and gradual elevation ; and 
the great Uintah lake, as we may designate it, was emptied, apparently in suc- 
cessive portions and after long intervals, initil finally it was drained to the 
bottom. 

The ancient lake-deposits now form the basis of the country, and appear 
as extensive plains, which have been subjected to a great amount of erosion, 
resulting in the production of deep valleys and wide basins, traversed by 
Green River and its tributaries, which have their sources in the mountain 
boundaries. From the valley of Green River the flat-topped hills rise in suc- 
cession as a series of broad table-lands or terraces, extending to the flanks of 
the surrounding mountains. 

The snows of the Uintah, Wahsateh, and other mountain-ranges are a 
never-failing source to the principal streams ; but many of the lesser 
branches, dependent for their supply on the accumulated snows of winter in 
ravines of the lower hills and plains, completely dry up as the snows disap- 
pear with the approach and advance of summer. The country for the most 
part is treeless and destitute even of large shrubs, excepting along some of 
the water-courses. The principal streams are fringed with trees, consisting of 
cotton-wood {Populus angustifolia) and willow, (Salix longifoUa ;) and the 
valleys through which they run produce mostly rushes (Juncus baltlcus) and 
sedges, with some coarse grasses, as Eli/ in us condensatus and Triticum repens. 
Hollows of the liills and narrow valleys, favorable to the retention of moisture, 
support foi'ests of small aspens, {Fopulus tremuloides.) The higher terraces 
and foot-hills approaching the mountain-ranges are covered with dense forests 
of aspens, pines, {Pinus ponderosa and P. fle.rUis,) and firs, (Abies Menziesil, 
A. Engelmanni, A. grandis, SjC.,~) with a rich undergrowth of herbaceous 
plants. The great mountains themselves present a broad belt of pines and 
firs, from which project the rocky sunrmits as bare of vegetation as the wide 
plains at their l)ase. Many of the lower hill-sides and hollows in certain 
situations are sparsely covered with cedars, (Juniperus virginiana,) most of 



17 

which are very okl in appearance and remarkably distorted, twisted, and 
broken. 

The principal growth of the plains consists of sage-l>ushes {Arteiiiesia tri- 
dentatii) curiously distorted and split, so as to I'eniind one of the cedars just 
mentioned. In some places the sage-bushes are mingled witii or replaced I>y 
the gi-ease-wood, {Sarcobatus vermiculatus.) Wide, bare, path-like intervals 
surround the bushes, or the spaces are occupied by scanty grass, which 
formerly furnished food to the buffalo, now become extinct in this region 
and elsewhere west of the Rocky Mountains.* 

The fossils which form the subjects of our communication for the most 
part were derived from tire more superficial deposits of the great Uintah basin, 
which Professor Hayden has distinguished as the Bridger group of beds. 
These compose the terraces or table-lands in the neighborhood of Fort 
Bridger, and consist of nearly horizontal strata of variously colored indurated 
clays and sandstones. As the beds wear away, through atmospheric agencies, 
on the naked declivities of the flat-topped hills, the fossils become exposed to 
view and tumble down to the base of. the hills among the crumbling debris 
of the beds. 

The flat-topped hills or terraces of the Bridger basin, rising from Ijroad 
valleys and extended plains, form the most conspicuous objects of the land- 
scape. A similar condition of the country, alternating with boundless plains 
and great mountain heights, forms a charactei'istic feature of a great part ol 
the region west of the Mississippi. 

The flat-topped hills, table-lands, bench-lands, or terraces, as they are 
variously named, seen from lower levels, are usually called "buttes," especially 
when they are of limited extent. The name is of French origin, and signifies 
a bank of earth or rising ground. The name is likewise applied in a more 
restricted sense to the prominent irregularities of the deeply eroded and 
naked declivities of the more extended terraces. The buttes therefore vary 
in extent from a mere mound rising slightly above the level of the plains to 

* It has already become a question whether the buffalo existed west of the Eocky 
Mountains at a couiparativelj' recent period. That it did so was amply proved to the 
writer from his having noticed rem.ains of the animal in a number of places, from ravines 
skirting the Union Paciiic liailroad to the forests high up in the foothills of the Uintali 
Mountains. Judge W. A. Garter, of Fort Bridger, informs us that some of the old trap- 
pers iuid hunters of the district had told him that in their early days they had seen the 
buffalo in abundance in that country. 



18 

hills of varied configuration reaching to the level ol' the broarler buttes or ter- 
I'aces. In the course of ages the wearing away of these has been enormous 
and still continues under the usual atmospheric agencies, while the detritus 
is spread out on the plains below. 

From the lower plains the neighboring terraces, when of circumscribed 
extent, appear like vast earth- work fortifications, and when evenly preserved on 
the declivities for a considerable distance remind one of long railway embank- 
ments. Frequently the terraces are so extensively eroded and traversed by 
nai'row ravines that they appear as great groups of naked buttes rising from 
the midst of the plain, or assembled around the horizon closely facing and 
flanking the more distant and extended lands as if to protect them. Nothing 
can be more desolate in appearance than some of these vast assemblages of 
crumbling buttes, destitute of vegetation and traversed by ravines, in which 
the water-courses in midsummer are almost all completely dried. To these 
assemblages of naked buttes, often worn into castellated and fantastic forms, 
and extending through miles and miles of territory, the" early Canadian 
voyageurs gave the name of "Mauvaises Terras'' They occur in many local- 
ities of the Tertiary formations west of the Mississippi River. 

In wandering through the "Mauvaises Torres,'' or "Bad Lands,'' it requires 
but little stretch of the imagination to think oneself in the streets of some 
vast ruined and deserted city. No scene ever impresed the writer more 
strongly than the view of one of these Bad Lands. In company with his 
friends, Drs. Carter and Corson, he made an expedition in search of fossils 
to Dry Creek Cation,* about forty miles to the southeast of Fort Bridger. 
The canon, or valley, is bounded by high buttes, and contains a meadow of 
rushes, traversed by a stream which is liable to be dried up in the latter part 
of the summer, whence the name of the canon. On ascending the butte to the 
east of our camp, I found before me another valley, a treeless barren jilain, 
prol)ably ten miles in width. From the far side of this valley butte after 
butte arose and grouped themselves along the horizon, and looked together 
in the distance like the huge fortified city of a giant race. The utter desola- 
tion of the scene, the dried-up water-courses, the absence of any moving 

* The same uame is so frequently applied to difierent places as to lead to consider- 
able coufiision. When I speak of Dry Creek Caiion, I refer to a locality forty miles 
from Fort Bridger; and when Dry Creek is named, it refers to another locality ten miles 
from Fort Bridger. 



If) 

ohjfcl, and the profound silence wliicli prevailed, produced a ieeling tluit was 
positively oppressive. When I tlien thought of the buttes beneath my feet, 
widi their entombed remains of multitudes of animals forever extinct, and 
reflected upon the time wlieu the country teemed with life, I truly felt that 
I was standing on the wreck of a former world. 

The buttes are often specially designated from some supposed resemblance, 
or other character, as Church Butte, Pilot Butte, Grizzly Butte,* &c. 

As before intimated,, the more superficial table-lands of the Bridger basin, 
as they appear in the vicinity of Fort Bridger, are composed of nearly hori- 
zontal strata of various colored indurated clays and sandstones. In most 
localities visited by the writer the clays predominate, and are usually greenish, 
grayish ash-colored, and brownish. When unexposed they arc compact, 
homogeneous, and of stony hardness. In composition they vary from nearly- 
pure clay to si*ch as are highly arenaceous, and gradate into those in whicli 
sand largely predominates, and they usually contain few or no pebbles. They 
appear to be more or less fissnred, and break with an irregular and some- 
what conchoidal fracture. Exposed to atmospheric agencies, moisture, and 
frosts, they readily disintegrate, and the declivities of the buttes, generally 
entirely destitute of vegetation, are usually invested with crumbling material 
from a few inches to a foot or more in depth. When this loose material is 
wet it forms tenacious mud, and along the course of streams in the ravines, 
the deepest and most treacherous mire. Baked by the sun upon the plains, 
it fixes the drift-pebbles and other stones as firmly almost as if imbedded in 
mortar. 

In some localities the clays of the buttes abound in fresh-water shells, as 
Unio, Melania, Planorbis, &c. Less frequently in other places they con- 
tain land-shells, as Helix, &c. 

The sandstones are more frequently of various shades of green, but are 
also yellowish and pass into shades of brown. They are compact and hard 
when unexposed to the weather, and are usually fine-grained, but also occur 

*This name is applied to an extensive chain of buttes about ten miles to the south- 
east of Fort Bridger. Judge Carter informed me that the name originated from the 
circumstance that an old trapper, Jack llobinsou, once reported that he had found a 
])ctrilied grizzly bear on the Butte. From. the description of the petrifaction 1 have 
no doubt it was that of the animal 1 have named in the succeeding pages, Paheosyops, 
the skull of which resembles that of a bear. 



20 

of a gravelly coiLslitiilion. They arc fissured in comparatively large masses, 
wliicli assume a rounded lorm as lliey are worn away, so that a ledge of 
sandstone projecting from the declivity of a Ijutte will appear like a row of 
cotton Itales. As they disintegrate less rapidly than the contiguous clays, 
masses are olten ol)served resting upon cones and columns of the latter, con- 
triljuting greatly to the picturesque and sometimes fantastic appearance of 
the l)uttes. 

Many of the table-lands and lesser buttes in the vicinity of the Uintah 
Mountains are thickly covered with drift from the latter, consisting of gravel 
and bowlders of red and gray compact sandstones or quartzites. The drift 
material is usually firmly imbedded in the surface of the plains so as to 
appear like a pavement. The bowlders are generally small, but assume larger 
proportions approaching the Uintahs. In many cases the drift completely 
covers the terraces or buttes, descending upon the declivities s© as entirely to 
conceal their structure. Usually, however, it accumulates in the ravines of 
the declivities, leaving bare the intervening ridges of light-colored clays and 
sandstones. Many of the buttes are nearly or quite free of drift material. 
Some, again, are strewn with fragments of rock, consisting of tlie harder materials 
from the terraces themselves, and these likewise occur mingled with the 
drift-pebbles and bowlders from the mountain-heights. 

The stone-fragments from the buttes consist of harder siliceous and cal- 
careous clays, impure limestones, jaspers, and less frequently agate and chalce- 
dony. In some instances they consist of singularly black incrusted and 
niinided sandstones, somewhat of the character of scptaria. Specimens ot 
these occasionally !;)ear a resend:)lance to fossil turtles, and when found wWh 
I he harder crust broken tluy look like turtle-shells filled with a sandstone 
matri.x. 

In the buttes in the vicinity of Carter Station, on tiie Union Pacific Rail- 
road, I observed many large nodular and cylindroid masses of agate. These 
have a concentric arrangement of layers resembling that of fossil wood, for 
which they arc, taken. Many of the masses contain a nucleus of amber- 
colored crystals of calcitc. 

Nodules of chalcedony wilh dendritic markings occur in some of the 
buttes. These, together with the condition of many of the fossils of the 
buttes, indicate the presence of a considerable proportion of soluble silica in 



21 

the waters of tlie ancient lake. In sonic ol' tlie sandstones, the fossil shells 
have had their lime completely replaced by clear chalcedony.* 

Occasionally strata of limestone, mostly impure from the admixinre of elay 
and sand, arc found in some of the buttes. A frequent constituent also is 
tiltrous arragonitc, or satin-spar, in tliin seams. Many of the bare mounds of 
clay among the buttes are thickly strewn with fragments of this arragonite. 

The stones imbedded in the surface of the plains and Inittes, in some 
positions favorable for the purpose, are highly polished from the conjoined 
action of the wind and sand, and when seen in the slanting light of the early 
morning or evening sun, appear like myriads of scattered mirrors. In many 
positions, the stones, no matter what may be their composition, are all black- 
ened. The phenomenon I could not explain. 

In many places the stone-fragraents from the declivities of the terraces, 
strewn over the lower buttes or distributed over the plains, are splintered or 
flaked in a remarkable manner. The jaspers esi^ecially are often broken in 
such a way that they appear as spawls from rude implements of art, or even 
resemble the latter. Some of them are certainly the work of primitive man, 
I)ut the vast proportion, often scattered over miles of surface, are probal)ly 
accidental forms.* These I suppose to have been produced by stones striking 
one another in the descent from declivities as they have been carried down, 
perhaps by glacial movement. The softer rocks of the buttes, those which 
are too soft for stone works of art, are also observed broken in the same way 
as the hard ones. In experimenting on some large splintered slabs of jasper 
from the buttes of Dry Creek Canon, I found that a quick blow of a hammer 
would send off, with a ringing sound, a long sharp flake, reminding me of the 
primitive knives or scra])ers of the stone age of man. 

Between the well-finished implement and the accidental spawl every gra- 
dation of form may be observed among the scattered stones of the plains and 

* Perhaps much of this soluble silica may have been supplied by hot springs still so 
frequent in Wyoming and other Western Territories. Cold springs, slightly alkaline, 
may have also coutributcd to the petrifying silica. In Pioneer Hollow, flfteen miles 
west of Fort Bridger, I observed a dozen springs within the distance of a mile, tiie 
water of which reminded me of the congress- water of Saratoga, New York. It is cool 
and clear, highly carbonated, slightly alkaline, and agreeable to the taste. The springs 
are circular, from 1 to 15 feet across, and are surrounded with dome-like craters from 
1 to 3 feet high. The craters are formed of a siliceous sinter, which has been slowly 
deposited from the spring- water, and is probably the accuniulation of ages, The sinter 
is brown from the presence of iron, though the water has no perceptibly ferruginous 
appearance or taste. 



22 

Ijiittes. The accompanying- figures, from 1 to 12, represent some of the 
Haked stones, most of which, and perhaps all, are rude works of art. 

Many of the accidental forms, as well as those more nearly resembling 
artificial implements, if they are not actually such, appear greatly to differ in 
age. Some of the specimens are as sharp and fresh in appearance as if Ijut 
recently shivered from the parent block, while others are so mucli worn and 
so deeply altered from exposure that they look to be of ancient date. In 
some of these old-looking specimens .the jasper, originally brown or black, 
has become dull white and yellow tlie depth of one-fourth of an inch from 
the surface.* 

*Iu tbis relatiou I luay take the opportuuity to refer to one of the simplest of stoue 
iiuplemeuts, still in use, and which, if it had alone been found among the flaked ma- 
terials of the butte.s, would certainly have been viewed as an accidental spawl. During 
uiy stay at Fort Cridger, the Shoshone Indians made a visit to the post and encamped 
in its vicinity for a week. Being the first time that I had had an opportunity of seeing 
a tribe of Indians, I felt much interest in observing them. While wandering through 
their camp I noticed the women dressing buffalo-skins with a stone implement, the 
only one of this material I found in use among them. A serrated scraper of iron was 
also employed, but the stone implement was clearly a common and important one. It 
was a spawl from a quartzite bowlder made by a single smart blow with another stone. 
It is circular or oval, plano-convex, and with a sharp edge. The implement is repre- 
sented in the accompanying figure 13, and according to Dr. Garter, who is quite 
familiar with the language and habits of the Shoshoues, is called by them a " te-sho-a." 
By a happj^ accident I learned that it was not a mere recent instrument incidental to 
the time and place. 

While on an excursion after fossils, in com])any with Dr. Carter, I noticed on the side 
of a butte a few weathered human bones, to which I directed the attention of my friend. 
On further examination, we found others, together with some perforated canines 
of the elk and one of the identical "teshoa" above described. Dr. Carter observed 
that the Shoshones sometimes buried their dead upon the top of prominent buttes, 
and these remains had fallen from the grave of a squaw, which in the cour.se of time 
had become exposed by the wearing away of the edge of the butte. The bones and 
elk-tusks were much weathered. Their appearance and the probable circumstance 
that several years had elapsed before the butte could wear away to reach 'the grave, 
appear to be sufBcient evidence that the "teshoa" was an implement of common use. 

To this note I may add a remark relating to the perforated canines of the elk. They 
are worn as ornamental trophies by the Shoshones and other Indians. In a recent 
number of the American Journal of Science and Art, for 1872, page 211, in a notice 
"On fossil man of the cavern of Brousse-rousse, in Italy, by E. Riviere." I notice that, 
besides a human skeleton associated with the bones of many extinct animals, there 
were also found several flint knives and a number of perforated canines of the stag. 
In addition to the common form of many of the stone implements, this is a significant fact 
bearing on the probability of a common origin to the races of man. One of the siieci- 
mens of perforated tusks of the elk from the Indian grave is represented in Fig. 11, 
at the end of this introductory chapter. 



23 

As the clays ami saiulstoiies of the Bridger terraces and builds cniiiiblo 
away, a variety of renuiins of terrestrial and fresh-water animals are exposed 
(o view. lu some of the buttes they are comparatively aljundant; in otiiers, 
they are rare. The fossils consist of the bones and teeth of vertebrates, and 
the shells of molliisks. Fragments of silicified wood also occur, though 
not frequently. Shells of the san.dstones are composed of chalcedony ; Ijut 
those imbedded in the indurated clays usually retain their carbonate of lime 

The fossil bones are completely petrified ; that is to say, their more per- 
ishable constituents have been replaced mainly by siliceous matter. They 
are frequently as black as ebony ; and the teeth are usually black, with the 
enamel highly lustrous. Often they are brownish, with a greenish aspect, 
derived from the greenish matrix in which they were imbedded. They are 
also found of a yellowish clay color and duller aspect. 

Many of the bones are more or less crushed and distorted, as a result of 
the pressure of the superincumbent strata. The fragments are generally but 
slightly dislocated, showing that the crushing occurred while they were 
imbedded. The stronger bones are often well preserved, especially the rami 
of lower jaws and teeth, and the smaller bones of the wrist and ankle. 
Whole skulls are exceedingly rare, and when discovered are much crushed 
and distorted. ' Turtle-shells are among the most frequent fossils, but are 
usually more or less fractured, crushed, and distorted. In searching over 
the buttes, little piles of bone-fragments are often seen diverging froni a 
prominent point. These, on examination, generally prove to be the remains 
of a turtle-shell which, after exposure, has fallen to pieces. 

Generally the fossils are sharply preserved ; that is to say, they rarely 
have a rolled or water-worn appearance, indicating that bones and shells 
were soon enveloped in mud at the bottom of comjjaratively quiet water. In 
the gravelly strata rolled fragments of bones are found. 

Nearly all the fossils collected from the Bridger I)eds, and descriljed in 
the succeeding pages, have been collected as loose specimens picked up on 
the surface of the buttes. No excavations have been made into the latter in 
search of fossils, except to exhume a partially exposed bone, or some parts 
of a skeleton supposed to be contiguous to specimens lying in view on the 
surface. Usually only a few pieces of a skeleton have been found together, 
and in no instance has a complete one been discovered which has been 
brought to my notice. Generally, too, there has been no certainty that bones 



24 

or iVagments tbiiiul together belonged to tlie same .skeleton, and in must 
instances they have appeared to belong to several ditierent animals. 

The remains of vertel)rates thus far discovered in the Bridger Tertiary 
formation represent all classes except Batrachians, and these no doubt 
formed members of the ancient fliuna : but their delicate bones have, as yet, 
escaped detection. 

The remains of mammals are especially numerous, and they belong to 
many genera, most of which are extinct, and had not been previously 
described or tbund elsewhere. The greater proportion of the mammals were 
odd-toed pachyderms, whose nearest living allies are the tapirs. Proboscidian 
and equine forms appear to have been sparsely represented. Even-toed 
pachyderms were comparatively few ; and ruminants, whose remains are so 
abundant and varicil in the later Tertiary formations east of the Rocky 
Mountains, appear to have been absent. The other remains of mammals 
belong to rodents, insectivores, and carnivores, nearly all of extinct genera, 
not previously described nor found in other localities. Primates, bats, mar- 
supials, and edentates are probably represented, but have not been certainly 
recognized among the fossils which I have had the opportunity of examining. 
The nature of the formation from which the remains are obtained is such 
that we do not expect to find evidences of the remaining orders of mammals. 

No remains of birds have come under my notice; but Professor Marsh, 
who has explored the Bridger Tertiary beds with unusual facilities and great 
diligence, has reported the discovery of specimens which he attributes to half 
a dozen species of two extinct and previously unknown genera.* 

Of reptiles, the remains of turtles are, perhaps, the most abundant fossils 
met with in the buttes of the Bridger basin. They belong to a number of 
different genera, several of which are extinct, but others belong to genera 
still in existence. Most of them are aquatic forms, but one at least was a 
land-tortoise. The number of species and genera is in striking contrast with 
the single species, represented by a multitude of individuals in the Tertiary 
deposits of White River, Dakota, and of Niobrara River, Nebraska. 

The turtle remains mostly consist of the shells, often nearly complete, 
and sometimes including other bones ot^ the skeleton imbedded in the interior 
matrix. 

The remains of crocodiles, which are entirely wanting in the White 

* Am. Jour. Sc, 1872, p. 25G, 



25 

River iind Niobrara Tertiaries just mentioned, are frequeiil in the Ijiidger 
beds, and represent several species. 

Remains of lizards also, allied to the modern iguana and monitor, are 
found as associates of the Bridger fauna. Professor Marsh has likewise 
reported the discovery of remains of serpents, which he ascribes to several 
species and genera. 

Multitudes of well-preserved fresh-water fishes are found in the Green 
River shales. They are chiefly cypi'inodonts and herrings, and, for the most 
part, have been described by Professor Cope. 

Black, shining, enameled scales, teeth, and vertebrae of ganoid fislies are 
frequent among the fossils of the Bridger beds. 

The Tertiary strata of Green River and its tributai'ies, including the 
latter, as indicated l)y the character of the vertebrate fossils, are much older 
than the tertiaries of the Mauvaises Terres of AVhite River, Dakota, and of 
the Niobrara River, Nebraska. They overlie the cretaceous rocks, with wiiich 
they are unconformable, and they are probably contemporaneous with the 
Eocene formations of Europe. 

Attention was first directed to the Green River Tertiary formation, 
which has proved to be so rich in tlie remains of vertebrates, by the late Dr. 
John E. Evans, as early as 1856. From Green River he obtained a speci- 
men of shale, witli a well-preserved fish, represented in Fig. 1, Plate XVII, 
of tlie present work, and briefly described by the writer, under the name of 
Clupea humiUs, in the proceedings of the Academy of Natural Sciences of 
Philadelphia, for October, 1856. 

In 1868 Dr. J. Van A. Carter, of Fort Bridger, in correspondence with 
the author, informed him of the frequent occuri-ence of the remains of turtles 
and other animals in the buttes of the neighboring country. The same year 
Professor Hayden, during his geological explorations, obtained remains of a 
Trionyx from Church Buttes. Colonel John H. Knight, United States Army, 
also procured a vertebra of an extinct crocodile from the same formation of 
Bitter Creek. These remains, together with those of a small insectivorous 
animal, discovered liy Dr. Carter on the Twin Butte, near Fort Bridger, were 
described by the writer in the Proceedings of the Academy for April, 1869. 
The little insectivore was named Omomys Carieri in honor of its discoverer, 
and is also described in " The Extinct Mammalian Fauna of Dakota and 
Nebraska." The specimen upon which it was characterized is represented in 
4 G 



26 

Figs. 13, 14, Plate XXIX, of that work. Subsequently, during 1869 and the" 
ibllowing years down to the present time, the Green River basin has been 
sedulously explored by Professor O. C. Marsh with the most important and 
fruitful results. In the abundance of fossils and the number of extinct genera 
and species of vertebrates they represent, his collections are perhaps not 
exceeded by any obtained from any one locality elsewhere in the world. 
Professor Marsh has given a succinct account of the geology of the region in 
the American Journal of Science for 1871, and in the succeeding volumes 
brief descriptions of the many species and genera of extinct animals discov- 
ered hy him. 

In 1869 Professor Hayden, during his geological exploration of Wyoming, 
also examined the Green River Tertiary formations, and designated the more 
superficial ones under the name of the Bridger group. The fossils collected 
from the latter were submitted to the examination of the writer, and are 
briefly noticed in the Proceedings of the Academy for 1870, and likewise in 
Professor Hayden's reports of 1870 and 1871. 

During the same and the succeeding years down to the present time, Drs. 
Carter and Corson explored the buttes in the vicinity of Fort Bridger and 
discovered many important fossils. Their collections from time to time were 
transmitted to the author, and by far the greater numl)er of the animals char- 
acterized in the following paper are indicated from the specimens of these 
collections. Most of them have also been briefly noticed in the later volumes 
of the Proceedings of the Academy, and in Professor Hayden's reports for 
1870 and 1871. 

I may further remark that during the last summer Professor Cope made 
an extended exploration of the Green River basin, and ol^tained large collec- 
tions of fossils, to a full account of which we look forward with much interest. 




Fig. 14. Perforated elk-tusk; oue of a uiimber of similar specimens fotiuil together with a "te.shoa" 
and human hones which had fallen from an old Indian grave, at the edge of a butte, three miles from 
Fort Bridger. 



27 

MAMMALIA. 

Order Perlssodactyla. 

Hoofed qiiat^rupeds, with functional toes in tlie hind feet, and often like- 
wise in the fore feet, in uneven number. Arrangement of the constituent 
Iol>es of the crowns of the molar teeth unsymmetrical. Feinur with a third 
trochanter. Astragalus with tlie fore part divided into tvv'o very unequal 
articular facets. • 

PAL^OSYOPS. 

Aniong the most aliundant and interesting of the mammalian remains from 
the Bridger Tertiary group, wliich the writer has had the opportunity of 
examining, are those of a genus of odd-toed pachyderms to which the above 
name has been given. The specimens consist of fragments of jaws with teeth, 
isolated teeth, small portions of other parts of the skull, articular ends of 
the limb-bones, and some of the smaller bones of the feet. 

The anatomical characters of the specimens indicate Palaeosyops to have 
been more nearly related with the tapirs than to any other living animals. 
The jaws were provided with nearly closed series of teeth in full number, 
that is to say three Incisors, a canine, four premolars, and three molars to each 
side of both jaws. The canines are as well developed proportionately as in 
ordinary carnivores, and would lead one to suspect that perhaps Palaeosyops 
used a mixed diet of meat and vegetables. 

The genus was originally established in the Proceedings of the Academy 
of Natural Sciences of Philadelphia for October, 1870, on specimens of teeth 
discovei'ed at Church Buttes, Wyoming, during Professor Hayden's geological 
exploration. It was subsequently indicated in Professor Hayden's Prelimi- 
nary Report of the United States Geological Survey of Wyoming, published in 
the spring of 1871, and is there arranged among the artiodactyl or even-toed 
pachyderms. Much additional material, comprising many parts of the skele- 
ton of the same genus, having been received from Drs. Carter and Corson, 
its characters were more fully ascertained, and its true position as a perisso- 
dactyl or odd-toed pachyderm determined. The later account of these is given 
in Professor Hayden's Preliminary Report of the United States Geological 
Survey of Montana, &c., published in the spring of 1872. 

Since then Professor O. C. Marsh has published a notice in the American 
Journal of Science of August, 1872, of some remains ascribed to two genera 



28 

with tlic iKuiies of PaliPosyops luul Liiiuiohyiis. From tlic iiotico it would 
appear he has overlooked the description of Palaeosyops in the report last 
mentioned. He intimates the reference of the genus to the Perissodactyls as 
if previously nnknown, and suggests the reference of specime'ris to it in which 
"the last upper molar has two inner cones," though it is distinctly stated in 
the al)ove report that " the last upper molar of Palaeosyops has but a single 
lobe to the inner part of the crown." Upon this character he founds the pro- 
posed genus Limnohyus, which,' under the circumstances, appears untenable ; 
but if a pair of lobes to the inner part of the crown of the last molar be con- 
sidered a distinctive generic character, the name might be transferred to the 
geiuis possessing it. 

The skull of Palseosyops, and the same may be said of other parts of 
the skeleton so far as they are known to us, approximates in form and 
constitution those of its probably- contemporaneous ally, the Palseotherium 
of the Eocene period of Euroi>e. In both genera the skull presents a 
broad, triangular forehead. In Palaeosyops it is more prolonged posteriorly, 
and is more abruptly curved forward to the root of the muzzle. In both the 
temporal fossae are very capacious, indicating masticatory muscles approaching 
in power those of the great carnivores. In Pateosyops they are separated by 
a much shorter crest than in Pateotherium. In the former the muzzle is rather 
abruptly prolonged forward from the l)ase of the forehead ; in the latter the con- 
vexity of the forehead is continued in the muzzle to tlie end of the nose. In 
both genera the muzzle is broad, but in Palaeosyops the nasals are longer and 
project forward as much as the jaws. The lateral nasal notch is nearly alike in 
both, but is longer in Palaeosyops. In both, the orl)its are open behind, and are 
defined from the temporal fossffi by long, angular post-orbital processes. The 
jaws nearly repeat one another in the two genera. The number of teeth, 
their kind, relation, and general construction, are likewise the same. In 
Palaeosyops they form more unbroken series in the two jaws, as tlu; hiatus 
back of the canines, which is comparatively .large in Paleeotherium, is very 
trilling in extent in Palaeosyops. 

Pal/eosyops paludosus. 

The species Valceosxjops paludosus was first indicated under this name in the 
Proceedings of (he Academy of Natural Sciences of Philadelphia in 1870, and 
was founded on a number of isolated teeth and fragments of others oI)tained by 
Professor Ilayden at Church Buites, Wyoming. Of the specimens, a last 



29 

ujipcr pt'cmdlar is represented in Fig. 5, Plate V; a t'nignieiit of a second 
upper molar in Fig. 6, Plate XXIII, and two lower premolars and a molar 
ill Figs. 3 to 5, of tlic same plate. The teeth apparently all belonged to the 
same individual, which had reached maturity, but had not advanced so llxr as 
to have the summits of the tooth-lobes worn through so as to expose the 
dentine. The enamel is longitudinally wrinkled on the sides of the true 
molars and in a less degree on the premolars. 

The last upper premolar (Fig. 5, Plate V) has a trilolate crown consisting 
of an outer pair of acute pyramidal lobes, and an inner larger conical lobe 
embraced by a basal ridge in front and l^ehind. 

The fragment of an ui)per molar (Fig. 6, Plate XXIII) consists of the tore 
jiart of the crown, and is composed of an outer crcscentoid pyramidal lobe 
and an inner smaller conical lobe. A strong convex buttress forms tiie aiitero- 
external angle of the crown, and a moderate basal ridge bounds it in front. 
A conspicuous tubercle, the rudiment of an additional lobe, occu|>ies the angu- 
lar interval between the principal lobes and the basal ridge. 

The lower molar tooth (Fig. 5) has a fore and ait bilobed crown as in 
PaliEotheriuin and Titanotherium. The lobes arc crcscentoid pyramidal, and 
the anterior is the smaller. 

The lower premolars have the same essential constitution as the true molar, 
but are less well developed. In the fourth premolar (Fig. 4) the relative size 
of the lobes is reversed, the anterior being the larger, and the postero-internal 
liuttress of the crown is obsolete. In the third premolar (Fig. 3) the j^jste- 
rior lobe is still more reduced in size, the anterior lobe is proportionately 
enlarged, and the inner buttresses of the crown are obsolete. 

The measurements of the specimens are as follows : 

Lines. 

Fore and aft diameter of second uppci' luolar, estimated 17 

Transverse diameter of second upper molar IS 

Fore and aft diameter of last upper premolar !»A 

Transverse diameter of last upper premolar ■ 1'2 

Fore and aft diameter of second lower molar 10 

Transverse diameter of second lower molar 10 

Fore and aft diameter of fourth lowei' premolar ". 9i 

Trauisverse diameter of fourtli lower premolar (>i 

Fore and aft diameter of third lower premolar ..... S| 

Transverse diameter of third lower premolar. ; ~> 

Shortly after the original description of the above specimens, several others 



30 

were received from Professor Hayden, obtained on Henry's Fork of Green 
River, Wyoming, wliioli are referred to in the last paragraph of the same 
article of the Proceedings above mentioned as the former ones. The addi- 
tional specimens consist of several small jaw-fragments, with teeth, belonging 
to an individual past maturity, as indicated by the worn condition of the 
latter. 

One of the specimens, a much-worn last upper premolar, is represented 
in Fig. 4, Plate V. It agrees with the corresjjonding tooth above descrilied 
l)()th in form and proportions. The summits of the three lobes of the crown 
arc worn down so as to expose large tracts of dentine. 

A second specimen consists of an upper-jaw fragment retaining a portion 
of tlie first molar and the complete second one. The former was so much 
worn as to have a great part of the enameled triturating surface removed. 
The sccon'd mohu.-, represented in Figs. 8, 9, Plate V, has a low trapezoidal 
crown composed of four lobes, of which the anterior two agree in constitu- 
tion and proportions with the fragment of the corresponding tooth above 
described. The outer pair of lobes are crescentoid pyramidal and bounded 
externally by strong convex buttresses. The inner lobes, of which the an- 
terior is much the larger, form broad cones. A strong basal ridge bounds 
tlie crown in front. The enamel is worn smooth and is abraded from the 
summits of the outer lobes so as to expose broad dentinal tracts. The fore 
and att diameter of the crown of the second upper molar is 16^ lines; its 
transverse diameter is 18 lines. The remaining specimen consists of an 
upper-jaw fragment containing the last molar, represented in Figs. 6, 7, 
Plate V The tooth is fractured and its parts somewhat dislocated, so as to 
extend its breadth. It has the same constitution as the former tooth, except 
that it has ])ut a single internal lobe, which in great part is broken away in 
flic specimen. 

Many more complete specimens referable to Palceosyops paludosus have 
been received from Drs. Carter and Carson. One of the most important of 
these consists of the facial portion of a skull containing nearly all the molars 
and the canines of both sides. The specimen submitted to my examination 
bj D.r. Carter, represented in Fig. 51, Plate XVIII, was discovered in a 
greenish frialde sandstone of the Grizzly Buttes. The tixce is entirely broken 
away at its upper part and fore extremity. The molar teeth, of which a full 
scries is represented in Figs. 3, 4, Plate IV, are fijr the most part preserved 



31 

entire, but the canines, of which one is represented in Figs. 2, 3, arc broken 
off at the crown. Tlie specimen pertained to an individual past maturity, as 
indicated by the worn condition of the teeth. Tiie enamel is ai)radcd from 
the summits of the outer lobes of the last premolar and the molars and the 
summits of the inner lobes of the first molar, so as to expose tracts of den- 
tine. Elsewhere the enamel is worn smooth, but remains of its original 
rugose condition are yet visible in the last molar. In anatomical character 
and proportions the teeth agree in all respects with those corresponding 
among the specimens above described. 

The molar series consists of seven teeth which successively increase in 
size from first to last. The molars or true molars approach in character those 
of Titanotherium, and in a less degree those of Anoplotherium and Chalico- 
therium. The crown is broad and low and rather rhombic in outline. It is 
composed of four principal lobes expanding in a common base. The outer 
lobes are the larger and have the shape so common in many allied animals as 
Palisotherium, Ancliitherium, Anoplotherium, Oreodon, Cervus, &c. They 
are three-sided pyramids with crescentoid summits, the anterior extensions of 
wliich form stout external buttresses to the crown. The inner lobes are 
broad cones less prominent than the outer lobes. Tlic anterior is the larger, 
and is situated opposite the angular recess of the outer lobes; the posterior 
occupies a position opposite the postero-internal face of the contiguous outer 
lobe at the inner back corner of the crown. 

A strong basal ridge occupies the fore part of the crown, and elements of 
the same are found at the bottom of the outer faces of the external lobes. A 
tubercle exists in the angular interval of the anterior lol)es and the basal 
ridge in front, which looks as if it were the rudiment of the large antero-in- 
ternal lobe in Anoplotherium and its homologue in ordinary ruminants. 

In the last molar the postero-internal Ipbe, as existing in the molars in ad- 
vance, is absent or is substituted by a small tubercle extending outwardly as a 
posterior basal ridge to the crown. 

In the unworn condition of the upper molars of PalfEosyops the external 
lobes of the crown have acute crescentoid summits which conjoin on the sum- 
mit of the median outer buttress. As the teeth were worn away in mastica- 
tion, a W-shaped tract of dentine appeared on the outer lobes, and this gradu- 
ally widened with the progress of abrasion. As the summits of the inner 
lobes were worn away, circular islets of dentine made their appearance, 



32 

which likewise gradually expanded as a result of mastication. A continuance 
of the process would unite the inner and outer tracts, and in an advanced 
condition of abrasion the distinction of the four lobes with the intervening 
valleys would be obliterated, leaving a broad concave dentinal surface bordered 
by the enamel at the sides of the crown. 

The upper molars of Pateosyops, while presenting considerable resemblance 
to those of Pateotherium, also exhibit well-marked differences. They differ 
especially in the greater prominence and more robust character of the ex- 
ternal Ijuttresses of the outer lol^es, in the form and more complete isolation 
of the inner lobes, and in the absence of the deep pit at the termination of 
the oblique valley of the crown. 

In comparison with the upper molars of Anoplotherium, those of Palfeo- 
syops especially differ in having proportionately stouter buttresses to the 
crown externally; in possessing but a rudiment of the antero-internal lobe as 
existing in the former, and in the different shape and relationship of position 
of the postero-internal lobe, whicli in Anoplotherium has the form nearly of 
the contiguous outer lobe and embraces it as in the deer. 

In comparison with the corresponding teeth of Chalicotherium, several ini- 
poi'tant differences are observable. Of the outer buttresses of the crown in 
this genus, the posterior is the larger, but in Pateosyops the anterior is the 
larger. The antero-internal lobe is proportionately less prominent, and the 
postero-internal lube has a different shape, being nearly like that in front of 
it, and it is completely isolated. In Chalicotherium it is more like that in 
Anoplotherium, and it joins the fore part of the postero-external lobe. In 
flic last molar of Palseosyops the postero-internal lobe is obsolete, but in 
Chalicotherium is proportionately as well developed as in the other molars. 

As previously intimated, it is to the upper molars of Titanotherium that 
lliose of Pateosyops have most resejnblance. The abrupt and deep pit near 
the centre of the crown is absent. The rudimental lobe at the fore part of 
the crown between the anterior principal lobes is proportionately less de- 
veloped, and yet is more isolated from the basal ridge. In the last molar the 
postero-internal lobe is nearly suppressed, while in Titanotherium it is still a 
conspicuous clement of the crown, though less well developed than in (he 
other molars. 

The premolars of PaliEos3'op.s undergo a successive reduction forward and 
assume a more and more elemental condition. 



Tlio (burili prciiiular lias uii (iljloiiir stjuiiro crown uilh (lie, IraaHverse 
diameter exceeding that fore and aft, and witli the inner part nearly semi- 
circular. The crown is composed of three lobes, corresponding with the 
outer pair of the molars, and apparently the large inner one situated opposite 
the recess of the former. The outer lobes are like those of the molars, with 
the back one proportionately less well developed, with the outer median but- 
tress of the crown suppressed, and with the outer median fold of the antero- 
external loI)e more prominent. The inner lobe is a single, broad, undivided 
cone less prominent but rather larger than the outer ones. It appears to be 
homologous alone with the anterior of the inner cones of the molars, and at 
least does not appear to be a connate pair as in the corresponding tooth of 
Titanotlierium. The conspicuous pit in the center of the crown in this 
genus is absent in Palseosyops. A thin basal ridge starting in front and back 
of the internal lobe festoons the crown outwardly and at the bottom externally 
of the outer lobes. 

The third premolar is a diminished representative of the one behind, but 
has its antero-external lobe proportionately a little larger, and the [)ostcro- 
external lobe proportionately reduced. The teeth of the two sides are not 
symmetrical in the specimen. That opposite to the one represented in the 
figure has its fore part broken away, but the postero-external lobe is consider- 
ably longer than in the entire tooth. 

The second premolar has a trihedral crown, in which but two lobes are 
conspicuous. In comparison with the premolars behind, the internal loi^e is 
greatly reduced in size, and the antero-external lobe is much enlarged so as to 
become the main portion of the crown, while the postero-external lobe is ob- 
solete. 

The first premolar is a small tooth separated from the others by a slight 
interval. It has a simple short conical crown with the base slightly extended 
backward, and is inserted by a pair of fangs. The other premolars and the 
molars are inserted with three fangs, of which the inner one in the latter 
teeth consists of a connate pair. 

The canine teeth of Palasosyops were powertul and efticient weapons, and 
resembled those of ordinary carnivores more than they do those of nearly 
allied living animals. Though imperfect in the specimen under consideration, 
the remaining portions, as represented in Figs. 2, 3, Plate IV, indicate teeth 
of the form and proportions of those of living bears. They also ajipear to 
have nearly the same relative i)osition with the other teeth and the same 



•34 

direction ;i.s in Uil^ latlcr. Tlie fang is robust and gibbous, and comes from 
the alveolus in a direction downward and forward with a greater degree of 
divergence than usual among carnivora. The face of Palseosyops, judging 
from the imperfect specimen, a side-view of which is given in Fig. 51, Plate 
XVIII, in its complete condition, would appear to resemble in shape that of 
tiie Elotherinm of White River, Dakota, cxcejit that the muzzle was pro- 
■ portionately shorter. Among living animals, it appears to have resembled 
that of the bears niort; than in those nearly related to it. The zygomatic 
arches are of rol)ust proportions and widely divergent at their anterior attach- 
ment to the face. The malar portion of the zygoma is divided by an acute 
ridge curving from the anterior orbital margin outward, downward, and back- 
ward. The surface above this ridge curves outwardly and downward from 
the floor of the orbit continuously. The surface beneath is a broad trilateral 
plane looking forward, downward, and outward, and is roughened for the at- 
tachment of a powerful masseter muscle. The space behind the anterior 
abutment of the zygoma indicates a temporal fossa of large capacity. 

The orbit appears low, and is directed obliquely forward and outward. 
In advance of the prominent antorbital margin the side of the face is nearly 
vertical. The infra-orbital foramen is rather large, and is situated over the 
position of the last premolar. In front of the foramen begins the swell of the 
large canine alveolus, and below its position is the alveolar border, marked by 
the vertical ridges of the molar fangs. The hard palate is well arched, and 
nearly parallel at the sides. Its surface in the specimen is obscured by the 
attachment of rocky matrix. The breadth of the face at the zygomata 
appears to have al^out equaled the length. 

The measurements of the specimen are as follows: 

Inches. Liu6s. 

Breadth of face at zygomata ou liue with middle of hxat molar.s 7 8 

Breadtli of face outside of last molars i C 

Breadth of face outside of canine alveoli 3 G 

Breadth of face at infraorbital foramina 3 2 

Breadth of bard palate between last molars 1 7 

Breadth of hard palate between last premolars 1 o 

Distance from back of last molar to fore part of canine S 

For comparison, the measurements of the teeth will be given after the 
description of the following series. 

Some additional specimens, which I suppose to belong to Palaosyops 
paludosus., notwithstanding certain dilferences hereafter to be mentioned, con- 



35 

sist of most ot" the upper teeth, with small attached jaw-fragments, obtained 
l)y Dr. Carter on Henry's Fork of Green River. Of these specimens a com- 
])lctc series of nearly perfect molar teeth is represented in Figs. 5, G, Plate 
IV. The teeth in their abraded condition ilidicate an older animal than that 
to which the facial specimen above described belonged. The summits of the 
constituent lobes of the teeth are nearly all worn to such a degree as to 
exhibit tracts of dentine, and the enamel is everywhere smooth, except on 
the external faces of the outer lobes near the basal ridge. 

The molars are almost identical in character with those above described 
ill the facial specimen. Trifling differences consist in the less production of 
the median fold on the outer face of the external lobes, and perhaps the less 
degree of prominence of the tubercle in the interval anteriorly of the anterior 
pair of lobes. The last premolar is likewise identical with those above 
described, except that its crown is rather more square, or is not quite so 
wide. The anterior three premolars depart considerably from their character 
in the facial specimen, and their differences may probably indicate a different 
species. The third premolar is a diminished representative of the one behind 
it, the three lobes of the crown holding nearly the same proportionate devel- 
opment; whereas in the corresponding tooth of the facial specimen the pos- 
tero-external lobe is considerably reduced in its proportions. In the second 
])remolar the crown still retains a postero-external lobe reduced in proportion 
to the others, but in the corresponding tooth alaove described it is obsolete. 
The retention of this lobe gives the crown a greater fore and aft breadth than 
that contained in the facial specimen. The first premolar has the same form 
as that of the latter, but it is much lai'ger. 

The mutilated canine, accompanying the molars first described, is repre- 
sented iu Fig. 1, Plate IV, and is but little more than half the size of those 
contained in the facial specimen. 

An isolated incisor, represented in Fig. 8, accompanying the molars and 
canine just described, is regarded as an upper one. Tiie crown is mutilated, 
l)ut when complete appears to have had a short, conical crown, bounded 
behind by a strong basal ridge. The fang is laterally compressed, and is 
about an inch in length. 

Comparative measurements of the series of teeth of the two individuals of 
Palseosyops. indicated by the facial specimen, with teeth, from Grizzly Buttes, 



36 



and the specimens of (eetli IVoiu Henry's Fork, just described, are as 
follows : 



Si)ace occupied by the entire molar series 
Space occupied by the true molar series . 
Space occupied by the premolar series . . 



Liucs. 



G9 
41 

28 



Lines. 



71 
■11 
32 



Diameter of lirst premolar . 
Diameter of secoud premolar 
Diameter of third premolar 
Diameter of fourth premolar 

Diameter of first molar 

Diameter of secoud molar . . 
Diameter of last molar 



Autero- 
jiosterior. 



Lines. 

5 

G 

7 
10 
12 
1(3 
17 



Transverse. 



Lines. 

3 

7 

8 
lOi 
13 
17 

m 



Antero- 
posterior. 



Lines. 

7 

8 

8 

8 
12 
15 
17 



Transverse. 



Lines. 

4 

7 

9 
10 
12i 
W 
IGJ 



Lines. 



Lines. 



Length of faug of upper canines 

Autero-posterior diameter of canines 
Transverse diameter of canines 



28 
12§ 

m 



18 

7 



The question arises whether the differences which have been indicated in 
the [)remolars and canines of the two different series of teeth above described 
indicate more than one species. The differences are clearly in degree of 
development and size, and these may probably be of a sexual character. The 
individual with the more powerful canines I suppose to have been a male, in 
which, with a greater proportionate degree of development of these oi'gans 
than in the female, there appears to have been a reduction in the degree of 
development of the anterior premolars. 

Another sjieciinen submitted to my examination by Dr. Carter, and repre- 
sented in Figs. 6, 7, Plate XXIV, belonged to an older animal than the 
former, as indicated by the more worn condition of the teeth. The latter 
consist of the anterior three premolars and a portion of the fang of the canine, 
and they have the same form and proportions as the corresponding teeth 
above described. The first premolar is close to the others, or is iiot sepa- 



37 

rated l)y a coiispiouoiis interval as in (he Ibrmer s[)ccini(ni. Tlie lolx's ol' llic 
second anil third premolars are worn nearly to a level with tlieir l)ase. Tin; 
outer surtiice of the maxillary, as seen in Fig. G, is defined by an oijliijiir 
ridge at the nasal border, within which the suture of the premaxillaiy ])ur- 
sues its course over the position of the fang of the canine. Just outside of 
the nasal border the surface of the maxillary is depressed. 
The measurements of the specimen are as follows : 

Lines. 

Space occupied by tlie anterior tln-ee premolars 21 

Autero-posterior diameter of first premolar G^ 

Transverse diameter of first premolar 3;^ 

Autero-posterior diameter of second premolar 7 

Transverse diameter of second premolar G^ 

Autero-posterior diameter of third premolar 8 

Transverse diameter of third premolar 9 

Diameter of fang of canine 8 

Fragments of half a dozen lower jaws referable to Palseosyops, collected in 
various localities in the vicinity of Fort Bridger by Drs. Carter and Corson, 
have been submitted to my examination. 

A well-preserved specimen, consisting of the greater part of the jaw, was 
discovered by Dr. Carter imbedded in a greenish gravel thirteen miles soutii- 
east of Fort Bridger. The right ramus is represented in Fig. 11, Plate V, and 
it contains the molars and the back two premolars, which are also repre- 
senteil with a view of the triturating surfaces in Fig. 10 of the same plate. 
The teeth, corresponding with those in part upon which the species Palceo- 
syops paludosus was originally indicated, are identical in anatomical chaiacter 
and so nearly in size that the jaw may be regarded as pertaining to the sam(> 
species. 

In advance of the teeth retained in the jaw there are indications of two 
additional jM-emolars verging close upon the remains of the canine alveolus, 
and thus the specimen shows that the number of the lower molar series of 
Palseosyops is seven. 

The lower molars of Palaeosyops resemble those of Palseotherium and 
Anchitherium, but even more closely those of Titanotherium. The crowns 
arc ])roportionately wider and lower, or appear more robust than in the formei- 
genera. 

The crown of the anterior two molars is quadrately oblong oval, with the 
fore and aft diameter largest and the depth less than the width. It is com- 
posed of two divisions or lobes, one in advance of the other. The last molar 



38 

has llie same form and coiistriictioa, with the addition of a third but smaller 
lobe. 

In tlie ninvorn molars the principal constituent lobes present acnte cres- 
centoid summits embracing a concavity which opens to its bottom by an 
angular notch on the inner side of the crown. The contiguous arms of the 
crescentoid summits conjoin in a strong conical eminence situated just in 
advance of the middle of the crown internally. The point of this eminence 
is simple or undivided ; in Anchitherium it is deeply indented and appears to 
he composed of a connate pair of eminences. 

The fore part of the summit of the anterior lobe in Palgeosj'ops curves 
downward and inward, and ends in a slight prominence at the anterior inner 
corner of the crown. The hind part of the summit of the posterior lobe ends 
in a prominence like that in advance, but smaller, and situated at the postero- 
internal corner of the crown. 

Externally the lobes of the crown are angularly convex, and include deep 
angular recesses sloping outwardly and downward, and bounded by festooned 
elements of a basal ridge. The inner surface of the crown is nearly vertical, 
smooth, and without a basal ridge. The latter is especially well developed 
at tlie fore and back part of the crown, except in the last molar, in which the 
additional lobe takes its place. This lobe is a much reduced likeness of those 
in advance, with the arms of its crescentoid summit contracted and conjoined 
with the posterior conical eminence of the crown internally. 

The molars undergo a rapid reduction forward, and they are inserted by 
two fangs. The crown of the last premolar is a reduced representative of 
that of the succeeding molar, with the posterior lobe proportionately, in 
comparison with the anterior lobe, less well developed. In the crown of the 
third premolar there has been a further proportionate reduction in the back 
lobe, but the anterior remains nearly the same, except that it appears more 
robust from its connation with the homologue of the anterior of the inner 
conical eminences of the teeth behind. 

In Pateotherium and Anchitherium the corresponding premolars with those 
described repeat the form of those of the molars, and in this respect greatly 
differ from Palseosyops. The inferior premolars of Titanotherium in a perfect 
condition are not sufficiently well known to instittvte a comparison with those 
of Palseosyops. 

The lower molars of Palseosyops in wearing would assume the same 



39 



apjiearance as those of Palaeotheriuin and Anchitheriiiin at the same stages <>( 
attrition. 

Tlie space occupied 1)}' the entire molar series is estimated at al»oiit G.^ 
inches, of whicli the true molars occupy ratlier less tlian 4 inches. 

The measurements of the molar teeth contained in the lower jaw are as 
follows : 



Antero- 
posterior. 



Transverse. 



Diameter of tbird premolar . 
Diameter of fourth premolar 

Diameter of first molar 

Diameter of second molar. . . 
Diameter of last molar 



Lines. 
8i 
9 

15 
19 



Lines. 

8 
10 



The premolars are inserted by a pair of fangs, except the first, whicli has 
but a single fang. 

The lower jaw of Palceosyops, as seen in Fig. 11, Plate V, appro.ximates in 
form that of the tapir and hog, though presenting important differences. 
The dentary portion of the ramus is proportionately shorter and deeper than 
in either of those animals, and the alveolar border is more ascending poste- 
riorly. The base is more convex fore and aft than in the hog but less than 
in tiie tapii', and is more obtuse than in either. The outer surface is vertical, 
with a slight outward slope at the fore part. 

The back part of the jaw is of more uniform breadth than in the tapir, and 
is more like that in the hog. Toward the angle the outer surface is a verti- 
cal plane, with the lower border or base more directed downwardly timn in 
the hog. The upper or ascending portion presents a masseteric fossa about 
as deep as in the tapir but of considerably greater width. 

The condyle is large and thick, and much like that in the tapir, but is less 
inclined inwardly. It has about the same proportionate elevation above the 
level of the base of the jaw, but less above the level of the teeth. 

The border of the jaw below the condyle behind is at first slightly concave 
and then convex, as in the hog, but to a less degree. The coronoid process 
is about as long as that of the tapir, but the fore part curves upward and 
l)ack\vard without any inclination forward. The notch behind hardly descends 
below the level of the condyle. 



40 

The mental turiiincii is siiiallcr tliaii in (ho tapir, and is .situated l)el()\v the 
interval of the second and third picniolars 

The length of the lower jaw, fi-om its back border to the fore part of the 
second premolar, is [)'\ inches, and in the complete condition it measured 
about 2 inches more. 

Portions of several lower jaws, apparently all referable to Palseosyops, were 
ol)tained by Dr. Corson at Grizzly Buttes. The specimens exhibit some 
variation in character, and may, perhaps, belong to more than one species of 
the genus. One of the specimens consists of a dentary fragment containing 
(he true molars and the fangs of the two premolars in advance. The retained 
teeth are like those previously described, but are in a trifling degree smaller. 
The series measures 3| inches. The jaw-fragment nearly agrees with the 
corresponding portion of the specimen above described, but is of more uniform 
depth. 

Another specimen consists of a right ramus, without the chin and back 
part, and broken into three pieces. It contains the fang of the canine and 
most of those of the molars. The jaw is of more uniform depth below the 
position of the teeth than in the more complete specimen first described, and 
more robust than in cither of the former specimens. The retained portion 
of the fang of the canine indicates a larger tooth than existed in the first- 
described specimen — one, also, that would accord in its robust character with 
those of the facial specimen referred to Palceosijops iJcdudosus. The presence 
of the fang of the canine produces a strong bulge at the side of the chin, 
which apj/cars to have been comparatively feeble in the first-described speci- 
men. Two mental foramina are situated below the position of the second 
and third premolars. The first premolar appears to have had a single fang 
consisting of a connate pair. It was separated from the canine and second 
premolar by conspicuous intervals, the posterior of which is the larger. A 
])ortion of the chin being retained in the specimen, it would a})pear in the 
entire condition to form a broad slope defined at the sides liy the convexities 
of the canine alveoli. The rami were completely co-ossified at the symphysis 
witiiout the suture of union being apparent. 

The remaining specimen consists of a portion of the jaw containing the 
limgs of the last two molars, and the portion immediately jjehind extending 
toward the angle. The dentary portion of the bone is considerably deeper 
(hau ill (he corresponding portion of Ihe preceding specimens. The l)ase 



41 



below Uie posilum (if llic last nioliir lootli is rafhcr more eonspiciKiusly lulicr- 
ous and roughened for muscular attachment, and the concavity back of this 
is more posterior and deeper than in the first-described specimen. 

Comparative measurements of the lower-jaw specimens, including the one 
first described, are as follows : 



Space occupied by tlie entire molar series 

Space occupied by the molars and last two premolars . 

Space occupied by the true molars 

Distance from last molar to back of jaw 

Width of ramus back of condyle 

Depth of ramus at middle of last molar : . . 

Depth of ramus below last premolar 

Thickness of base below second molar 

Anteroposterior diameter of last molar 



No. 1. 



Lines. 



C4 
.40 
49 
44 
31 
23 
13 
19 



No. 2. 



Lines. 



05 
48 
48 
41 
3U 
23 
11 
20 



No. 3. 



Lines. 



00 
4.5 



33 
20 

12 
19 



No. 4. 



Lines. 
78 

02 
45 



33 
29 
13 
19 



A small fragment of the chin of a lower jaw, referable to Paleeo.syops, 
retains part of the alveolus of a large canine, and portions of the fangs of 
three incisors of the same side, thus indicating the number of the latter teeth 
in the animal. The canine alveolus has been about an inch in diameter. In 
the ramus of the jaw above described, retaining the fang of a canine, this 
tooth has been nearly in proportionate size to that of the alveolus just men- 
tioned. 

Small fragments from three different skulls, attributable to Palceosyops, 
consisting of portions of two sagittal crests and the supra-occipital, indicate 
capacious temporal fossa?, separated by a short, thick crest and a broad 
occiput. 

The fragments of sagittal crests arc from the fore part, retaining the suture 
and notch for the summit of the frontal. The upper surface of the crest is a 
flat triangle, slightly depressed at the middle, with the notch for the frontal 
in its base. In the latter position it is li inches wide; and a couple of inches 
back of this position the crest is !| of an inch thick. 

The occipii'il fragment on each side in front presents a widc!, sloping sur- 
face, which contributes to the temporal fos.sa. The posterior surface in 
general ap])earance resemljles that in the rhinoceros. Tiie upjier ])ortion 
forms a broad, even concavity, undivided by any trace of a vertical ridge, and 
6 G 



42 

only loiigliened at tlic siiinmit for the attachment of the nuchal ligament. 
The lateral processes are angular and ilivei-gent, and the space between them 
is 4^ inches in width. The lower portion of the occipital surface approaching 
the occipital foramen is convex. The height of the occiput fi-om the latter is 
about 4f inches. 

A lumbar vertebra was found by Dr. Corson at Grrizzly Buttes. It pre- 
sents the ordinary ungulate form. The body is 2 inches long, but some- 
what shortened below. It is concave fore and aft, at the sides, and beneath, 
where it is also slightly carinate. The anterior extremity is slightly convex, 
li inches transversely, and a little less in depth to the prominence beneath. 
The posterior surface is .flat, or feebly depressed. The transverse process 
springs from the upper level of the l)ody. A well-developed metapophysis 
])rojects from the position of the anterior zygapophysis. The diameter of the 
spinal canal is about an inch. 

Besides the skull-fragments and vertebra of Palasosyops, a number of 
isolated carpal and tarsal bones, and many fragments of the long bones and 
other portions of the skeleton have been collected by Dr. Carter, Dr. Corson, 
and Professor Hayden's party. Many of the bones had been fractured, or 
more or less crushed, while they lay in their bed, and many have been further 
injured after exposure through the influence of the weather and other causes. 
The bones nearly resemble in size and construction the corresponding ones 
of the American tapir. 

The distal extremity of a humerus, represented in Fig. 3, Plate XIX, was 
found by Dr. Corson in the vicinity of Fort Bridger. The breadth of the 
specimen between the supra-condyloid eminences is 3^ inches. A deep 
sujDra-condj'loid fossa occupies the front of the humerus, opposed to the 
deeper and more capacious olecranon fossa. The articular trochlea is 2.] 
inches wide in front, and narrows an inch less behind. 

A mutilated femur, without the head and trochanters, represented in Fig. 1, 
Plate XIX, was obtained on Henry's Fork, of Green River, by Dr. Carter. 
In its complete condition it has approximated lo inches in length. The 
shaft is three-sided, and at the middle is IG lines in diameter from before 
backward, and 19 lines transversely. The median trochanter projects from 
the outer border of the prismoid shaft, and is higher up in position than in 
the tapir. The distal extremity resembles the corresponding part in the 
latter, but the trochlea for the patella is of less breadth. 



43 

Fig. 2, Plate XIX, i-epreseuts a inucli better preserved distal extremity ol' 
the femur than tiiat of the former. It was obtained by Professor Hayden's 
party at Grrizzly Buttes. At the supra-condyloid eminences it is o^ inches 
in diameter. The width at the condyles is 2f inches. The trochlea for the 
patella, where widest, measures 16 lines. 

The detached head of a femur, in perfect condition, found by Dr. Carter 
near Fort Bridger, measures about 2 inches in diameter. A deep cup-like 
pit for the round ligament approaches the center of the head much more 
closely than in the tapii\ 

A nearly entire femur of Palseosyops, received from Dr. Carter since the 
above was written, is represented in Fig. 5, Plate XXIX. It nearly repeats 
the form of that of the tapir, but rather i-esembles that of the Indian tapir, 
or Baird's tapii% of Gruatemala, than that of the American tapir. In compari- 
son with that of the Taplrus Bairdi, it is rather larger, and the upper 
extremity is proportionately somewhat wider. The inner trochanter is 
longer or more prominent, but the third trochanter is neither so long nor so 
hook-like. 

The measurements of the specimen are as follows : 

Inches. 

Length externally from sumuiit of great trocliauter 15.J 

Width between head and great trochanter 4i 

Width at third trochanter 2| 

Uiaiueter of head 2i 

u 

Diameter fore and aft of shaft at middle Ih 

Width at condyles 3^ 

Fig. 1, Plate XX, represents a nearly entire tibia, obtained by Professor 
Hayden's party at Grrizzly Buttes. The upper condyles are in some degree 
pressed toward each other, and the extremity of the internal malleolus is 
broken off. The bone is not quite so long as that of a tapir with which it 
was compared, but is somewhat stouter. The tuberosity for the ligament of 
the patella is of more robust proportions, and extends lower on the shaft than 
in the tapii-. The ridge descending from it is thicker than in tlie latter — 
straighter, and is obtusely rounded. The length of the tibia is 9 inches ; the 
breadth of its distal end over 2 inches. 

Fig. 2, Plate XX, represents a calcaneum, obtained l)y Dr. Corson near 
the stage-route at the crossing of Smith's Fork of Green River. It is nearly 
like that of the tapir, but is stouter in proportion to its length. The tuber- 
osity of the calcaneum is less comjiressed and is more obtuse in liont. The 



44 

sustentaculum is of nuicli greater extent vertically, and sustains a long ellipti- 
cal facet for the astragalus. The anterior articular facet for the latter is of 
much less extent than in the tapir, and is more distinctly separated from it 
by the interosseous sinus. The articidation for the cuboid is of greater depth 
but less width than in the tapir. 

The extreme length of the calcaneum is 4^ inches. The length of the 
tuberosity is nearly 3 inches. The breadth of the anterior extremity of the 
bone is 2 J inches. 

Of two additional calcanea obtained by Dr. Carter, one was found on 
Henry's Fork of Grreen River ; the other near Millersville. 

Fig. 3, Plate XX, represents an astragalus found by Dr. Carter at the 
bluffs, three miles from Millersville. The trochlea for the tibia is of less ex- 
tent fore and aft than in the tapir ; and the anterior extremity of the bone is 
of less width but greater depth. The length of the astragalus is 2 inches ; 
the breadth of the trochlea twenty lines ; the breadth of the anterior ex- 
tremity is the same, and its thickness is an inch. 

Another astragalus, slightly larger, was obtained by Professor Ilayden's 
party at Church Buttes. 

Fig. 4, Plate XX, represents three tarsal bones obtained by Professor Hay- 
den's party at Church Buttes. They pertained to the same individual, and 
consist of the cuboid, scaphoid, and the outer cuneiform. 

The cuboid is more cubical and stouter than in the tapir. The upper 
surface is more regularly square and nearly a third wider than in that animal. 
The articular facet for the calcaneum has about the same depth, but is nearly 
twice the width. The facet for the first metatarsal bone is also of equal 
depth, but a tliird greater in width. 

The scaphoid is of rather less breadth than in the tapir, nearly of equal 
depth, but not quite so thick. The articular facet for the astragalus is of 
about the same extent, less breadth, Init proportionately more uniform depth, 
and it is less concave. The articular facet for the outer cuneiform is of about 
the same depth, but of much less breadth than in the tapir. The fiicets for 
tiie inner two cuneiforms have about the same extent as in the latter. 

The external cuneiform is about the same depth as in the tapir, l)ut of con- 
siderable less breadth and of greater thickness. 

The metatarsal articular facets of the cuboid and external cuneiiljrm ap- 
pear to indicate that the outer toe of Palasosyops was as large as the middle 



45 

loc, and thai this was much smaller than in the tapir. This a[)|)cars to he 
confirmed by the specimen represented in Fig. 5, Plate XX, which 1 suppose 
to be a middle metatarsal of Palaeosyops. It was found by L)r. Corson in 
the vicinity of Fort Bridger. It resembles the correspondibng one ol" the 
tapir, but is shorter and of more slender proportions. It has about the size 
of the lateral metatarsals of the tapir. 

Figs. 6 and 7, Plate XX, represent a tirst and second phalanx, probal)ly of 
Palaeosyops. The specimen of the first was obtained by Dr. Carter on Henry's 
Fork of Green River; the specimen of the second was found near Fort 
Bridger. 

A specimen of a metacarpal, which I suppose to l)clong to Palseosyops, 
was obtained by Dr. Corson at Grizzly Buttes. It has about the same length 
as the middle metatarsal attributed to Palseosyops, but is somewhat wider. 
If it corresponds with the second of the series of four toes of the fore foot 
of the tapir, it exhibits a corresponding reduction in relation \vith the con- 
tiguous toes that the middle metatarsal does to the others of the hind loot. 

Palteosyops major. 

A larger species of Palseosyops is apparently indicated by some fragments 
of large bones obtained by Dr. Carter at Grizzly Buttes and other localities 
in the vicinity of Fort Bridger. Several of the specimens consist of ])ortions 
of limb-bones, but too much mutilated either for description or representa- 
tion. Even the best specimen, consisting of a fragment of the lower jaw, rep- 
resented in Fig. 8, Plate XX, is barely more than sufficient to render it 
[)robable that it pertained to Palaeosyops. The jaw-specimen is furthermore 
in some degree abnormal in form, due to inflammation or some other affection 
connected with the second molar tooth. The bone outside the position of 
the latter is much swollen, and the alveolar border is hollowed out and irregu- 
lar. The alveolus is also filled with the clay matrix, so that the tooth \\as 
perhaps lost before the death of the animal. In its proportions, the jaw, in a 
normal condition, would appear to be of more robust character than in 
Palceosyops pabidosus. In its present state, the base is more convex fore and 
aft than in the latter, and the alveolar border more ascending posteriorly. 

The remains of the molar fangs at the entrance of the alveoli appear to 
indicate teeth of the same form and construction as in Falccosyojjs paludosus^ 



46 

for whicli reason (he fragiiient was rei'erred t(j the same genus. The true 
molars appear to have occupied a space of 4| inches, tlioiigh this is probably 
somewhat exaggerated, as the interval occupied hy the last intermediate molar 
appears proportionately somewhat too large. The crown of the last molar, 
which was clearly trilobate as in Pal(zosyoj>s paludosus, had an antero-posterior 
diameter of 2 inches. 

The former existence of a larger species than Palceosyops paludosus, and 
probably the same as that indicated under the name at the head of the present 
chapter, is apparently confirmed by more characteristic .materials placed at 
. my disposal by Dr. Carter in my recent visit to Fort Bridger. One of the 
best preserved specimens consists of the greater part of the left ramus of the 
lower jaw, containing six molar teeth, as seen in Fig. 1, Plate XXIII. The 
jaw is considerably more robust than in those referred to Palceosyops paludosus, 
though not to the degree I supposed from a view of the diseased specimen 
above described. At the side it is more rounded toward the base, and is more 
convex in a curving line from the root of the coronoid process beneath the 
true molars, and is more bent inward and convex from the position just indi- 
cated toward the technical angle of the bone. Rugosities of the surface in 
several positions indicate stronger attachment of the soft parts, in accordance 
with the greater bulk of the animal, than in Paloiosyops imludosus. 

The true molars have the same form and proportions as in the species just 
named. Trifling differences appear to be dependent only on a difference in 
the robust character of the species. The external basal ridge is slightly bet- 
ter developed, as is also the case with the median I'idge, descending on the 
inner slope of the external lobes of the crown. The back lobe of the la.st 
molar is also rather better developed, and incloses a shallower fossa on its 
imicr side. 

The first premolar, situated immediately behind the canine, is inserted by 
a single fang, and is separated from the second premolar by a hiatus about a 
third of an inch in extent. Below the hiatus, the jaw externally presents a 
small concavity. 

The last premolar has the same form as that in the jaw referred to 
P(d(BOsyops paltidosus^ though, from its worn condition, it looks different. In- 
dependent of this, it exhibits no diflerence except that the base in advance 
of llu' anterior lobe is [)n>duc-cd exlcnially in a strong ridge. 



47 

The tliirtl prcinohir also is like that of PalfEosyops pnludos/zs, c\ce[)i'\ug that 
it exhibits a tendency to the prudiiclion of a ba.sal ridge nut evident in 
the former. 

The second premolar, not present in the jaw-specimen of Pakeosyops 
puludosus, is a reduced form of the tooth behind it. A portion of the canine 
alveolus retained in the specimen indicates a tooth of moderate size in com- 
parison with the size of the jaw itself 

* Another series of lower molar teeth, attached to small jaw-fragments, and 
represented in Fig. 2, Plate XXIII, also appear to me to be referable to 
Pul(Bosyops major notwithstanding certain diiferences presented b^' the pre- 
molars. The teeth are considerably more worn than in the preceding speci-. 
men ; most of the summits of the constituent lobes of the crown of the mo- 
lars and last premolar being so worn as to exhibii islets of exposed dentine. 
The second molar is most worn, and presents on the summits of the outer or 
principal lobes broad, depressed, shield-shaped tracts of dentine. 

The molars have the same constitution as in the preceding specimen. The 
last one is smaller, but the others arc nearly of the same size, except that the 
iirst one is thicker, especially at its fore part, and is therefore of more uniform 
diiimeter. The basal ridge of the anterior two molars is better developed 
externally than in the former specimen. In the first molar the anterior lobe, 
being proportionately rather better developed than in the corresponding tooth 
of the previous specimen, its anterior ridge curving inwardly, is stronger, and 
it embraces a more conspicuous fossa. 

Tlie last premolar differs somewhat in proportions from that of the former 
specimen, but is otherwise nearly the same, except so far as it is altered in 
appearance from being more worn. It is of less breadth fore and aft, and 
is thicker, and it docs not present the ridge at the fore part of the base, 
externally, of the anterior lobe, being in this respect more like the corre- 
sponding tooth in the jaw-specimen of Pulaosijops paludosus. 

The third premolar differs from that of the former specimen very much in 
the -same manner as the succeeding tooth. The crown is of less l)readtli fore 
and aft, and is thicker. It has exactly the same constitution, but looks differ- 
ent on account of its more worn condition, its difference of proportion, and 
from the absence of a basal ridge occupying the fore part of the crown, exter- 
nally, in the former specimen. 

Comparative measurements of the teclh and jaws of the specimens just 



48 



referred to Pulccosyops major, and tlic jaw-specimen, witli teeth, of P. palu- 
dosus, are as follows : 



Depth of jaw at middle of last molar 

De'lith of jaw at middle of last premolar 

Thickness of jaw below interval of last two molars 

Thickness of jaw below third premolar 

Distance from canine alveolus to back of last molar 

Length of the complete molar series 

Length of the molar series, excluding the first premolar 

Length of the molar series, exclnding the first two premolars 

Length of the premolar series 

Length of the true molar series 

Breadth of second premolar 

Thickness of second premolar 

Breadth of third premolar 

Thickness of third premolar ... 

Breadth of fourth premolar 

Thickness of fourth premolar 

Breadth of first molar ". 

Thickness of first molar 

Bieadth of second molar 

Thickness of second molar 

Breadth of third molar . - 

Tbickness of third molar 



PaliBosyops 
major. 



Lines. 
37 
26 
IG 
14 
92 
90 
82 
72 
38 
53 

9 

5 

8^ 

7 
13i 

9 
ICi 

m 

24 
13i 



Lines. 



08 
51 



8 
G 
8a 

13i 

ICJ 

wl 

22 
12 



Paliposyops 
paludosus. 



Lines. 
32 
23 
13 
lOi 
?77 



64 
4GJ 



8.i 

5i 
9 

6:} 

12i 

s" 

15 

9i 
19 
10 



Some additional specimens, found by Dr. Corson iu the buttes of Dry 
Creek Caflon, appear to belong to tlie larger Palaeosyops. These consist of 
some upper tectli, comprising a canine, a second and last premolar, and the 
second and third molars. 

The latter are represented in Figs 10, 11, Plate XXIII, and they agree 
in character witli the corresponding smaller teetli described nnder the head " 
of Pu/cBO-si/ojys paludosus. They are but slightly worn at the summits of the 
lobes of the crown, and the enamel is conspicnonsly wrinkled. 

The last premolar, represented in Fig. 9, of the same plate, likewise agrees 
with the corresponding tooth described umler the head of PalcBOstjops palu- 
dosus, except that it is of larger size. The tooth is Init slightly worn, and 
e.xhil^its a much less wrinkled condition of the enamel than the true molars. 

The second premolar, represented in Fig. 8, resembles in form that of the 
second series of specimens of upper molar teeth, described under the head of 



40 



I'lihvosijops paludo.'iu.s. It is larger, less worn, and has, comparatively with 
the true molars, smooth enamel. 

An upper canine tooth, i-epresented in Fig. 7, is of less size than that in 
the facial specimen of PalceosyojJS paludosus^ the reverse of the condition in 
lliis respect of the molar teeth. The canine tootii resembles, in its form an<l 
proportions, the corresponding weapon of the bear. The crown is of mod- 
erate length, and cnrved conical. It is provided with a subacute ridge in 
front and behind, defining the smaller inner face from the outer one, and has 
the base slightly thickened internally. The enamel is nearly smooth, and is 
somewhat worn on the anterior face. The fang is considerably longer than 
the crown, less curved, and is in some degree gibbous. 

A lateral incisor, represented in Fig. 5, Plate XXIV, is a strong tooth, 
somewhat resembling that of the tapir. The crown is conical, with the inntu- 
and outer faces defined by ridges, with the base thickened in front, and u 
strong basal ridge internally. The fang is about twice the length of i\\£, 
crown, and is somewhat sigmoid. 

The measurements of the upper teeth of PahEosyops major, in comparison 
with those of P. paludosuSy are as follows : 



Autero-posterior diameter of last upper molar . . 

Transverse diameter of last upper molar 

Autero-posterior diameter of secoud upper molar 

Transverse diameter of second upper molar 

Antero-posterior diameter of last premolar 

Transverse diameter of last premolar ' 

Autero-posterior diameter of second premolar . . . 

Transverse diameter of second premolar 

Leugtli of crown of cauiue 

Autero-posterior diameter of base of cauiue 

Transverse diameter of base of canine 

Diameter of fang of cauiue 

Length of crown of lateral incisor 

Diameter of base of crown of incisor 

Diameter of fang of incisor 



Palu'osyoiis, 


Pahcosyops 


major. 


paluilosus. 


Lines. 


Zincs. 


18 


18 


19 


IGa 


19 


10 


IS 


10 


lOJ 


9 


12.i 


11 


9 


8 


7.i 


1 


]S 




10 





11 




ru 


10 




7 




8 





A small collection of teeth belonging to the larger Palaeosyops was obtained 
by Dr. Carter in a butte ten miles distant from Dry Ci'eek Canon. Amoiiir 
llic specimens there is a scries of upper premolars, froin the second to the 

7 G 



50 

last, inclusive, ir[)i-cs('iitctl in Fii^. 12, Plate XXIII. The crowns of the 
teeth are worn, and also somewhat eroJeil, Init not to such an extent as tu 
obscure their characters. 

The last npper premolar agrees \\ ith that previously described and referred 
to Palceosyops major, except that it is of more uniform width. 

The third premolar is a reduced representative of that behind it, i)nt is also 
pro])ortionately of less width transversely. 

The second premolar is like the corresjujuding tooth above described and 
referred to Palaosyops major, but is considerably nari'ower fore and aft. 

A much worn upper true molar, partially broken away externally, is rather 
smaller than the specimen of a second upper molar above described and 
referred to PalcBosyops major. It sufficiently accords with it to be the first 
of the series of true molars. 

Another specimen consists of a mutilated canine, intermediate in size to 
the more perfect one above described, and the larger one, contained in the 
facial specimen described under the head oi' Pa/ausj/ops j)aludosi/s. The fimg 
toward the extremity is more curved than in either of the other specimens. 

An upper lateral incisor was about the size of the one previously described, 
l)ut has a stouter fang. Its crown, Ijroken toward the point, is deeply \\orn 
away internally. 

Another incisor, a lower one, is represented in Fig. 15, Plate XXIII. It 
has a short, conical crown, with a strong basal i-idge posteriorly. 

The measurements of the specimens are as follows: 

Liiu's. 

Antero-posterior diameter of upper true molar, estimated 10 

Transverse diameter of upper true molar 18 

Antero-ijosterior diameter of upper last premolar S'} 

Transverse diameter of upper last premolar 1-| 

Anteroposterior diameter of upper third pi-einolar 8 

Transverse diameter of upper tiiird premolar. 11':^ 

Autero-posterior diameter of upi)er second premolar 7 

Transver.se diameter of upper second premolar , 8^ 

Length of fang of canine -^ 

Diameter of fang of canine 12 

Length of fang of npper incisor 2-! 

Diameter of fang of u[)per incisor 7i 

Length of crown of knvvr incisor 

Antero-posterior diameter of lower incisor 

Transverse diameter of lower incisor ■ 5 

An important and instructive specimen pertaining to /'^/Zews/yo^w /«(//o/- is 
reiiresenfed in Fig. Iti, Plate XXIII, and Fig. 1, Plate XXIV. It consists 



51 

of a cranium, discovered by Dr. Carter in the hutles uf Dry Creek Canon. 
The specimen was broken into many pieces, but tliese have been united so 
as to give us a good idea of the shape and construction of tlie cranium. This 
is of remarkable form, and exhibits more resemblance to that of a bear flian 
to that of its nearer relative the tapir. 

The forehead, as seen in the upper view of the cranium, Fig IG, Plab^ 
XXIII, forms a long triangle, with the apex prolonged backward and expanded 
at the summit of the occiput. Its fore part more abruptly widens as it exten<ls 
outwardly upon the conspicuous postorbital processes. Its surface from the 
apex forward is strongly convex, but approaching the muzzle between tlie 
position of the postorbital processes it becomes in the same direction con- 
cave. Transversely it is nearly straight between the boundaries of the tem- 
l»oral ibss;e, but is convex between the postorbital processes. The lalter 
are strong and unusually prominent, trihedral, hook-like projections. Their 
upper acute border forms the anterior extension of the temporal boundary 
from the forehead. Their supra-orbital margin curves from the tiice Jiack- 
ward and outward to the point. Their anterior or facial surface is depressed 
or concave. 

The postorbital process preserved in the specimen is broken at the end, 
but is there so narrow as to make it appear that it did not meet an ascending 
process from the malar l)one as to Ibrm a postorbital arch. The strongly 
arched supra-orbital border is directed outward with a moderate backw ard 
inclination, indicating a more forward direction for the orbit than in the tapir 
and rhinoceros. 

The short postorbital eminence of the malar bone in tlie facial sjiecimen 
referred to Falatosyops paludosus, and represented in Fig. 51, Plate XVIII, 
would also indicate that the orbits were oj^en behind in Palset)syops, notwith- 
standing the great length of the postorbital process of the frontal in the 
specimen under consideration. 

The l)ase of the muzzle, or the face, between the position of the orbits is 
broad and convex. 

, Tiic specimen exhibits no evident traces of the sutural conjunctions of the 
parietals, frontal, the maxillaries, and the nasals. 

The cranial crest separating the temporal fossa; is exceedingly short com- 
pared with that of the tapir. It is formed by the approach of the temporal 
l)oundaries, which appear in this position as two ot)tusc ridges squeezed 



52 • 

tugethcf, and leaving between thcni a narrow groove extending from the tore- 
head to a transverse concavity at the summit of" the occiput. 

The temporal fossas are of huge proportions, and appear even to exceed those 
of the greatest living carnivores, as the lion and the Bengal tiger. The zygo- 
mata are as prominent as in these, but are proportionately of greater strength, 
being both deeper and thicker. Excepting in their greater extension out- 
wardly from the posterior root, as in the latter animals, in^ their sigmoid direc- 
tion downward and forward they are more like those in the tapir. Their 
outer surface is convex, and is directed obliquely upward. 

The temporal surface at the side of the cranium, and extending on the 
zygomatic root, forms a deep excavation or concavity slightly overhung by the 
upper part of the temporal ridge. It exhibits a comparatively feeble swelling 
aljout the position of the squamous suture, but much less conspicuous than that 
in the tapir. The great hollow of the temporal surface is in striking contrast 
with the sweUing of the corresponding surfiice in the great living carnivores, 
and \yhile it is expressive of an equal if not greater extent of powerful muscles, 
it is further expressive of a proportionate decrease in the capacity of the cra- 
nium and therefore of a much smaller brain. 

The cranium is constricted at the sides at the lower ])art of the temporal 
fossse, just in advance of their middle, and the fore part, independent of tlnj 
extension of tlie zygomatic roots, appears nearly as wide as tiic back part. 

The squamosals are large, and reach half way up the temporal surface. A 
conspicuous group of neuro-vascular foramina occupy their upper back part, 
including the contiguous part of the parietals. The occiput is wider than 
high, is strongly concave above, but at the lower part slopes backward to the 
margin of the occipital foramen. Its sides below are bent forwarti, as in the 
tapir, and the lateral borders above, as in the latter animal, are produced in 
wing-like expansions. The basal angles of the occipital triangle arc formed 
by comparatively short, wide processes, composed of the conjoined paramas- 
toid and post-tympanic processes. These extend iToni within the position of 
the occipital condyles and reach outwardly a considerable width beyond them, 
but do not project much below the root of attachment of the condyles. The 
occipital condyles ;;re of greater proportionate width but less depth than in 
the tapir or the bear; and they project from the occipital surface backward 
more than in either of those animals. The occipital foramen is transversely 
oval. 



53 

The general plane of tlu! uceipul is intermediate in ils degree of inelinatidii 
to that of the tapir and our large caruivores,, and is indeed nearly vertical. 
The occipital condyles project posterior to the general surface, and thus form 
tlie most pi-ominent portion of the occiput, whereas in the tapir, bear, and cats 
the summit of the occiput is most prominent backward. 

The articular surfaces of the condyles extend forward on the basi-oceipital, 
and approach quite near each other, as in the bear. 

A large vencnis foramen occupies the course of the occipi to-temporal suture, 
about the center of the lateral plane of tlie occiput. 

The auditory archway is high and narrow compared with that of the tapir. 
It is widest above and has its sides converging inwardly. 

The post-glenoid tubercle, compared with that in the tapir and ijcar, is very 
thick and strong. It is broad and mammillary, and is directed obliquely out- 
ward and projects downward below the post-tympanic process. The base of 
the cranium is very broad compared with that of the tapir, and in this resi)cct 
is more like that of the great carnivores. 

The basi-occipital is broad and thick. It narrows forward from the posi- 
tion of the paramastoid processes. Its sides are concave from before back- 
ward, slope strongly from the upper edge toward each other, and are sepa- 
rated by a median carina which expands behind and ends in front in a prom- 
inence. The basi-sphcnoid, completely co-ossified with the basi-occipital, 
appears as a narrowed extension of this, and is transversely convex. 

Large vacant spaces, occupied with the matrix of the fossil, are situated 
below the position of the petrosals. The tympanies are lost. 

The glenoid articular surface is broad and nearly horizontal above, and 
extends obliquely downward, outward, and backward on the robust post- 
glenoid tubercle. 

The anterior condyloid foramen is situated about three-fourths of an intdi 
in advance of the occipital condyle. 

The root of the pterygoid process is pierced with an ali-sphenoid canal, and 
the oval foramen occupies a position just above it. 

Measurements of the cranium are as follows: 

Length of crauium from tbe C0Qca,vity at the summit of the occiput to a 
line between the post-orbital processes, following- the curvature of the 
forehead 9 inches. 

Breadth acress the face, following the convexity between the ends of the 

post-orbital processes S^ inches, 

Distance between the orbits across the face above inches. 



54 

Thickness of tlie short ciauiul crest seiKiratiiii;- the temporal l'oss;i' poste- 
riorly 3 i"*^li 

Breadth of temiioral foss;e from the occipital border to the end of the i)OSt- 

orbital process 9 inches. 

Vertical extent in advance of zygomatic root •. 5 inches. 

lireadth of cranium outside of zygomata 11 inches. 

Height of occiput . . 53 inclaes. 

Breadth of occiput at post-tympanic processes (ii inches. 

Breadth of cranium at ends of post-glenoid processes 8 inches. 

Transverse diameter of occipital foramen ; . . 23 lines. 

Vertical diameter of occipital foramen, estimated ■. IG lines. 

Breadth at occipital condyles together 47 lines. 

Depth of occipital condyles IS linos. 

Breadth of occii)ital condyles 19 Hues. 

Width of basi-occipital at anterior condyloid foramiua. 18 lines. 

Width of basi-occipital at conjunction with basisphenoid 15 Hues. 

Distauce between glenoid articular surfaces 51 lines. 

An upper-jaw fragment, from the same individual as the cranium just 
described, contains the last two molars, of wliicli the pemdtimatc one is re[)- 
resented in Fig. 3, Plate XXIV. This tooth closely resembles the corre- 
sponding one of the same species represented in Fig. 10, Plate XXIII, and 
also that of Paloiosijops paludosus as represented in Figs. 3 to 5, Plate IV, and 
Fig. 9, Plate V. The last molar, as fai* as it is preserved, likewise resembles 
the corresponding tooth represented in the same places. The inner part of 
the crown presents a single conical lobe. 

The infVa-or])ital Ijorder forms a thick, obtusely rounded ledge projecting 
obliquely forward on the face. In Palaosyops faludomH the corresponding 
ridge presents an acute anterior edge defining it from the facial surface beneath. 
The outer ])art of the thick infra-orbital ridge rises in a short, l)lunt, conical emi- 
nence or postorbital process. The orbital floor is concavely depressed within 
the prominent margin, and forms a long, triangular platform terminating 
beiiind in the thick posterior boundary of the maxilla. 

The measurements of the specimen are as follows: 

Lines. 

Space occupied by the last two molars 32 

Breadth of second molar • 20 

Width of second molar 20 

Height of anterior orbital margin from the molars 20 

Fragments of both sides of the lower jaw with all the teeth broken away, 

except portions of the last molars, also accompany the preceding sjiecimens. 

The best preserved fragment partially restored from the corresponding ]>or- 

li(ni of the opposite side is represented in Fig. 4, Plate XXIV. It agrees in 



T 



DO 



i'onn niid pi'dpoiiioiis willi the same jxirlioii ol' \\\c jaw in Palceoxi/o/is pnUi- 
(losus, excei)tiiig that the masseteric fossa- is nuicli deeper. The preser- 
vation of the angle of the jaw, not retained in any of thi^ previous specimens of 
Palaeosyops, permits the determination of its character. It presents a nearly 
serai-circular border projecting moderately below ti)e base of the bone, and in 
a less degree posteriorly. Toward the base it is somewhat bent inward. 

The last molar, in a restored condition, of the natural size, is re|)resente<l 
in Fig. 14, I'late XXIII, but, unfortunately, the artist has made its tliickness 
in front proportionately too great. 

The measurements of the specimen are as t()llows: 





Palaiosyops 
uuijor. 


Paloeosyopa 
liahulosus. 


Distance from last molar to back border of jaw 


Lilies. 
01 
■72 
35 
10 
22 
13 

Hi 


Livcfi. 
4!) 


Deptli from coiidvle to bottom of angle 




I)(^i)tli of iaw bt^low fore nart of last uiolar . . 


30 


Tlii(!kiioss of i;iw bolow forp, i>a,rt of List iiiohir . . - 


14 


Tjveadtli of last molar tooth 


10 


Wkltb at fore part of last molar tooth 

Width at middle part of last molar tooth 


lOi 



Fragments of another jaw similar to the above, and presenting the same 
comparatively deep masseteric tbssa, were found by Dr. Corson at Grizzly 
Buttes. 

Fig. 2, Plate XXIV, represents a mutilated facial portion of a skull appar- 
ently referable to PalcBosyops major. The specimen was found on one of the 
buttes of the Bridger formation by a Shoshone Indian, and brought to Dr. 
Carter, by whom it was presented to the writer. Though much distorted in 
form, it gives us a fair idea of the shape and construction of a portion of the 
skull of Palseosyops that we had not previously had the opportunity of ex- 
amining. It is crushed in such a manner that the upper part of the face is 
pressed downward and toward the right side, and the orbit has its roof 
brought near to the floor, so that it looks as if it were closed behind l)y the 
presence of a postorbital bridge. 

The specimen shows that the form and construction of the face of Paloeo- 
syops are very similar to what they are in Paleeotheiium. The upper part of 
the face appears to have been directed in a moderately sigmoid course, nearly 
horizontallv from the bottom of the convex forehead to the end of the muz- 



56 



zle. The n;i«ils are large, thick, and strong. Proportionately they exceed in 
length those of the Pal«othere, the rhinoceros, and the tapir. If I mis- 
take not a tiacture for a suture, their posterior extremity reaches as ftir as the 
position of the fore part of the orbits, and their free extremity projects quite 
as much as the jaws. They are strongly arched transversely and are mdre 
abruptly rounded and thick at the lateral 'borders. They gradually narrow 
tljrward and terminate in a blunt extremity, which is nearly straight but 
rounded at the outer angles. Posteriorly, they include a deep and wide an- 
gular notch, which receives a corresponding angular prolongation of the 
fVontals. 

The lateral nasal notch resembles that of the rhinoceros, Init is propor- 
tinnately of greater depth, and in this respect also resembles that of the 
Palseothere. Its exact extent cannot be determined on account of the mu- 
tilated condition of the specimen. . 

The upper jaw in its form and proportions is nearly like that of the Palaso- 
there. It is of greater proportionate depth below the orbit, and exhibits a 
greater swell at the border of the nasal notch, due to the greater size of the 
canine teeth. The infra-orbital foramen is large, and is'situated over the 
position of the last premolar. The hard palate is flat along the middle an- 
teriorly. Its posterior part is destroyed in the specimen, so as to prevent 
the determination of its extent. 

The incisive foramina appear to be comparatively small and widely separated. 
They appear also to be circular, and continuous with grooves descending for- 
ward to the incisive alveoli. 

The teeth form a series as unbroken nearly as in Anoplotherium. They 
are all mutilated in the specimen, but the crown of the last premolar, and the 
molars are sufficiently well preserved to exhibit the characteristics of Palseo- 
syops as already described. 

Measurements of the specimen, for the most part approximative on account 

of its distorted condition, are as follows : 

Length of jaw from back of last molar to front of incisive alveoli 9 inches. 

Length of face from the anterior orbital margin to the end of the nose. . . 7 inches. 

LcngtL of the nasals in the median line 5 J inches. 

Breadth of the. nasals together at their middle 3^ inches. 

Length of space occupied by the molar series Csjr inches. 

Length of space occupied by the true molars 3^ inches. 

r.readtli of last premolar ; 9 lines. 

Width of last premolar , 12 lines. 



57 



Breadth of lirst molar .' _ . 14a liues. 

Width of hrst molar 14j^, ijups. 

Breadth of secoud molar Kj" ijucx. 

Width of second molar k; lines. 

Breadth of last molar 19j lines. 

Width of last molar 18 liues. 

Width Of palate betweeu canines 2S lines. 

Width of canine alveoli 9 lines. 

PALyEOSYOPS JUNIUS. 

Dr. Carter recently sent the writer several small fragments of the rit^ht 
side of a lower jaw, togetiier with a sketch of a larger fragment of the left 
side, containing the last premolar and the succeeding molars. The s|)eci- 
mens were obtained from the Bridger beds, and appear to indicate a small 
species of Palasosyops, though it is not improbable that they pertain to a 
small variety of P. paludosus. 

The parts agree closely with the corresponding parts of the lower jaw and 
teeth of the latter, except in size. They have been viewed as representatives 
of a species with the name of Fal<eosyops Junius. 

The measurements of the teeth in comparison with those of P. indudosus 
are as follows : 



Space occupied by the last premolar and molars 

Space occupied by the molars > 

Breadth of last premolar 

Thickness of last premolar 

Breadth of first molar 

Breadth of second molar 

Breadth of third molar 

Thickness of third molar at middle 



PiiiiEosyops 


Palyosyops 


JUUIUS. 


paludosus. 


Lilies. 


Lines. 


48 


55 


39i 


■10 


8 


9 


54 


«i 


10 


12^ 


12 


15 


17 


19 


7 


9i 



LIMNOHYUS. 

This genus was originally named by Professor Marsh, in a communication 
published in the American Journal of Science for August, 1872, and was 
applied to Paleeosyops under the misapprehension that this genus had not 
been distinguished by the possession of one or two cones to the inner part of 
the crown of the last upper molar tooth. As it was as cleai-ly demonstrated 
as the nature of the specimens would admit, that the last upper molars of 
8 G 



58 

Palasosyops possessed l)iii a single cone to llic imier part of the crown, the 
name subsequently proposed by Professor Marsli on account of this character- 
istic was untenable. Under these circumstances, though I previously viewed 
the difference as simply specific, I would adopt the generic nameof Limnohyus 
lor those forms of Pakeosyops, as recognized by the general constitution of 
the teeth, in which the last upper molars have two cones to the inner part of 
the crown. 

Fig. 13, Plate XXIII, represents an upper molar tooth, apparently the fii'st 
of the series of true molars, resembling in form the corresponding teeth of 
Palceosyops paludosus. Tlie enamel of the tooth is, however, comparatively 
smooth, a condition which is clearly independent of its age, as the tooth is 
but moderately worn. As a considerable degree of variation is observed in 
the extent of wrinkling of the enamel of the teeth of Palceosyops imludosus, 
independent of wearing, it is not improbable the specimen may pertain to 
an individual variety of the same, though it prol)ably niay indicate anotiier 
species. 

The specimen was found by Dr. Corson in association with the large tusks 
originally referred to Uintamastix atrox, described in a later chapter, and 
represented in Figs. 1 to 3, Plate XXV. 

Since wi-iting the description of the smooth, enameled molar tooth, Pro- 
fessor Marsh, who has inspected the specimen, informs me that it pertains to 
the same animal he has described under the name of Palaosyops laticeps, 
(Am. Jour. Sc, Aug., 1872.) As this is stated to have four lobes to the 
crown of the last upper molar, for reasons already given, it would belong to 
the genus Limnohyus. 

Fig. 8, Plate XXIV, represents the crown of an ujiper molar tooth, which 
was found, together with some small fragments of other molars, both upper 
and lower, by Dr. Corson on the buttes "of Dry Creek Cailon. The specimen 
I supposed to belong to a small s])ecies of Pateosyops, and so referred it, 
under the name of P. hiimUlfi, in a letter to the Academy, published in 
its Proceedings for July 30, 1872. Under the impression that it was 
perhaps the last tooth of the series, in view of the distinction suggested by 
Professor Marsh between Palaeosyops and Limnohyus, I subsequently 
ascribeil it to the latter. Professor Marsh informs me that he has a number 
of specimens which lead him to regard the tooth as pertaining to the tempo- 
rary series of Palaeosyops. 



59 

HYRACHYUS. 

An extinct genus of odd-toed pachyderms, under the above name, was 
originally inferred from specimens of fossils obtained during Professor Hay- 
den's exploration in Wyoming, in 1870. One of the specimens, represented 
in Fig. 11, Plate II, consists of the greater portion of a ramus of the lower 
jaw, without teeth, found on Smith's Fork of Green River. The other speci- 
men, represented in Fig 12, consists of a lower-jaw fragment, witli several 
teetli, of a young animal, from Black's Fork of Green River. 

Hyrachyus is closely related with the extinct tapiroid genus Lophiodon, the 
remains of which belong to the early Tertiary formation of Europe. In a less 
degree, also, it is related with the rhinoceros-like Hyracodon of the Mauvaises 
Terres of White River, Dakota. Among living animals, it is most nearly 
allied to the tapir, and more remotely with the rhinoceros. 

The dental series of the true Lophiodon, if the L. isselense of Issel, 
France, be viewed as the type of the genus, or of Tapirotherium, as it had 
been previously named by De Blain.'ille, consists of three iucisors, a canine, 
three premolars, and three molars. The living tapir at maturity has one pre- 
molar more to the upper series. 

In one species of Hyrachyus at maturity there are four premolars to the 
series above and below, as in Hyracodon. Apparently, in a second species 
there are four premolars in the upper series, and three in the lower, as in the 
tapir. 

The last lower molar of Lophiodon has a trilobate crown. In Hyrachyus, 
as in the tapir, it has a bilobed crown. 

The crowns of the lower molars are intermediate in character with those 
of Lophiodon and Hyracodon. 

The upper molars of Hyrachyus closely resemble those of Lophiodon. In 
both genera the upper back two premolars have a single lobe to the inner 
part of the crown representing the inner pair of lobes of the crowns of the 
succeeding molars in a connate condition. In Lophiodon a ridge proceeds 
from the inner lobe of the crown of the premolars mentioned to the antero- 
external lobe. In Hyrachyus, in the corresponding teeth, a pair o£ ridges 
proceed from the inner lobe of the crown to both the outer lobes. 

The lower jaw of Hyrachyus has nearly the form and construction of that 
of the tapir. 



60 

Hyrachyus agrarius. 

This species, originally inJicatcd aiul named from tlie specimen repre- 
sented in Fig. 11, Plate II, consisting of a ramus of the lower jaw without 
teeth, we have now the opportunity of illustrating by many well-preserved 
and more characteristic specimens. Most of these were collected by Dr. J. 
Van A. Carter, during the last summer, on Henry's Fork of Green River, 
near Lodge-Pole Trail, at Bridger Butte, and other localities in the vicinity of 
Fort Bridger, Wyoming. A few others were detained by Dr. Joseph K. 
Corson, from Grizzly Buttes, Wyoming. 

The specimen represented in Fig. 12, Plate II, being one of those upon 
whicli the genus Hyrachyus was originally proposed, was referred to another 
species from the former one, with the name of Hyrachyus agrestis. This I now 
regard as of the same species. The specimen, a lower-jaw fragment, belonged 
to a young animal, which still retained its temporary teeth. Of these, the 
fossil contains the first premolar, the fangs of the succeeding two, and the 
molar tooth. Behind this the first molar of the permanent series is inclosed 
within the jaw. 

Professor Marsh has described remains apparently of the same animal 
under the name of Lophiodon Bairdianus. The specimens, which he observes 
are among the most common of the mammalian fossils of the Wyoming Ter- 
tiary, were found at various localities near Fort Bridger, and also on the 
White River, in Eastern Utah. 

The dental series of Hijrachyus ngrar'ms, in the mature condition, consists 
of three incisors, a canine, four premolars, and three molars, in both jaws. 

A well-preserved series of upper molar teeth, considerably worn, is repre- 
sented in Figs. 9 and 10, Plate IV, from a specimen discovered by Dr. Car- 
ter near Lodge-Pole Trail, about eleven miles from Fort Bridger. Fig. 11, 
of the same plate, represents an upper second molar, which was obtained by 
Dr. Carter on Henry's Fork of Green River. 

Of the upper molars, or true molars, the middle one is the largest, and the 
others are nearly equal in size. Four principal lobes enter into the constitu- 
tion of iheir crown, which is inclosed by a basal ridge, except externally, and 
at the. most prominent portion of the inner lobes internally. Of the outer 
lobes, which are conjoined, the posterior is the wider and is pyramidal; the 
anterior is the more prominent externally and is conical. Tliis is also strength- 
ened in front by a large conical buttress continuous with the comparatively 



61 

wide anterior l)asal ridge of the crown. In tlic last molar the jiosterior of 
the outer lol>cs is proportionately less well developed than in the molars in 
advance. The inner lobes of the crown are conical internally, and are extended 
obliquely outward so as to form ridges continuous with the fore part of the 
outer lobes. The oblique valley separating the inner lobes is closed exter- 
nally by the conjunction of the outer lobes. A wide, angular recess occupies 
the interval of the posterior lobes of the crown and the posterior basal ridge. 

In the unworn or moderately worn condition of the molars, as seen in Fig. 11, 
Plate IV, a narrow but conspicuous ridge or fold is observed projecting from 
the antero-external lobe into the median valley of the ci-own. In the 
worn condition of the molars, as seen in Fig. 10, c to g, they exhibit a 
Iract of exposed dentine extending along the summits of the outer lol)es 
including the abutment in front, and prolonged inw^ardly in two pouch-like 
extensions upon the summits of the inner lobes. 

The upper premolars not only exhibit from behind forward a successive 
diminution in size, but also a reduction to greater simplicity. The latter con- 
dition is induced through connation and disappearance of constituent elements 
as they are observed to exist in the back teeth. Thus if we compare the 
back two premolars, Fig. 10, c, d, with the molars behind, it will appear tliat 
the most striking difference is due to the connation internally of the inner 
lobes. From this arrangement the premolars appear to have a single loi>e to 
the inner part of the crown, from which a pair of ridges proceed to join the 
outer lobes. A central pit represents the median valley opening internally in 
the crown of the molars. The basal ridge extends around the inner part of 
the crown. 

The abutment so conspicuous at the antero-external angle of Ihc crown of 
the molars is successively reduced forward in the premolars and disappears in 
the anterior two. 

In the crown of the second premolar. Fig. 10, h, the outer lol^es are more 
connate than in those behind, and the inner lobe appears more isolated from 
the absence of the intervening ridges. 

The crown of the first premolar, Fig. 10, a, about half the size of^that of 
the tooth behind, is conoidal with an oval base. For the most part it is 
homologous with the outer lobes of the other premolars in a completely con- 
nate condition. A small offset internally is a ruiliment of llie inner lobe of 
Ihe succeeding premolar. 



62 

A hiisal ridge exists at the outer back part of the crown of tlie seconcl pre- 
molar, and, less produced, exists in the same position in the third. No ridge 
occupies the inner prominence of tlie inner lobe of the second premolar. 

A specimen of an upper left last premolar, found at Grizzly Buttes by Dr. 
Corson, is represented in Fig. 12, Plate IV. It is larger than in the entire series 
of Fig. 10 and is less worn. It exhibits a basal ridge externally interrupted 
at the middle ; and internally the ridge is also interrupted or nearly obsolete 
at the middle. The posterior ridge or fold between the inner and postero- 
external lobes, though smaller, is more defined from the lobes than the ante- 
rior I'idge. The latter appears rather as a pi'olongation of the inner lobe to 
the fore jiart of the base of the antero-external lobe. The posterior ridge has 
the appearance of an introduced piece defined from the lobes by consti'ictions 
or grooves. The arrangement is badly represented by the artist; nor is it 
obvious if it existed iii the corresponding more worn tooth of the series (jf 
Fig. 10. 

In a much mutilated specimen, obtained by Dr. Corson at Grizzly Buttes, 
containing the remains of the last two premolars and succeeding two premo- 
lars, the basal ridge is better developed at the inner part of the crown than 
in any of the preceding. The last premolar exhibits the same condition of 
the posterior ridge intervening to the internal and postero-external lobes of 
the crown as that described in the isolated tooth. The same tooth, barely 
worn, exhibits the summit of the inner lobe of the crown slightly divided into 
two points, so that it presents a less degree of connation than in the preceding 
specimens. 

The upper molars and premolars, except the first one, are inserted by three 
fangs, of which the inner one is a connate pair; the connation being most 
complete in the premolars. The first premolar has two fangs. The space 
occupied by the upper molar series is about 3| inches. 

Fig. 13, Plate IV, represents a specimen, found by Dr. Carter, in company 
with the upper molar teeth of Figs. 9 and 10, and evidently pertaining to the 
same individual. The specimen consists of the anterior extremity of the 
lower jaw, retaining the incisive alveoli, the canines, and on one side the four 
premolars. A view of the triturating surfaces of the latter is given in Fig. 
14. Figs. 15 and 16 represent a second molar, and Fig. 18 an incisor from 
(he same individual. 

Fig 25, Plate XX, was drawn from a specimen consisting of the greater 



63 

part, of a lower jaw, including both rami, obtained l)y Dr. Carter, at Bridgcr 
Butte, seven miles west of Fort Bridger. The left ramus contains the pos- 
terior three premolars and the succeeding two molars, of which a view of tiic 
triturating surfaces is given in Fig. 26. 

The lower molars, including the last one, in H)/rachyus agrarius have all 
bi-lobed crowns. These are oblong square, and bounded by a basal ridge in 
Iront, behind, and in a more or less interrupted condition externally. Tlie 
constituent lobes have somewhat curved rectangular summits as in Hyracodon 
and rhinoceros. The summit of the anterior lobe curves forward and inward, 
and becomes continuous with the basal ridge of the fore jiart of the crown. 
As the acute summits are worn, tracts of dentine become exposed 
crossing the teeth. In the progress of attrition the expanding dentinal tracts 
extend in an irregular L-like manner,- and finally the contiguous tracts of each 
tooth become continuous, as in rhinoceros at the same stage of wear. 

The crowns of the premolars present the same essential constitution as 
those of the molars, with the constituent lobes, successively, from behind 
forward, becoming more reduced or rudimental. The posterior lobe l>ecomes 
proportionately more reduced than the anterior, and in the first premolar has 
disappeared. 

The crown of the last premolar resembles those of the molars, with the 
])osterior lobe proportionately more reduced than the anterior one. 

The crown of the third premolar, in the speciinen represented in Fig. 25, 
Plate XX, has the same form as in the last premolar, and is simply reduced 
in size. In the specimen represented in Fig. 13, Plate IV, the tooth looks 
ditferent, from the obfique ridge or summit of the anterior lobe of the crown 
as existing in the former, being contracted in this into a conical and some- 
what more elevated point. This gives such a remarkable diilerence to these 
teeth in the two specimens, that, had they been tbund isolated, without a 
knowledge of their collocation, they would have been attributed to dilferent 
genera of animals. 

The anterior two premolars have an oval crown elevated into a median 
conical point and presenting offsets behind and in front, in which may be 
detected the rudiments of the posterior lobe and anterior extension of the 
anterior lobe of the better developed crowns of the teeth behind. 

All the lower premolars, as well as the molars, are inserted by a pair of 
fangs. The space occupied l)y the lower molar series in several specimens 
ranges from 3 inches and .'i lines io o% inches. 



64 

The inferior canine teeth are quite like those of the tapir in appearance. 
They curve upward and forward, with a slight inclination outward. The 
crown is laterally compressed conical, subacute in front and behind, but worn 
in both these positions in the specimen under examination. 

The upper canines are unknown, unless the specimen represented in Fig. 
17, Plate IV, is one. This vvas found at Grizzly Buttes by Dr. Corson, in 
association with some upper premolars of Hyrachyus ; all of which look as if 
they had belonged to the same individual. The crown of this Sjiecimen of 
an upper canine is short, and worn off to a considerable extent at its fore 
part. It is compressed conical, and lias the inner and outer surfaces defined 
l)y an acute ridge posteriorly. The fang is double the length of the crown, 
and is laterally compressed. 

The incisor tooth, represented in Fig. 18, appears to be the second of 
the series of the lower jaw. It resembles the corresponding tooth of the 
tapir. Its chisel-like crown is worn off at the cutting edge. 

No characteristic portions of the upper jaw of Hyrachyus have come under 
our notice. In one specimen tire infra-orbital foramen is observed to occupy 
a position above the third premolar. 

The lower jaw resembles, in its form and proportions, that of the Hyraco- 
don and the tapir. The anterior extremity, in the construction of the chin, 
the contraction between the position of the canines and molar series, and 
other features, repeats the condition observed in the tapir. A similar wide 
hiatus separates the canines from the molar teeth. The free border of the 
hiatus, upward of an inch in length, is concave fore and aft, and acute. 

The body of the lower jaw is less robust or thick, in relation with its 
depth, than in the tapir. It is also less convex externally, and at the 
base fore and aft. The outer surface, in comparison, appears quite 
vertical. 

The ascending portion of the ramus rises vertically at its fore border, and 
is deeply impressed on the outer surface just back of the latter. 

The condyle projects less externally and more posteriorly than in the tapir. 
Its articular surface is more flat, and in a less degree inclined inwardly. 

In the specimen represented in Fig. 13, Plate IV, five small mental 
foramina are observed, in a row extending from the position of the third pre- 
molar to thtit of the canine tooth. In the specimen represented in Fig. 25, Plate 
XX, a large mental foramen i.s situated below the intervul of the third and 



65 



fourth premolars; and in advance of tliis several small ones exist. In llie 
specimen represented in Fig. 11, Plate II, the mental foramen is situated 
below the first premolar. 

Measurements from several specimens of lower jaws of Hyrachyus agrarius 
are as follows : 



Leugth of space occupied by the molar teeth 

Distance from incisive alveoli to first premolar 

Length of hiatus between canine and first premolar 

Depth of jaw below last molar 

Depth of jaw below last i>remolar 

Breadth of jaw at caniue alveoli 

Breadth of jaw below hiatus 

Length of symphysis 



LiDes. Liues 



25 
13 



14 
12 

28 



42 
24 
13 
IS 
15 
13 
10.J 



Liucs. 



44 



20 
10 



Measurements of upper molar teeth are as follows: 

luchcs. Lines. 

Length of the entire upper molar series 3 9 

Length of series of premolars • 1 8.1- 

Length of series of molars 2 1 ', 



Diameter 
Diameter 
Diameter 
Diameter 
Diameter 
Diameter 
Diameter 



of first premolar . . , 
of second premolar 
of third premolar . . 
of fourth premolar . 

of first molar 

of second molar . . . 
of third molar 




Comparative measurements of two upper last premolars are as follows : 

Lines. 

Fore and aft diameter in both 7 

Transverse diameter in one 8^ 

III the other 9 

Measurements of lower molar teeth are as follows : 



Length of the entii'e lower molar series . 



Length of series of premolars. 
Length of series of molars . . . . 



Lines. 



20 



Lines. 



42 
19 
24 



Lines. 



44 
20 

2U 



9g 



66 



Foro aud aft. 



Diameter of first premolar . . 
Diameter of second premolar 
Diameter of third premolar. 
Diameter of fourth premolar 

Diameter of first molar 

Diameter of second molar . . . 
Diameter of third molar. . . . 



Lines. 

^ 

G 
Gh 



Lines. 



u- 



5^ 
8i 



Transverse. 



IjUK'S. 

2.i 

u 



Tj'uiv 



2i- 

3i 

4 

5 

5 



Hijrackyus agrari>(.s was al:)uut the size of the coininoii collared peccary, 
Dicotyles torquatus. 

HYRACHYUfcj liXIMIUS. 

A .supposed larger species of Hyrachyus lluui H. dgrarius is interred IVoin 
several specimens, consisting of small fragments of a lower jaw with a tooth 
and portions of others. These were obtained by Dr. Carter on Henry's Fork 
of Green River. 

The best and most cliaraeteristic specimen is represented in Figs. 19, 20, 
Plate IV, consisting of a lower-jaw fragment containing the last premolar and 
portion of the first molar much worn. Both the teeth and the jaw agree in 
form with the corresponding parts in Hyrachyus agrarius and differ only in 
size. The specimen also agrees with the" corresponding ])art of Lophiodon 
sufficiently to belong to the same genus, so that until more amjile material is 
discovered it must remain uncertain whether it really i)ertains to Hyrachyus. 

Comparative measurements are as follows : 



H. oxiiiiius. H. ;nrrariii.s. 



Lines. 



Depth of jaw at last premolar 

Thickness of jaw at last premolar 

Diameter fore and aft of last premolar. 
Diameter transversely of last premolar 

Diameter trausversly of first molar 

Diameter transversely of second molar. 



".s. 


Lii 


r.s. 


IS 




^^ 


9 




7 


7 




53 


5.> 




4 


Gi 


• 


5 


7 




51 



Figs. 9, 10, Plate XXVl, represent a tooth recently obtained by Dr. Cai^- 
tcr on the buttes of Dry Creek. It would apjiear, from its proportions, to l)e 
(lii^lcfl lower ])eiinltimate molar of //y)Y?''////WA- czimiu^. It is a nearly un- 



fi7 

worn and perfect specimen, and agrees in its anatomical characters with the 
corresponding tooth of H. agrarlus. The crown measures an inch antero- 
jiosteriorly and 7^ lines transversely. 

The specimens above described indicate an animal about tlie size of the 
common American tapir. 

HVRACHYUS MODESTUS. 

Under the impression that teeth of like form with those of Hyrachyits 
agrarius, from the Bridger Tertiary formation, pertain to the same genns, I 
now view the tooth represented in Fig. 13, Plate II, which I previously 
referred to Lopkiodon modestus, as belonging to Hyrachyus. The specimen 
was obtained during Professor Hayden's exploration of 1870, on Smith's Fork 
of Green River, near Fort Bridger. 

The tooth is a first or second up])er molar, and differs in size and propor- 
tion from the corresponding teeth of Hyrachyus agrarius sufficiently to indi- 
cate a smaller species. The only other diflerence observable, one, however, 
which may prove not to be constant in additional specimens, is in the internal 
surface of the antero-internal lobe of the crown, being strongly wrinkled in- 
stead of being elevated in a single conspicuous fold as in H. agrarius. 

The comjiarative measurements of the specimen are as follows: 

H. agrarius. 




Lilies. 

Diameter fore and aft of second upper molar 7 9 

Diameter transversely of second upper molar Of 10 

Hyrachyus modestus was about a third less in size than H. agrarius. 

Hyrachyus nanus. 

Portions of two lower jaws I have referred to a small species of Hyrachyus 
with the above name. One of the specimens was obtained at Lodge-Pole 
Trail, by Dr. Carter; the other, represented in Fig. 14, Plate II, and Fig. 42, 
Plate VI, was found at Grizzly Buttes, by Dr. Corson. 

In both specimens, which belonged to animals at maturity but not advanced 
in life, the number of teeth in the molar series is six, or one less than in 
Hyrachyus, and the same number as in Lojihiodon and the tapir. The last 
molar, however, has a bilobed crown as in the latter, ))ul the premolars, in 



68 



ihcir less degree of (Icvelopinent in comparison wilh the molars, are more 
like those of Lophiodon. 

The suppression of an anterior premolar may jierhaps he regarded as a less 
important generic character than the others which have been indicated as 
separating Hyrachyus from Lophiodon and Tapirus. Under the circum- 
stances, notwithstanding the reduction in the number of premolars, I view 
the two jaw-specimens above indicated as pertaining to Hyrachyus. 

Professor Marsh has described several specimens, from Grizzly Buttes, 
under the name of hopModon nanus, which I suspect to belong to the same 
animal as the lower-jaw fragments above indicated. Pie observes that the 
most characteristic of the specimens is a right upper jaw containing a series 
of four premolars and three molars. If, then, this really, belongs to the same 
animal, it would give with the lower-jaw specimens, as the formula of the 
molar series, seven teeth above and six below, as in the tapir. The upper 
]u-cmolars, however, jiresent a greater amount of difference from the molars 
than in the latter, the difference being mainly diic to a less degree of develop- 
ment of the premolars and in the connation of the inner lobes of their 
crowns. 

The molar teeth and the portion of the jaw containing them are almost repe- 
titions of form of the corresponding parts in Hyrachyus agrarius. The men- 
tal foramen is situated below the first premolar. Hyrachyus nanus was 
about half the size of //. agrarius. 

Measurements from two lower-jaw specimens areas follows: 

Space occupied by the complete series of molar teeth 2 .inches. 

Space occupied by the premolars 93 lines. 

Space occupied by the molars 14 lines. 

Depth of jaw below last premolar 10 lines. 



Diameter of llrst premolar 

Diameter of second premolar. 

Diameter of last premolar 

Diameter of fir.st molar 

Diameter of second molar . . . . 
Diameter of last molar. 



Fore and 


nil. 


Transverse. 


Lines. 




Lines. 


2i 










3i 




-h 


n 




"4 


4 




3 


4.1 




H 


H 




H 



Fig. 11, Plate XXVI, represents the greater part of the right ramus of 
the lower jaw of Hyrachyus nanus, which I found, together with a fra'^mcnt 



G9 

oC tlic opposite side and several other bones ot the skeleton, near the Lodge- 
Pole Trail, crossing Dr}' Creek Valley. The specimen was found in part ex- 
posed and partially imbedded in the indurated clay of a bntte, in company 
with quite a profusion of well-preserved shells of Helix tvi/omingensis. 

The jaw resembles in its form that of Hyrachyus agrarius, and also that 
of the recent tapir. It contained a series of six molars, of which it retains 
the back four.. The molars are separated by a wide hiatus from a continuous 
arch of alveoli, for the accommodation of the incisors and canines, which corres- 
pond in number with those of the tapir. 

The depth of the jaw is rather less than in the fragments prciviously 
described, while the dimensions of the molar series is nearly the same. The 
measurements of the specimen are as Ibllows : 

Lines. 

Length of space from incisive alveoli to back of last molar 42 

Leugtli of space occupied by f lie molar scries 24 

Length of space occupied, by the true molars 14i 

Autero posterior diameter of last molar 41 

Length of symphysis ... IG 

Length of hiatus in advance of molars 13 

Depth of jaw below uiolars 9J 

An upper-jaw fragment, recently sent to me by Dr. Carter, I suppose to 
pertain to Hyrachyus iianiis. It contains the fangs of the anterior three 
premolars, and the entire last one, which is represented in Figs. 21, 22, Plate 
XXVII, magnified two diameters. This premolar resembles the corresponding 
tooth o{ H. agrarius, but the ridge in the latter, w^hich represents the postero- 
internal lobe in the true molars, is reduced to the smallest rudiment. 

The space occupied by the four premolars measures 11^ lines. The 
' breadth of the last premolar is 3.2 lines ; the width transversely is 4 lines. 

LOPHIOTHERIUM. 

LOPHIOTHERIUM SYLVATICUM. 

The genus Lophiotherium was proposed by Gervais, from some fragments 
of several lower jaws with molar teeth, which were found in association with 
remains of true Palseotheria, in a formation of France which he regards as 
belonging to the upper Eocene Tertiary. The genus is viewed as a tapiroid 
pachyderm closely allied to Lophiodon, though the molar teeth appear very 
unlike those of the latter. 

Daring Professor Ilayden's exploration of 1870, a specimen was found on 



70 

Henry's Forkof Green River, which appears to pertain to a species oi'Lophiothe- 
rium. The specimen, represented in Fig. 33, Plate VI, consists of a lower- 
jaw fragment containing the last premolar and the first and last true molars 
— the crown of the intervening true molar having been lost. The teeth 
appear closely to resemble in form and constitution those of LophiotherUan 
cei-vulum, as represented in Plate II of Gervais's Zoologie et PaUontologie 
franQaises. The only apparent difference, which, nevertheless, is an important 
generic one, if it really exists, is the division of the summit of the antero- 
internal lobe of the crown of the teeth into two points in the American fossil. 

The anterior teeth, Fig. 34, of the latter have oblong quadrate crowns, 
slightly narrower at the fore part and otherwise alike in form. They are 
quadrilobate, tlie lol^es being tri-laterally pyramidal and connate at base. 

The last molar. Fig. 35, is prolonged behind in the manner so common in allied 
animals of the same order. This prolongation is mainly due to the addition of 
a fifth lobe to the crown, which is narrowed posteriorly in the reverse direc- 
tion to the teeth in advance. 

A strong basal ridge incloses the crowns of the teeth, excepting internally. 
In the last molar it is less well developed and does not exist posteriorly. The 
constituent lobes of the crowns are nearly of uniform size. The antero-in- 
ternal lobe, as before intimated, has its summit divided into two points. The 
division extends so short a distance that it w<nild be early obliterated from 
the wearing of the teeth in the trituration of the food. It is hardly percepti- 
ble, even in the unworn condition in the last molar, and in the specimen is 
most distinct in the first true molar. As a character, it may l)e inferred to be 
most obvious in the anterior two true molars, and less so in the premolars of 
like_form and in the last true molar. 

The postero-internal lobe of the crowns has a simple pointed summit. The 
inner lobes have the crescentoid summit declining from a central point in- 
wardly, so common in the corresponding teeth of allied animals. The fore 
arm of the summit of the antero-ext'ernal lobe is a thick ridge curving to the 
base of the antero-internal lobe in front. The back arm is a short ridge 
directed inwardly to the anterior division of the summit of the antero-internal 
lobe. The fore arm of the summit of the postero-exteinal lobe reaches the 
middle of the antero-internal lobe. The back arm joins the posterior basal 
ridge, proiUicing an elevated point at its middle. From the inner side of the 



71 

same lul)e a tliinl but less conspicuous ridge extends directly to the loI)e 
within. 

In the last molar the fifth lobe has a crescentoid summit declining from a 
median point. The outer arm of the summit joins the contiguous arm of tlie 
lobe in advance, and the inner arm joins the base of the postero-internal lobe. 

The minutely detailed description of these teeth, and the same may be 
said of those of other fossils, is essential to the distinction of generic characters. 

From the back molars of Lophiodon, those of Lophiotherium especially 
differ in the distinction of four instead of two lobes to the crown : though the 
two lobes in the teeth of Lophiodon and Tapirus represent the four of Lo- 
phiotherium in a connate condition. 

The jaw-fragment of the fossil referred to Lophiotherium srjlvatician pre- 
sents nothing peculiar. The outer vertical surface is slightly convex, and the 
base fore and aft is also moderately convex. 

The measurements of the fossil are as follows . 

Liucs. 

Depth of lower jaw below middle of last premolar 5;| 

Depth of lower jaw below middle of last true molar '- Gi 

Anteroposterior diameter of last premolar - 3.^ 

Autero-posterior diameter of first true molar 3^ 

Autero-posterior diameter of second true molar 3iJ 

Autero-posterior diameter of last true molar 5^ 

Transverse diameter of last premolar -'i 

Transverse diameter of trne molars 2J 

Should the duplication of the summit of the antero-internal lobe of the 

crown of tiie lower back molars not be a character present in the Lopliio- 

therimn cervulum of France, it would probably be a concomitant of other 

characters in the upper teeth, now unknown to us, which would distinguish 

the American animal as generically distinct from Lophiotherium. 

. In the American Journal of Science for 1871. Professor Marsh notices 

some remains, from Grizzly Buttes, which be attributes to a species about 

two-lhirds the size of the fcjrmer, and names it Lojjhiotherium BuUardi. 

TROGOSUS. 

Trogosus castoridens. 

One of the most curious of the extinct mammals of the Bridger Tertiary 
fauna is an odd-toed pachyderm about the size of the larger living peccary, 
which, with the usual complement of molar teeth, was apparently devoid of 
canines, and was provided with a large pair of incisors like those ol' rodents. 



72 

The singular character of the aiiunal was first recognized in a fossil specimen; 
consisting of a mutilated lower jaw, discovered by Dr. Carter in the vicinity 
of Fort Bridger, and sent to the writer in the spring of 1871. The specimen, 
represented in Figs. 1 to 3, Plate V, besides the two large incisors, contains the 
remains of most of the molar teeth, but none in an entire condition. The 
best preserved is the second molar of the left side, and this is so much worn 
as to have the distinctive features of its triturating surfiice, as seen in Fig. 2, 
completely obliterated. 

The specimen was originally described in the proceedings of the Academy 
of Natural Sciences in May, lb71, and from its peculiarities the animal to 
which it belonged was named Trogosus castoridens, or the beaver-toothed 
gnawing hog. Professor Marsh had previously described an isolated tooth, 
of the same animal, from Grizzly Buttes, which he referred to a species of 
Palseosyops with the name of P. minor. From the description, I supposed it 
not to difler from P. j)aludosus. An examination of the specimen has satis- 
fied me that it belonged to the*same animal as the jaw referred to Trogosus. 

The isolated tooth belonged to a younger animal, and is not so worn as to 
have the characteristic arrangement of its masticating surface destroyed. On 
seeing it I was struck with its resemblance to anotlier isolated molar tooth 
wliicli I had formerly described under the name Anchipjjodus riparius. This 
tooth was discovered by Dr. Knieskern in a Tertiary formation, supposed to 
be of Eocene age, in Monmouth County, New Jersey. It was given to Mr. 
T. Conrad, by whom it was ]5resented to the Academy of Natural Sciences 
of Philadelphia. The same formation has yielded the remains of a peccary, 
an Elotherium, and a rhinoceros. 

A comparison of the tooth of the New Jersey Anchippodus with the cor- 
responding one in the jaw-specimen and with liie isolated molar, would appear 
to indicate that the Wyoming fossils belong to the same genus, and indeed 
the teeth are sufficiently alike in form and size to pertaiji to the same species. 
Should further discovery prove this to be the case, it would, perhaps, indi- 
cate the contemporaneous character of the Bridger Tertiary foi-mation of 
■Wyoming and that of Monmouth County, New Jersey. The New Jersey 
fossil, in its general appearance of color and condition, so closely resembles 
the Wyoming fossils that it would readily pass for one of them. 

It is by no means positive that Trogosus and. Anchippodus are the same, 



73 



fur we have examples enough ul' different genera having the lower molars 
alike, while the upper ones and the premolars are unlike. 

The jaw of Trogosus retains evidences of the existence of six molar teeth, 
and there may have been another small premolar, but this cannot be ascer- 
tained from the mutilated condition of the specimen. The first of the series 
of six molar teeth approached so close upon the lai-ge incisor as to leave but 
a small interval for the introduction of other teeth. 

The best preserved tooth of the molar sei'ies, the second molar, presents a 
bilobed crown, in which the anterior lobe is the longer or least worn. The 
triturating surface, represented in Fig. 2, Plate V, exhibits a wide tract of 
exposed dentine with a yoke-like outline of enamel. Its fore and aft meas- 
urement is 9J lines. The thickness of the anterior lobe at base is 8 lines. 

In the less worn specimen of the corresponding tooth described by Profes- 
sor Marsh, he gives the antero-posterior diameter as 10 lines; the transverse 
diameter at the summit of the lobes of the crown as 5 and 5J lines wide. 

The constitution of the lower molars of Anchippodus is apparently the 
same as in Trogosus, as observed in the New Jersey tooth represented in 
Figs. 45, 46, Plate XXX, of " The Extinct Mammalian Fauna of Dakota," &c. 
Fi-om this it will be seen the crown is composed very nearly on the same 
plan as that of the corresponding teeth in Anchitherium, Palseotherium, &c. 
It is composed of a fore and aft pair of lobes with crescentoid summits, 
convex externally and with a recess internally. The size of the tooth is the 
same as that retained in the jaw-specimen above described. The fangs of 
the last molar in the lower jaw indicate a trilobed ci'own,*as in Anchitherium, 
Pateothferium, &c. The premolars, so far as can be ascertained by their 
remains in the jaw, are inserted by two fangs. Canines most probably do 
not exist in Trogosus, their absence being fully compensated by the large 
incisors. 

The incisor teeth on both sides together are iour in number; but while 
the lateral ones are developed to the proportions of those of rodents, the 
intermediate pair were quite small. The latter are lost from the specimen, 
leaving the alveoli occupied by matrix. The space they occupied was about 
the fourth of an incli from side to side. 

The large lateral incisors are wonderi'ully like the incisors of rodents, not 
only in form, position, and structure, but they were also alike in their perpet- 
IOg 




74 

uiil mode of growth. Tliey do not extend so far hack within the jaw as in 
most rodents, and in this respect are more like those in the rabbits, or, as in 
tlieir nearer relatives, the peccary and hog. They extend beneath the pre- 
molars, but the bottom of the alveolus does not reach the position of the first 
molar. 

The incisors are convex in front, and not flat, as usual in rodents. The 
anterior convexity is invested with thick enamel longitudinally striated, the 
striiB being wrinkled. Externally the edge of the enamel appears proportion- 
ately more prominent than in rodents ; that is to say, it projects more above 
the level of the contiguous exposed dentine. In transverse section the incisors 
are ovoid, with the narrow extremity behind. The fore and aft diameter of 
the section is 10 lines ; the transverse diameter at the edges of the enamel 
layer is 6 J lines. The anterior convexity covered with enamel is 4 lines ; 
the posterior convexity is J an inch. 

The cutting edges of the incisors are broken, but the extremities of the 
teeth are sufficiently well preserved to exhibit the manner of wearing. They 
were not only worn in a sloping manner backward, as in rodents, but also 
externally, so that it appears the upper incisors were more divergent than the 
lower ones, and held a position related to them more like the condition 
observed in the peccarj'. 

The rami of the jaw, as usual in pachyderms, are completely co-ossified. 
The. symphysis is remarkably strong and deeji, and in the median line is 
nearly 3 inches in length. The rami just back of the symphysis are nearly 
an inch thick. The chin forms a long, broad slope, defined at the sides by 
the pronnnences of the large incisor alveoli, curving from the base of the 
jaw ])arallel with each other upward and forward. The chin resembles that 
of the peccary or rhinoceros, but is more convergent, as in the beaver. 
Approaching the exit of the large incisors from their alveoli the intermediate 
space is deeply grooved, as represented in Fig. 3. 

The body of the ramus is short, deep, and thick. Its outer surfixce is ver- 
tically convex. The base is thick and convex fore and aft as well as trans- 
versely. 

The masseteric fossa is deep, and extends downward to about the middle 
line of the bodj^ of the ramus. Two mental foramina on one side, and tliree 
on the other, occupy a position in advance of that of the last premolar. 



75 
Measurements taken from the lower-jaw specimen are as lollows : 

Inches. Lines. 

Distauce from iucisive alveoli to back of last molar i 10 

Space occnpied by the molar teeth, estimated . .' 4 

Space occupied by the true molars 2 7 

Fore and aft diameter of last molar 1 I 

Depth of jaw at second molar 1 G 

Thickness of jaw below second molar 10 

Estimated length of lateral incisors " 3 3 

Depth of symphysis following its slope li 10 

Trogosus vetulus. 

An apparent smaller species of Trogosus is indicated b}^ the fragment of an 
incisor tooth, represented in Fig. 43, Plate VI. The specimen was discov- 
ered by Dr. Carter in the vicinity of Fort Bridger, and sent to the writer last 
summer. It consists of the exserted portion of the tooth, and agrees in form 
and proportions with the corresponding portion of the incisors in the jaw- 
specimen above described. The enamel is smoother, but invests the tooth to 
the same relative extent. The antero-posterior diameter of the tooth lias 
been about 8 lines ; the transverse diameter 4 lines. 

HYOPSODUS. 

Hyopsodus paulus. 

One of the smallest of pachyderms, referred to a genus and species above 
named, is established on many specimens, chiefly consisting of portions of 
lower jaws with teeth, (Figs. 1 to 9. Plate VI.) It was originally indicated, 
fi'om a lower-jaw fragment with teeth (Figs. 1, 2) of an old animal, discov- 
ered by Professor Playden, in 1870, in the vicinity of Fort Bridger, Wyo- 
ming. Since then the writer has received a number of more characteristic 
specimens, obtained l)y Dr. J. Van A. Carter and Dr. Joseph K. Corson, at 
Grizzly Buttes, Henry's Fork of Green River, Lodge-Pole Trail, and other 
localities in the neighborhood of Fort Bridger, Wyoming. 

The animal was rather less in size than the Ajjhelotherium Duvernoyi of 
Gervais, the remains of which were found in the gypsum quarries of Paris, 
France. It also appears to have been allied to this, as indicated by the num- 
ber, relation, and constitution of the teeth. Both Aphelotherium and Hyop- 
sodus possessed unbroken arches of teeth to the jaws, as in the Anoplothe- 
rium, whose remains are found in association with those. of the first-named 



genus. 



76 

The iminber of teetli in Hyopsodiis appears to be three incisors, a canine, 
and seven molars to the series on each side of both jaws. 

Neither incisors nor canines are preserved in any of the specimens we 
have the opportunity of examining. Two lower-jaw specimens retaining 
portions of the incisive, canine, and premolar alveoli, and the true molars, 
apparently prove the numl)er of teeth to be as above indicated. 

The canine tooth of Hyopsodus is comparatively of small size, though 
larger thmi the incisors or the first premolar. It appears to have about the 
same size in relation with the other teeth as in Aphelotherium anjd Anoplo- 
therium. 

The premolars successively increase in size from the first to the fourth. 
The first possesses a single fang ; the others two fixngs. The anterior two 
premolars are lost from all the specimens under examination. 

The inferior true molars (Figs. 1 to 9, Plate VI) of Hyopsodus have 
oblong quadrately oval crowns, with the fore and aft diameter exceeding the 
transverse, which is about equal to the depth. They are inserted in the 
usual manner in pachyderms by a pair of fangs, the posterior of which in 
the last tooth is widened backwardly, as is commonly the case in congeneric 
animals. 

The crowns are composed of four principal lobes, connate at base ; but 
the crown of the last tooth has an additional or fifth lobe at its back part as 
well developed as some of the lobes in advance. A rudiment of this fifth 
lobe is recognized in the other true molars as a small tubercle, occupying a 
corresponding position. 

The four principal lobes of the crown of the true molars are arranged in 
pairs not quite transverse, but slightly oblique, so as to appear somewhat 
alternating. The fifth lobe of the last molar is opposite the interval of the 
pair of lobes in advance. 

Of the four lobes, the outer are demi-conoidal, and the posterior one is 
slightly the larger. The inner lobes are simply conical, and the anterior is 
the larger. The outer lobes in the unworn condition have acute crescentoid 
summits, or form V-like ridges, with the arms declining from the pointed 
angle. The inner lobes in the same condition have pointed summits. 

The contiguous horns of the crescentoid summits of the outer lobes join 
the antero-internal lobe. Tiie anterior horn of the crescentoid summit of the 
antero-external lobe curves inwardly to the base of the antero-internal lobe. 



77 

Tlic jiosterior lioni of tlic crescentoid summit of tlic postero-extenial lobe 
ends in the tubercle at the back of the crown, and in tiie last molar, in the 
homologous fifth lobe. The latter is joined by an acute ridge, descending to 
the base of the postero-internal lobe. 

A thin basal ridge exists at the fore and back parts of the crown of the 
first and second molars, and the fore part in the last molar. An element 
also exists at the interval, externally, of the outer principal lobes, and in some 
specimens is more or less produced around the bottom of the antero-external 
lobe. 

As the crowns of the true molars are worn away, circular islets of dentine 
appear at the summits of the inner lobes, and crescentic islets at the summits 
of the outer' lobes. In the progress of attrition the dentinal surfaces expand, 
and the horns of the crescentic islets become united with the circular islets. 
In an advanced stage of wear the triturating surface of the molars presents two 
elliptical surfaces crossing the crown, with a slight obliquity, and united by a 
median isthmus, the whole bordered by a band of enamel. Such a condition 
is seen in the specimen represented in Figs 1, 2, Plate VI, which is that 
upon which the genus was originally proposed. By comparing this with the 
others in different stages of wear, represented in Figs. 3 to 9, of the same 
plate, its correspondence with these, whicli preserve more characteristic 
generic marks, can be readily recognized. 

The last lower premolar of Hyopsodus (Figs. 5, 8, Plate VI) is smaller 
than the true molars, and like them is inserted by a pair of fangs. Its crown 
is proportionately of greater depth than in the true molars, and, as in these, is 
widest fore and aft. The outer fore part of the crown is composed of a demi- 
conoidal lobe, which is the principal one, and it corresponds with the antero- 
external lobe of the true molars. It has the same form as the latter lobe, but is 
better developed. The anterior horn of its crescentoid summit forms a curved 
ridge, defining the fore part of the triturating surface of the crown. The poste- 
rior horn of the crescentoid summit terminates in a small conical lobe occupying 
the middle of the crown internally. The back of the crown is tbrmcd By a 
broad heel, skirted by a basal ridge externally, and divided by another ridge, 
which descends from the summit of the principal lobe of the crown, and bor- 
ders the heel posteriorly and internally. A thin basal ridge occupies the fore 
part of tlie crown. In the wearing of the crown of the last premolar, the 
exposed dentine assumes the Ibrni of the Greek letter t, lying on its right 
side. 



78 

The penultimate lower premolar (Fig. 8) is a reduced form of the one 
behind, with the internal median conical lobe obsolete. 

The lower jaw has its two rami co-ossified at the symphysis. It is thick 
and rounded at the base, which is convex fore and aft beneath the molar 
series. The chin is rounded transversely. The masseteric fossa is well 
marked and defined anteriorly by a prominent ridge descending from the 
front border of the coronoid process to the lower third of the side of the jaw. 

The ramus of the jaw would appear to have increased in depth and 
assumed a more robust condition in the advance of age, for in those specimens 
in -which the teeth are least abraded, the jaw is shallowest, and in that in which 
they are most worn it is deepest. Specimens exhibiting the teeth in an 
intermediate state of wear have the jaw of intermediate depth and strengtli 
to the others. 

All the specimens represented in Figs 1, 3, 4, 6, and 7 I attribute to the 
same species, notwithstanding the difference in the proportion of length lo 
depth in the different ones. 

Two or three mental foramina occupy a slightly variable position beneath 
the premolars. 

During the summer of 1871, Dr. Carter discovered, at Grizzly Buttes and 
Lodge-Pole Trail, several specimens, consisting of fragments of upper jaws 
with well-preserved teeth, which are of a size and form that would adapt 
them to the lower-jaw specimens of Hyopsodus. 'I'he specimens from 
Grizzly Buttes were accompanied by one of the lower-jaw specimens upon 
wliich the latter was founded, and this looks sufficiently like several of them 
in general appearance to have belonged to the same individual. 

One of the specimens represented in Fig. 18, Plate VI, contains a series 
of three premolars and the succeeding molars. In advance of the series there 
remains a portion of an alveolus which apparently belonged to another pre- 
molar. If such is the case, the number of premolars would be the same as_ 
in the lower jaw of Hyopsodus. 

The teeth (Figs. 18 to 22) increase in size from the first to the sixth, the 
seventh being again reduced to the size of the fifth The second premolar 
is inserted by a pair of fangs of which the posterior is wider than the other. 
The succeeding premolars and molars are inserted with three fangs, of which 
the inner one of the molars is a connate pair. 

Tiie crowns of the molars (Figs. I'J to 21) are quadrate, wider transversely, 



79 

and abt)iif halt (he depth ot" the breadth. They arc composed each of six 
lolies expanding and continuous at base. The outer and inner pair of lobes 
are nearly equal ; the intermediate pair is smaller. 

The outer lobes of the molars are conical, and united where contiguous, 
but they do not form an external buttress by their union, the intei'vening 
surface externally being concave. In the last molar the posterior of the outer 
lobes is proportionately less well developed than in the others. 

The inner lobes of the crown are likewise conical, and united where con- 
tiguous. The posterior of tiiese lobes is the smaller, and in the last molar is 
entirely suppressed, or appears only as a slight elevation of the basal ridge 
occupying the back of the crown. The summit of the antero-internal lobe 
is prolonged obliquely to join the antero-median lobe. The summit of the 
postero-internal lobe is prolonged outwardly back of the postero-external 
lobe, so as to appear as a basal ridge to this part of the crown. 

The median lobes hold a slightly more advanced position than the includ- 
ing lobes. The back one is isolated or free to its base ; the front one, by 
prolongation, is associated with the antero-internal lobe and the fore part of 
the base of the antero-external lobe. 

A strong basal ridge occupies the fore part of the crown, and also, less well 
developed, festoons the outer part. 

In the wearing of the upper molars (Figs. 19 to 21) islets of dentine first 
appeared at the summits of the six lobes of the crown. Those of the two 
outer lobes soon became continuous ; followed by those of the antero-median 
and anteror internal lobes With the widening of these two tracts, the islet 
of the postero-internal lobe next became continuous with that in advance. 
At this stage there would appear three dentinal tracts: one lor the outer pair 
of lobes, a second for the internal and antero-median lobes, and a third as a 
circular islet on the postero-median lobe. 

The posterior two premolars (Figs. 19, 21) have bilobed crowns, remind- 
ing one of the premolars of ruminants. The sudden reduction from the six 
lobes of the crown of the molars to the single pair of the crown of the pre- 
molars is a remarkable anatomical character. The lobes are pyramidal, and 
so far spread apart as to give the crown a greater width transversely. The 
summit of the inner lobe forms a crescentoid ridge, embracing the bottom of 
the outer lobe. A strong basal ridge bounds the fore and back part of the 
crown, and festoons it externally. 



80 



In the Uiird premular the inner lobe is less well developed at its fore part 
than in the fotirth. 

The crown of the second premolar (Figs. 19, 22) is formed of a single 
conical lobe, corresponding with the external lobe of the succeeding tooth. 
Postero-internally, it presents a feeble rudiment of an inner lobe. The 
crowns of the premolars were worn away mostly in a slanting manner poste- 
riorly. The exposed dentine in the two lobed crowns became continuous at 
». the back of the crown. 

The molars above described resemble, in construction and in the relative 
position of the six lobes of the crown, those of Hyracotherium and Pliolophus, 
two extinct genera of pachyderms, described by Professor Owen from remains 
found in the London clay, an Eocene formation of the estuary of the Thames. 
In both the genera named the last molar is ])roportionately better developed ; 
and in all the molars the postero-internal lobe and the basal ridge are likewise 
proportionately better developed. The upper pi-emolars are quite different.. 
In Hyracotherium the back t\yo premolars have five lobed crowns, and in 
Pliolophus the last premolar has a similar constitution. 

Too small a portion of the jaw (Fig. 18) containing the teeth above 
described has been preserved to ascertain anything of importance as to the 
shape of the face. The infra-orbital foramen is situated immediately above 
the interval of the back two premolars. 

Measurements from some of the upper-jaw specimens and teeth above 
described are as follows : 



Specimens in Plato VI. 



Figs. 18,19. 



i Lines. 

Si)ace occupied by series of six molar teetb 9 

Space occupied liy true molars 5 J 

Space occupied by tbree premolars 3^ 

Breadtb of .second premolar 1 

Widtb of second premolar 1 

lireadtli of tbird premolar ' IJ 

Width of tbird premolar li 

Breadtb of fourth premolar i 1^ 

Width of fourth premolar 2 

Breadth of first molar '' 1^ 

Width of first molar ' 2^ 

Breadtb of second molar i 2 

Widtb of secoud molar 2J 

Breadth of last molar 1^ 

Width of last molar 2 



Fig. 20. 



21 



U 
2i 



Lows. 


L 


incs. 


5 


^ 








• 

















^ 

21 



12 

2i 



81 



HyOPSODUS MINU6CULU.S. 

A smaller species of Hyopsodus than the one described in tlic jireceding 
pages appears to be indicated by a specimen discovered by Dr. Carter in the 
buttes of Dry Creek. The specimen consists of an upper-jaw fragment con- 
taining the true molars and part of the last premolar, which are represented 
in Fig. 5, Plate XXVII. The teeth differ in no essential character and only 
in size. Their com partitive measurement with those of H. paulus are as 
follows : 



Hyopsodus 
mimisculiis. 



Hyopsodus 
paulus. 



Leugtli of space occupied by the last premolar ami molars. . 

Length of space occupied by the molars 

Breadth of last premolar 

Width of last preaiolar 

Breadth of tirst molar , 

Width of first molar 

Breadth of secoud molar , 

Width of second molar 

Breadth of third molar - 

Width of third molar 



Lines. 
5,4 
4.4 
1.05 



8 

6 



6 

1 

25 

7 



Lines. 

6.45 

5.2 

1.4 

2 2 

1.8 

2.4 

2.0 

2.8 

1.6 

2.35 



MICROSUS. 

MiCROSUS CUSPIDATUS. 

The genus Microsus is obscurely determined and is uncertain in its distinc- 
tion from the previous genus. It was originally inferred from the lower-jaw 
fragment with the back two molars, represented in Fig. 10, Plate VI, at the 
same time that Hyopsodus paulus was characterized from the only specimen 
then in our possession, represented in Fig. 1 of the same plate. The well- 
marked difference in the form and proportion of the corresponding portion of 
the jaw led me to view it as pertaining to a diffei'ent genus fi'ora Hyopsodus. 
Subsequently I have had the opportunity of examining many and more char- 
acteristic specimens referable to the latter, but none which with any certainty 
could be ascribed to Microsus. 

The jaw-specimen referred to the latter was obtained by Professor Hay- 
den on Black's Fork of Green River. The jaw would appear to be narrower 
and weaker than hi Hyopsodus. The fragment as seen in Fig. 10, in com- 

11 G 



82 

parisoii with corresponding portions ofllic latter, as seen in Figs. 1,3,4, 7, is 
proportionately of less depth, and at the base beneath the molars curves 
much more upwardly in a back-ward direction. 

The teeth, represented in Figs. 10 and 11, are unworn, and they liave the 
same size and constitution as those of Hyopsodus. In the specimen the con- 
stituent lobes of the crown appear more prominent and their intervals more 
deeply angular than in those of Hyopsodus, but this difference is probably 
due to difference in age. In all the specimens ascribed to Hyopsodus the 
teeth are more or less worn, and only in that attributed to Microsus are they 
unworn. Observing, also, that the proportionate depth of the lower jaw in 
the different specimens of Hyopsodus holds some relationship with the age 
of the animal, as indicated by the extent of wearing of the teeth, I have sup- 
posed that the variations observed in the jaw-fragment of Microsus might be 
due to the same cause, and that it therefore really pertains to Hyopsodm jjau- 
lus. Thus by comparison of Fig. 10, representing Microsus, with that of 
Fig. 6, representing a specimen of Hyopsodus, in which the teeth are least 
worn, the resemblance is observed to be greater than with the other and 
older specimens of Hyopsodus. 

Comparative measurements of the specimen referred to Microsus with 
specimens of Hyopsodus represented in Figs. 1, 3, and 6 are as follows: 



Depth of lower jatv at fore part of last molar 

Space occupied by last two molars 

Auteroi)osterior diameter of last molar 

Antei'o-posterior diameter of second molar. . 



Microsus. 



Lines. 



"5" 



Hyopsodus. 



Via. 10. Fig.- 1 



Lines. 

H 

O 



Fig. 3. Fig. 6. 



Lines. 

H 

5 

2 



Lines. 



MICROSYOPS. 

An extinct genus of small mammals, to which the above name was given, 
was originally founded, on several lower-jaw fragments containing molar teeth. 
Though classed among the pachyderms, it is not positive that such is the true 
position of the genus. The more complete of the specimens upon which it 
was characterized indicates a series of six molar teeth following closely after 
a well-developed canine. The number of incisors is unknown. 



83 

In the genus Limnothoriuni, as established by Professor Marsh, from the 
typical species Z. ti/nmnus, the dental formula consists of two incisors, a 
canine and seven molars. 

Mycrosyops gracilis. 

The more characteristic specimen upon which this species was named con- 
sists of a portion of the left ramus of the lower jaw, represented in Fig. 14, 
Plate VI, of the natural size. The specimen was discovered by Dr. Carter 
on Grizzly Butte. Besides the fang of the canine and those of the premolars, 
it contains the true molars entire. These are moderately worn at the sum- 
mits of the constituent lobes of their crowns, and their triturating surfaces 
are represented in Fig, 15 of the same plate, magnified four diameters. The 
jaw-fragraent retains part of the rough sutural surface of the symphysis, show- 
ing that its union was ligamentous with the other ramus. The basal portion 
beneath the molars is broken away. Below the premolars it is of moderate 
depth and thickness, and soon curves upward with the fang of the canine. The 
mental foramen is situated below the second premolar. The fang of the 
canine indicates a proportionately larger tooth than in Hyopsodus. It is lat- 
erally compressed and curves ujjward, forward, and t)utward. The transverse 
section is oval with the long diameter directed obliquely forward and out- 
ward, and measuring 1.8 line, while the short diameter is 1 line. 

The premolars successively increase in size. The first is separated by a 
slight hiatus from the canine, and was inserted by a single fang. The others 
have two fangs. 

The molars have oblong quadrately-oval crowns of nearly uniform size. 
They are inserted with two fangs, with the back one of the last molar widened, 
as usual in most ungulates. 

The crown of the molars is composed of two divisions, in addition to 
which the last one has a large posterior tubercle. The anterior division of the 
crown is smaller than the posterior, and appears of the same form in a more 
contracted condition. Each division consists of an external crescentoid coni- 
cal lobe and an internal rudimental conical lobe or tubercle, whicli is placed 
opposite the back part of the former lobe. 

The front arm of the anterior crescentoid. lobe ends in a thickening in ad- 
vance of the antero-internal lobe. Tlie corresponding arm of the better de- 
veloped posterior crescentoid lobe terminates at the base of the lobe in front 
of it. The back arm of the same lobe forms a slight thickening contiguous 



84 

to thr. postero-intenjal lobe. In the last molar this thickening appears to be 
developed into the large tubercle back of the second division of the crown. 
Feeble traces of a basal ridge occupy (he interval of the outer lobes and the 
• back of the crown. 

Measurements of the lower-jaw specimen oi Microsyojjs gracilis. are as fol- 
lows : 

Lines. 

Depth of lon-er jaw below last molar 4 

Thickuess of lower jaw below last premolar 2J 

Distance from canine alveolus to back of last molar 10 

Space occupied by the entire molar series , 9| 

Space occupied by tbe premolars 4 

Space occupied by the molars » 5| 

Breadth of first molar 1^ 

Breadth of second molar ., 2 

Breadth of third molar 2 

The specific name of 31. gracilis was originally given under the impression 
that the remains referred by Professor Marsh to Hyopsodus gracilis pertained 
to the same animal. A specimen exhibited to the writer by Professor Marsh 
would indicate that M. gracilis is the same as the animal named by him 
Limnothcrium elegans. As Microsyops is generically distinct from Limno- 
therium, as characterized from the typical species L. tyrannus^ the specific 
name of the former would be Microsyops elegans. 

Another specimen, originally referred to Microsyops gracilis, is represented 
in Fig. 16, Plate VI, and was found by Dr. Carter near Lodge-Pole Trail, 
about tea miles from Fort Bridger. It consists of a portion of the left ramus 
of the lower jaw, containing the j^enultimate molar and part of the last one. 

The only remaining entire molar, a view of the triturating surface of 
which is given in Fig. 17, closely resembles the corresponding tooth in the 
specimen first described, except that it is a little larger. (The artist has 
made it appear different by exaggerating the proportions of the tubercle be- 
tween the posterior lobes, and leaving it out altogether in the corresponding 
view of Fig. 15.) The remaining portion of the last molar also agrees with 
the corresponding portion in the first-described specimen. The lower jaw is 
comparatively deep, and is nearly straight along the base. The fore part 
with the symphysis is lost, but it would appear not to have been so shallow 
and thick as in the former specimen, which leads me to suspect that it 
perhaps belongs to a different animal. The mental ibramen holds the same 
relative position as in the other specimen. The ridge bordering the lore 



85 

jiaii (){' (lie coroiioid process terminates in a tul)ercle at the fore part ol Ihe 
moderately deep masseteric fossa. 

Another foramen, perhaps not constant to the species, is situated below 
tlie position of the fore part of the first molar. 

The measurements of the specimen are as follows: 

Lines. 

Depth of jaw below last molar -if 

Depth of jaw below last premolar 4^^ 

Space occupied bj' last i)remohir and molars 7^ 

Space occupied by the molars 

Breadth of penultimate molar 2J 

Breadth of last molar 2^ 

The only specimen of an upper tooth which may, with any probability, be 
supposed to belong to Microsyops, is contained in a small fragment of the 
jaw, found by Dr. Carter on Dry Creek. The tooth, apparently a first or 
second molar, is represented in Figs. 19, 20, Plate XXVII. The crown is 
not so square and is proportionately of less breadth fore and aft than in the 
corresponding tooth of Hyopsodus. It narrows inwardly more than in the 
latter, the reduction taking place posteriorly, where the crown is concave. 
The constitution of the tooth is nearly as in Hyopsodus, and the principal 
difference is found in the condition of the postero-internal lobe. In Hyopso- 
dus, this is a reduced form of the lobe in advance, being crescentoid. In the 
supposed tooth of Microsyops, the postero-internal lobe appears as a conical 
tubercle springing from the base postero-internally of the larger crescentoid 
lobe in front. In Hyopsodus, the postero-median lolje is a simple cone, but 
in the tooth in question it is pyramidal. 

The antero-posterior diameter of the crown external!}' is 1.6 lines ; inter- 
nally, 1.2 lines; the transverse diameter anteriorly is 2.2 lines. 

Undetermined. 

Fig. 12, Plate VI, represents a specimen found by Dr. Carter on Henry's 
Fork of Green River. It consists of a lower-jaw fragment with the last pre- 
molar and the fangs of the molars of a mature animal of undetermined 
character, but, from the form of the remaining tooth, evidently allied with 
Hyopsodus. The premolar. Fig. 13, is unlike the corresponding one of the 
latter genus, as seen by comparing it with Figs. 5 and 8, but resembles tlie 
true molars. Suspecting that it might be a last temporary molar, notwith- 
standing its slightly worn condition and its association with the full series of 



8G 

molars in functional ])ositiou behind, 1 examined the jaw beneath, Init fouiKl ' 
110 trace of a successor. 

The portion of jaw is of more uniform depth, and the base less convex 
than in Hyopsodus. It is also more impressed and concave below the position 
of the back molars. The space occupied l\y the molars is about equal to 
that in the smaller specimens of Hyopsodus. 

Perhaps the sjiecimen may pertain to Microsus, or prol^ably may l)elong to 
a genus difTerent from either of those just named. Its measurements are as 
follows : 

Lines. 

Space occupied by tlie last premolar aud molars 7f 

Space occupied by tbe molars ■ . . 5| 

Depth of jaw at fore part of last molar '3^ 

Depth of jaw at last premolar Sf 

Anteroposterior diameter of last molar 2i 

Anteroposterior diameter of last i^remolar If 

NOTHARCTUS. 

NOTHAKCTUS TENEBROSUS. 

A small extinct pachyderm, referred to a genus with the above name, judg- 
ing from the anatomical characters of the specimen upon which it was founded, 
was probably as carnivorous in habit as the raccoon and bear. The specimen 
to which I allude, represented in Fig. 36, Plate VI, consists of tbe right 
ramus of a lower jaw with most of tbe teeth. It was discovered during Pro- 
fessor Hayden's exploration of 1870, on Black's Fork of Green River. I at 
first viewed it as pertaining to a carnivorous animal, and thus referred it ; but 
tbe anatomical relations of the specimen with those of remains of other ani- 
mals which have been found in association with it have led me to view the 
jaw as having belonged to a pachyderm. The ramus of the ja^v contained a 
series of seven molar teeth, all of which are preserved except the first pre- 
molar'. A well-developed canine occupies a position immediately in advance 
of the molar series, and the incisors filled the interval between the canines of 
the two sides. Thus the teeth of the lower" jaw of Notliarctus form an un- 
broken arch. The incisors are lost from the specimen, and the condition of 
the alveoli is such that the number of them cannot be ascertained. 

The canine tooth of Notharctus in its relative position, form, and propor- 
tions resembles that of ordinary carnivores. It curves from the opening of 
the alveolus slightly backward witli an inclination outward. The crown is 



87 

considerably elevated from an increased jirolrusion (if the fang, sucli as is 
observable in carnivorons animals past maturity. Tlie fang is gibbous and 
feebly curved. 

The molar teeth, represented in Fig. 37, magnified two diameters, are con- 
siderably worn in the specimen, all of therrt exhil)iting exposed tracts of den- 
tine, due to the wear of mastication. 

The four premolars successively increase in size, and are inserted by a pair 
of fangs, except the first, in which they appear to have been connate. The 
crowns of the premolars from behind forward exhil)it a successive reduction 
to a simpler form from that of the molars. 

The crowns of the second and tliird premolars, and no doubt also that of 
the first one, which is lost from the specimen, have the conical form of the 
corresponding teeth in carnivores, though they appear less prominent, due to 
their worn condition. They are slightly thickei" behind than in front, and a 
basal ridge internally forms a slight offset or heel posteriorly, and a still feebler 
one in the third premolar anteriorly. 

The crown of the fourth premolar is intermediate in character with tliose 
in advance and those of the molars behind. Its fore part consists of a conical 
lol)e like the crown of tlie anterior premolars ; its back part is a broad heel 
corresponding with the back lobe of the molars. The summit of the princi- 
pal lobe is extended obliquely inward and backward and is continuous with 
the inner basal ridge of the crown. Externally, the latter is embraced by a 
basal ridge. 

The crown of the second premolar is worn away along its posterior slope ; 
tlie crown of the third to a greater degree in a corresponding position, and 
also to a less degree along its anterior slope. 

. The molars are nearly alike in form and constitution, and are inserted with 
two fangs. The crown of the molars bears a certain degree of resemblance 
in construction to those of the raccoon, and in a less degree to those of the 
opossum, but certainly enough resemblance to both to indicate a relation 
which is not merely accidental. 

In the unworn condition of the lower molars of Notharctus, the crown 
would appear to be composed of two divisions. The anterior division pre- 
sents three prominent points continuous in an acute crescentoid ridge. The 
principal point is central and external, the second is nearly as well developed 
and internal, and the third point, feebly developed, occupies the fore part of 



88 

the crown The posterior division presents two elevated points, conjoined in 
a crescentoid ridge. The anterior extremity of this ridge joins the front 
division of the crown. Its more elevated point is extemal and posterior, and 
its less developed one occupies the postcro-internal corner of the crown. A 
l)asal ridge incloses the crown, except internally. 

Each division of the crown of the molars incloses in the arms of its cres- 
centoid ridge a depression, which is largest in the posterior division. The 
crown of the last molar is more prolonged backward than the others, arising 
from the greater degree of development in this direction of its posterior 
division. 

In the worn condition of tlie molars, as seen in Fig. 37, the crescentoid 
ridges of the divisions of the crown have been so much abraded as to expose 
broad crescentoid tracts of dentine continuous on the two divisions of the 
crown. 

The rami of the lower jaw of Northarctus appear to be co-ossified at the 
symphysis, and the specimen under consideration was broken off just to the 
left of the latter. The chin is narrow and convex transversely, and it forms 
a nearly straight or slightly convex slope of about 45°. The body of the 
bone is nearly of uniform depth; the relation of depth to length being much 
greater than in the raccoon and more in proportion witli the measurements 
in the hog and peccary. The outer flice of the body is nearly vertical. I'he 
base is thick and slightly convex fore and aft. Near the middle, directed in- 
wardly, it exhibits a'strong impression tor muscular attachment. 

The angle of the jaw, the back border of the bone, and the coronoid pro- 
cess ai'e lost. The outer face of the ascending portion of the ramus is 
depressed into a masseteric fossa extending nearly or quite to the base, but 
shallow compared with that of ordinary carnivores. The. condyle is remark- 
ably slioi't, and resembles that of some of the monkeys more than that of ordinary 
pachyderms. It is transversely oval, with the l^readth less than twice the 
fore and aft diameter, which is directed obliquely from without inward and 
backward. The articular surface is transversely convex and inclines more 
outwardly than inward. 

The form of the condyle clearly indicates more varied movements in the 
jaw than exists in the carnivora, and would rather be favorable to the proper 
reduction of the food of an omnivorous animal. 

A mental foramen occupies a position about mi<lway between the third 



89 

premolar ami lliu base ol the jaw. Twu small loramiiia arc situak'd IjcIow 
the position of the first premolar. 

Ill the American Journal of Science for 1871, Professor Marsh has 
described the lower jaw, with teeth, of a small pachyderm, under the name of 
Limnotherium tyrannus, which would appear at least to belong to the same 
genus as the former. The specimen was found near Dry Creek, Wyoming. 
According to the description and measurements, the jaw nearly accords with 
that of Notharctus tenebrosus. The teeth in an interrupted series consist of 
two incisors, a canine, four premolars, and three molars. If we suppose 
Notharctus to have two incisors, the numljer, character, and relative position 
of the teeth agree in both. In Limnotherium the first and second premolars 
are observed to have a single fang. This character alone would be insufficient 
to distinguish a genus, and, perhaps, would hardly be regarded as a specific 
character. The description of the molars of Limnotherium would apply to 
those of Notharctus. 

The measurements of the lower-jaw specimen o? Notharctus tenebrosus are 
as follows : 

Liucs. 

Leugtli of jaw from condyle to incisive alveoli 30 

Depth of jaw below last molar 5^ 

Depth of jaw below last premolar C 

Length of symphysis '^ 

Breadth of condyle j 

Anteroposterior diameter of condyle 2 

Length of dental series - 19^ 

Length of space occupied by the molar series Iti 

Length of space occupied by the true molars S^ 

Diameter of canine at base of crown 1| 

Fore and aft diameter of second premolar li 

Transverse diameter of second premolar f 

Fore and aft diameter of third premolar If 

Transverse diameter of third premolar li 

Fore and aft diameter of fourth premolar 2 

Transverse diameter of fourth i)remolar l-J 

Fore and aft diameter of first molar 2f 

Transverse diameter of first molar , 2 

Fore and aft diameter of second molar ^ ~'i 

Transverse diameter of second molar 2 

Fore and aft diameter of third molar 3^ 

Transverse diameter of third molar 2 

In numy respects the lower jaw of Notharctus resembles that of some of 
the existing American monkeys quite as much as it docs that of any oi the 
living pachyderms. Notharctus agrees witli most of tiie American monkeys 
12g 



e 



90 

ill tlie union of llie rami of tlie jaw at the sj'inpliysis, in the small size of the 
condyle, in the crowded condition of the teeth, and iu the number of incisors, 
canines, and true molars, wliich are also nearly alike in constitution. Notharc- 
tus possesses one more premolar and the othei's have a pair of fangs. The 
resemblance is so close that but little change would be necessary to evolve 
from the jaw and teeth of Notharctus that of a modern monkey. The same 
condition which would lead to the suppression of a first premolar, in continu- 
ance would reduce the fangs of the other premolars to a single one. This 
change, with a concomitant shortening and increase of depth of the jaw, would 
give the characters of a living Cebus. A further reduction of a single premo- 
lar would give rise to the condition of the jaw in the Old World apes and man. 

IIIPPOSYUS. 

HlPPOSYUS FOEMOSUS. 

Several small fragments of jaws with teeth, discovered by Dr. Carter in 
the vicinity of Fort Bridger, are suspected to belong to a different genus of 
pachyderms from any of those indicated in the jjreceding pages. One of the 
specimens consists of an upper-jaw fragment with the molars in a mutilated 
condition. The first and second molars are the l)est preserved, and are rep- 
resented in Fig. 41, Plate VI, magnified three diameters. The first one is 
nearly entire, but in the figure is represented in a restored condition by the 
addition of the antero-external angle marked l:)y the zigzag black line. 

The upper molars bear a general resemblance in the construjction of their 
crowns to those of Anchitherium. The outer lobes are like those in the lat- 
ter, but have their outer buttress-like ridges proportionately thicker. The 
antero-intei-nal lobe is larger than that behind and conjoins it. In Anchitherium 
the inner lobes are nearly equal and isolated from each other. The antero- 
median lobe, as existing in Anchitherium, in the present fossil is completely 
connate as part of the antero-internal lobe, and the postero-median lobe of 
the former is nearly obsolete, or appears as a mere rudiment in Hipposyus. 
A strong basal ridge incloses the crown in front, behind, and internally, but 
is absent in Anchitherium in the latter position. 

The measurements of the specimen are as follows: 

Lines. 

Space occupied by the three molars T^i 

Breadth of first molar ^i 

Breadth of second molar ' oa 

■"4- 

Breadth of third molar , 2i 

Width of first molar transversely 3i 



91 

The other specimens aeeompanyiiig the tbnner, and siisixTled lo Ixdoiig to 
the same species, consist of fragments of three lower jaws, containing each 
one or two molar teeth. One of the specimens contains the first and second 
molars and the remains of the last one. The portion of jaw is like the corre-. 
sponding portion in Notharctus, but is thicker and the teeth are stouter. The 
teeth are considerably worn, as represented in the view of the triturating sur- 
face of the second molai- in Fig. 38, Plate VI, magnified two diameters. The 
crown is ol)long square, and consists of two divisions, each of which, in tlie 
unworn condition, presented au acute crescentoid summit In the abraded 
condition the divisions present two broad, semi-lunar tracts of dentine con- 
tinuous with each other. The tracts embrace, internally, shallow enameled 
recesses, of which the posterior is much the larger. The contiguous horns 
of the tracts are continuous upon a tubercle at the inner part of .the crown 
just in advance of the middle. The posterior horn of the posterior crescent 
is likewise continuous, with a tubercle at the postero-internal angle of tlie 
crown. Externally the latter is bounded by a basal ridge, and an element of 
the same occupies the postero-internal angle of the crown. 

Measurements of the specimen are as follows : 

Liues. 

Depth of jaw below the middle molar i'>^ 

Space occupied by the three molars •• 

Breadth of crowu of first molar 2 J 

Width of crown of first molar 2 

Breadth of crown of second molar ....'. ^ 3 

Width of crowu of secoud molar 2^ 

A second specimen consists of a nearly corresponding portion of another 
jaw containing the first and second molars. The jaw-fragment is of greater 
depth than in the former, but otherwise is about as robust, and the teeth are 
nearly of the same size. The measurements are as follows: 

Liues. 

Depth of jaw below middle molar Sf 

Breadth of crown of first molar 23- 

Width of crown of first molar " 2^ 

Breadth of crown of second molar 2^ 

Width of crowu of second molar 2J 

Two additional specimens consist of portions of both rami of the lower jaw 
of a younger animal than the preceding, but only one contains a single tooth, 
the first molar, which is represented in Fig. 39, Plate VI, magnified two 
diameters. The rami of the jaw are of more slender proportions than indicated 



92 

hy the fragments above descril)ed, but are nearly as thick ; and the retained 
tooth is of the same size and form as its fellow in the fragments of older jaws. 

One of the rami contains the fangs of the complete molar series, together 
with part of the canine alveolus, which is close to the former. The number 
of premolars I cannot determine with certaintJ^ If tliree, the first of the 
series is larger than the second, and has its fangs more widely separated. If 
the number is four, the anterior two have each a single fang. 

Perhaps the latter is the true condition, which accords with that attributed 
to Limnotherium by Professor Marsh. 

Three vasculo-neural foramina are situated at the outer part of the ramus: 
one just back of the position of the canine alveolus ; a second below the 
interval of the back two premolars, and the third beneath the first molar. In 
the opposite ramus the latter is below the last premolar, and it occupies the 
same i)osition in the former two specimens. 

The first molar tooth retained in one of the rami agrees with the descrip- 
lion of those in the older jaw-fragments. Fig. 38, Plate VI, represents the 
right second molar much worn ; and Fig. 39 represents the first left molar 
in a much less abraded condition. 

Measurements from the two rami of the lower jaw just described are as 
follows : 

Lilies. 

Space occupied by the premolar aud molar series IGJ 

Space occupied by tbe molar series 9 

Depth of jaw below the premolars 5 

Depth of jaw below the middle molar 4| 

Breadth of the first molar 3 

Width of the first molar 2^ 

Figs. 1, 2, Plate XXVII, represent a specimen of a tooth recently discov- 
ered by Dr. Carter on Grizzly Buttes. It appears to be a first upper true 
molar of Hippcmjus formosus, and is scarcely worn. It was found isolated 
and unaccompanied by any other pieces which could be reasonably atti-ibuted 
to the same animal. From the comparative perfection of its crown, its con- 
stitution is more evident. It resembles in miniature the corresponding teeth 
of Anchitherium, and ditfers especially in the less proportionate development 
of the median lobes of the crown, in the greater degree of production of the 
basal ridge, in the more intimate union of the inner lobes and their more 
sloping character externally, in the more isolated condition of the postero- 
median lobe from the contiguous inner one, and in the more wrinkled condi- 



93 

tion of all the lobes approaching the base of the crown. The transverse 
diameter of the latter is J of an inch; its fore and aft diameter externally ^ 
of an inch. 

HiPPOSYUS ROBUSTIOR. 

A lower-jaw fragment containing a single tooth, obtained by Professor 
Hayden on Henry's Fork of Green River, apparently indicates a more robust 
■species of the same genus as the former. I at first attributed the specimen 
to a species of Notharctus, with the name of JV. rohustior, but a comparison 
of the tooth, represented in Fig. 40, Plate VI, with those o'i Hipposyus fonno- 
sus, Figs. 38, 39, will at once suggest the probability of its pertaining to a 
larger species of the latter genus. Perhaps' the specimen may belong to a 
more robust individual of the same species. 

The jaw-fragment is too imperfect to ascertain anything in regard to its 
anatomical characters other than its thickness. Below the second molar it is 
J of an inch thick; in the specimens attributed to H. formosus it ranges in the 
same position from 34^ to 3J lines in thickness. The second molar tooth is 
3i lines broad and 2^ lines wide. 

Order Prohoscidea ? 

Large quadrupeds with fivettoes to the feet ; molar teeth with transverse 
ridges; femur without a third trochanter; nose prolonged into a cylindrical 
trunk or proboscis. 

UINTATHERIUM. 

While encamped in Dry Creek Cafion, forty miles to the east of Fort 
Bridger, Drs. Carter and Corson spent a day in traversing a most desolate 
region to some buttes about ten miles farther to the east. They returned to 
camp after sundown laden with fossils, among which were the remains of the 
largest animal which had yet been brought to our notice from the Bridger 
Tertiary beds. '^J^hese remains consist of the cranial portion of a skull with 
fragments of both jaws attached to the same matrix, a nearly complete arm- 
bone, and fragments of other limb-bones. A notice of these remains, attrib- 
uted to a pachyderm with the name of Uintathcrium rohustum, was com- 
municated in a letter to the Academy of Natural Sciences of Philadelphia, 
and was published August 1, 1872. 

On the jJrevious day to the discovery of the remains of Uintatherium, 
while engaged in the search for fossils along the buttes, al)ou( a mile to the 



94 

east of our camp, Dr. Corson called my attention to a large tusk which he had 
found mingled with some drift-pebbles that had tldlen from the top of the 
butte. In the tusk I thought I recognized the canine of a large carnivore 
related to the extinct saber-toothed tiger of Brazil. On further search, we 
iound a j)ortion of the opposite tusk, an isolated molar supposed to belong to 
Uintatherium, another of Palseosyops, and the scale of a ganoid fish. 

In tlie same letter above mentioned, the large tusks were described and 
attributed to a carnivore with tiie name of Uintamastix atrox. 

On our return to Fort Bridger, while examining and discussing the fossils 
collected in our expedition, the question arose whether the large tusks did not 
pertain to the same animal I have named Uintatherium. Our specimen of 
the skull of the latter did not assist the determination of the question, as the 
facial portion was wanting, excepting small fragments of the back of the jaws 
containing the last molar teeth. While admitting the probability of the tusks 
pertaining to Uintatherium, from their being so unlike those of any known 
pachyderm, and from their near resemblance, both in form and size, to ihose 
of the great extinct Machairodus of Brazil, I thought the weight of evidence 
was in favor of their reference to a carnivore. The finding of a molar tooth 
of Uintatherium in association with the tusks appeared to me not to outweigh 
this evidence any more than the association with them of a molar of Palgeo- 
syops. 

Professor Marsh has published several notices in the American Journal of 
Science of the remains of large mammals from the Bridger Tertiary forma- 
tion, which appear to be related with Uintatherium. 

In June, 1S71, he reported the discovery of bones of a large animal which 
he referred with doubt to Titanotherium, with the name of T. anceps. From 
some additional remains, in a foot-note of July 22, 1872, he refers them to a 
proboscidean under the name of Mastodon anceps. This is corrected in an 
erratum of August 19, referring the animal to a new genus with the name 
of Tinoceras anceps. September 21, he j^ublishcd a notice of a new species 
with the name of Tinoceras grandis, founded on portions of a skull and teeth, 
&c. Of this he observes, " The skull is proportionately very small, and indi- 
cates one of the most remarkable animals yet discovered. It sujiports a pair 
of short horns, and has also two powerful tnsks, which, in size, shape, and 
direction, resemble the canines of the walrus." 

More recently, September 27, Professor ]\Iarsh has published a "notice of 
son>e remarkable fossil mammals," which are referred to two species of a new 



95 

genus with the names of D'mocerus vurahiLh and I), lacusttis. OC tin; skull 
ot this genus, he observes that it presents a most remarkable combination of 
cliaracters. "It is wedge-shaped, elongated, and <|uite narrow, especially in 
front, aiul was armed with horns and huge decurved canine tnsks. The tt)p 
of the skull, moreover, is deeply concave, and has around its lateral and pos- 
terior margins an enormous crest. On the frontal bones, above the orbits, 
and in advance of the lateral crest, there is a pair of very large horn-cones, 
just behind and above the canines. These are directed upward and outward, 
and their summits are obtuse and nearly round. They are solid, except at 
the base, wdiich is perforated by the upper extremity of the canine. Near 
the anterior margin of the nasals there is still another pair of horn-cones, 
which are near together, and have obliquely compressed summits. The nasal 
opening is small. The premaxillaries are slender and without teeth. The 
upper canines are greatly elongated, slightly curved, and compressed longi- 
tudinally. The lower portion is thin and trenchant. Behind the canine is a 
long diastema, t-bllowed by a series of six small teeth. The molars have their 
crowns composed of two transverse ridges, separated externally, and meeting 
at the inner extremities. The skull measures about 28i inches long and 8^ 
inches in width over the orbits. The canine is 9:^ inches in length below 
the jaw, G4 millimeters in longitudinal diameter at base, and 25 millimeters 
in transverse diameter. The last upper molar has an antero-posterior diameter 
of 36 millimeters." 

It appears to me that the brief description of the skull and molar teeth of 
Dinoceras applies so closely to the corresponding parts of Uintatherium as 
to render it probable they are of the same genus. The description of the 
tusks of the former also equally well apply to those of Uintamastix, so as to 
lead me to suspect that this may likewise be the same as Uintatherium. It 
is probable, too, that should the latter not be the same as Dinoceras it may 
prove to be the same as Tinoceras, or perhaps the Eobasileus s. Loxolophodon 
of Professor Co]^)e. 

The characters of Uintatherium, as expressed in the material at our com- 
mand, are so peculiar and unlike those of any other known animal as to ren- 
der its ordinal affinities obscure. From the form and constitution of the 
molar teeth alone, I should have viewed the genus as pertaining to the odd- 
toed pachyderms. If the remains noticed by Professor Marsh under the 
name of Dinoceras belong to the same animal, the presence of horns in pairs 
to the head would render such a reference improbable. Professor Marsh 



96 

observes of Diiioceras and the related Tinoccras, that they have the vertebral 
and limb bones very similar to those of recent proboscideans, but refers them 
to a new order vvitli the name of Dinocerea. 

The form of tlie thigh-bone and the short tarsal bones of Uintatherinm 
\\ould appear to indicate limbs and feet most nearly constructed like those of 
the elephant. I have provisionally placed the animal in the order of Probos- 
cidea, leaving to Professor Marsh the determination of its true position from 
the more abundant materials at his command. 

UlNTATHERIUM KOBUSTTIM. 

The remains which are specially to be regarded as characteristic of the 
animal above named, and from which it was originally indicated, consist of a 
mutilated cranium, to the matrix of which there adhere'd portions of both 
jaws, containing all the last molars and an isolated molar. A nearly com- 
plete humerus, together with some less well preserved specimens found in 
association with the former, are supposed to have pertained to the same 
individual. 

A small fragment of the upper jaw, containing the last molar tooth, is rep- 
resented in Fig. 8, Plate XXV. The tooth, also represented in Figs. 6, 7, 
of the same plate, and Fig. 30, Plate XXVII, has the crown composed 
of a pair of wide pyramidal lobes projecting from a broad expanded base. 
The lobes extend across the crown, conjoining internally and diverging ex- 
ternally in a V-like manner. They project at their outer extremities in promi- 
nent points, and also form together a prominent point at their conjunction 
internally. The outer extremity of the anterior lobe is the most prominent 
of the three points of the crown. The outer extremity of the posterior 
Iol)e is the least prominent of the three points, while that at the conjunc- 
tion of the lobes is scarcely more so. The acute summits of the lobes 
between the points arc transversely concave, and are worn off on their anterior 
slope so as to present narrow tracts of exposed dentine. The posterior slope 
of the lobes is slightly concave ; and the valley between them is triangular, 
and opens outwardly. 

From the posterior slope of the inner part of the back lobe of the crown 
there projects a rounded tubercle about half-way between the basal ridge and 
the pointed conjunction of the lobes. A second rounded tubercle occupies 
the entrance of the triangular valley between the lobes. 

A stout basal ridge embraces the crown in front and behind, and in a 



97 

reduced condition continues interruptedly on the inner and outer parts. In 
"outline the base of the crown is ovoidal, with the narrower extremity corre- 
sponding with the outer part of the anterior lobe. The tooth is inserted by 
a pair of fangs widely compressed, conical, and convergent internally. The 
transverse diameter of the crown of the last upper molar is 20 lines ; its fore 
and aft diameter is nearly 18 lines. Tlie description of the upper molars of 
Dinoccras mirabilis, and the size of the last one, as given by Professor Marsh, 
so well apply to the tooth above described as to lead me to suspect that the 
animal so named is the same as Uintatherium rohustum. 

The fragments of both sides of the lower jaw of the latter, represented in 
Fig. 11, Plate XXV, and Figs. 32, 33, Plate XXVII, contain the last molar tooth, 
also represented in Figs. 9, 10, of the former plate, and Fig. 31 of the latter. 
The tooth has an oblong square crown, rounded at the corners and moderately 
constricted at the middle laterally. It is inserted in the jaw by a pair of 
wide, compressed conical fangs. 

The crown is composed of three lobes, with oblique intervening valleys, 
which receive the pair of lobes of the corresponding upper tooth when closed 
upon the lower one. 

The anterior lobe forms nearly half the crown, and rises internally in a 
point, which is the most prominent part of the tooth. The front and back 
surfaces are sloping, and the former is transversely concave, and bounded by 
a short, oblique basal ridge. The inner and outer surfaces of the extremities 
are convex, and extend to the bottom of the crown. The acute summit 
curves downward and outwai'd from the inner point. It is worn off on the 
posterior slope with a more forward direction externally, and exhibits a nar- 
row tract of exposed dentine. The prominent point of the inner extremity 
is notched just below the summit postero-internally. 

The posterior and middle lobes of the crown are nearly of the same size 
and prominence. The posterior lobe is separated from the anterior lobe 
internally by a deep, angular notch, and diverges from it externally. It 
forms the posterior convex surface of the crown, and has an anterior sloping 
surface defined from it by a ridge curving from the inner side backward and 
outward, and then becoming continuous, with a basal ridge sweeping down- 
ward to the bottom of the middle lobe of the crown externally. The middle 
lobe appears like an ovoidal wedge introduced from the outer side, and sepa- 
rating the anterior and posterior lobes. Its summit is worn off with a slight 

posterior slope, and exhibits an exposed tract of dentine. 
13g 



98 

A thill, incoiispiciious basal ridge occupies the inner half of the liack part 
of (lie crown ; a thicker festoon extends from the summit of the posterior 
lobe externally to the bottom of the middle lobe ; and a short, prominent 
ledge occupies the middle of the front of the crown. 

The fore and aft diameter of the crown of the last lower molar is 1^ inches; 
the transverse diameter in front is 14 lines; behind, 12^ lines. 

Associated with the other specimens referred to Uiutatherium, there was 
found the isolated tooth represented in Fig. 12, which I suppose to be a tirst 
upper molar. It has the same constitution as the last upper molar above 
described, but is smaller. In the present condition of the crown, the poste- 
rior lobe is more prominent than the anterior, and it exhibits a broad horseshoe- 
shaped exposed tract of dentine extending upon the summits of both lobes. 
The dentinal surface is concave from side to side, and inclines forward. The 
outer extremity of the anterior lobe, broken in the specimen, is considerably 
thicker than that of the posterior lobe. Back of the inner conjunction of the 
lobes, just below the summit, the rounded tubercle is visible, such as exists 
in a corresjionding position in the last molar. It is worn so as to exhibit a 
small circular islet of dentine. 

The basal ridge, as in the last upper molar, is thick in front and behind, 
but feeble upon the inner and outer sides. 

The first molar was inserted by a pair of fangs. The antero-posterior 
diameter of the crown is 16 lines ; the transverse diameter at the hinder lobe 
is 15i lines. 

The upper molars of Uintatherium above described, bear considerable 
resemblance to the last upper molar of Lophiodon lidrisiense, as represented 
in Fig. 3, Plate XVII of Gervais's Paleontologie. They differ especially in 
the absence of the offset from the middle of the anterior part of the front lobe 
of the crown. 

The upper molar teeth, attributed by Gervais to L. parisicm^e, represented 
in his Figs. 3, 4, so nearly resemble the corresponding teeth of Uintatherium 
and so decidedly differ from those of Lophiodon, as characterized from the 
typical species L. isselense, that it may be questioned whether it belongs to 
the same genus. The characters presented by the teeth referred to L. parisi- 
ense, are suthcicntly distinct and well marked to consider them as indicating 
a genus differing from Lophiodon and Uintatherium, and probably more nearly 
related with the latter than the former. 



9!) 

The cranium of Uiiilaihcruiiu, represented in Fig. 1, Plulc XXVI, is of 
rcnuirkablc form and unlike tliat of any other known animal. The specimen, 
though much mutilated, is yet sufficiently well preserved to give us sonic 
notion of the peculiarities of the skull. 

The top of the cranium presents a deep basin-like concavity separated on 
each side from the temporal fossfe l)y a wide projecting crest. The entire 
extent ot" tliis cannot be determined from the broken condition of its edirc in 
the specimen, l)ut on one side it projects obliquely outward and upward for 
three inches beyond the inner surface of the temporal fossa. Posteriorly, the 
crest is continuous with a thick broken border extending across the top of 
the occiput so as to make it api)ear as if the lateral projections of the 
cranium were continuous behind. The depth of the supra-cranial hollow in 
the specimen is upward of several inches, and was, no doubt, greater in the 
complete skull. 

The temporal fossa is a long deep concavity overarched by the wide lateral 
crest separating it from the supra-cranial hollow. Its lower part spreads out- 
wardly on a l:)road ledge extending from the lateral occipital border forward 
upon the upper surface of the zygomatic root. This ledge resembles the 
long extension backward of the zygomatic root in the bear, and in like man- 
ner it projects over the auditory archway and the contiguous processes. 

From the fractured condition of the specimen, I am unable to ascertain the 
])osition of the squamous suture, and this may be said also of other sutures. 
The temporal surface as formed Ijy the squamosal plate and the iieighb(jring 
portion of the parietal is pierced with a number of large vascular foramina. 
The occipital surface is broad, and it slopes inwardly from above to the occi- 
pital foramen. 

The large condyles project strongly backward and downward, and are not 
in the least degree sessile, but well defined from the occipital surfiace by a 
deep groove. Their articular surface is broad, being within a fourth as great 
as the depth, and the flexure near its middle appears less pVonounced than 
usvial. The articular surfaces are not prolonged below on the basi-occipital, 
and the condyles in this position are separated by a deep notch twenty lines 
from each other. 

The basilar process is broad and thick, and moderately tapering. Its undcM- 
surface is transversely convex, especially antericn-ly. On each side ol tlie 
middle it presents a broad rough eminence for muscular attachment. 



100 



The relative positions of the paramastoid and mastoid processes, the audi- 
tory archway, and the post-glenoid tubercle are nearly the same as in feline 
animals, but here the resemblance ceases. 

The paramastoid process is a comparatively slight roughened eminence, 
situated just above and external to the position of the fore part of the con- 
tiguous condyle. It is separated from the mastoid process by an archway 
directed inward and forward to the space usually occupied by a tympanic 
bone, but whicli in the specimen is filled with the matrix of the fossil. 

The mastoid process, though much broader and longer than the paramastoid, 
does not project so much downward as the occipital condyle. It is semicir- 
cular below and roughened, and is compressed from without inwardly. Its 
outer surface presents a median fossa at the base. 

The auditory archway expands outwardly in a funnel, and below is 
partially contracted by a short ledge, a process of the tympanic, projecting 
from the mastoid process. 

The root of the zygoma is of great strength, and has, projecting downward 
from it, a post-glenoid tubercle of extraordinary size. The process is 2^ 
inches in width, and projects externally in a rounded knob. Its lower part 
forms a slightly irregular flat sfirface, just above which, the tubercle is 1^ 
inches thick. Its inner extremity slopes upward and inward. 

The glenoid articulation is transverse, and its surface straight in this direc- 
tion. Upon the post glenoid tubercle the surface is vertical until it curves 
for\yard and upward to the anterior edge of the zygomatic root. Its forward 
extension is about equal to that downward. The glenoid articulation is evi- 
dently adapted especially to a hinge-like motion, though not so restricted as 
that of carnivores. 

Measurements derived from the cranial specimen of Uintatherium are as 
follows : 

Incbcs. 

Breadth of the craDium at the outer part of the post-glenoid tubercles 10 

Breadth of the crauium at the mastoid processes 7^ 

Width of the basi-occipital in front of tbe occipital condyles 2^ 

Breadth of the occipital condyles together C 

Breadth of each coud\ le 2^ 

Depth of each condyle 3 

Distance between the condyles or breadth of the occipital foramen 2J 

Length of the temporal fossa fore and aft ■ 7 

Breadth of crauium between the temporal fosste where deepest, about . -tj 

Depth of cranium from bottom of supra-cranial basin to basi-occipital, about 4J 



101 

The lower-jaw specimens of Uintatlierium are represented in Fijr. 11, 
^late XXV, and Figs. 32, 33, Plate XXVII. Both contain the last molar, and 
the better-preserved one also contains the fangs of the preceding molars and 
the last premolar. The space occupied by the molars is 4 inches, which 
appears small in relation with the size of the animal. The space which was 
occupied by the second molar is nearly as broad as the last molar. The 
crown of this measures li inches. The space which was occupied hy the 
first molar is little more than three-fourths of an inch, thus showing a great 
difference in the size of the first, compared with that of the succeeding 
molars. 

The body of the jaw is of robust proportions. Its depth beneath the fore 
part of the last molar is 3^ inches ; its thickness just above the I'ounded base 
is nearly 1^ inches. A strong obtuse ridge sweeps from the root of the coro- 
noid process downward and forward along the base of the jaw beneath the 
position of the molars. 

Back of the position of the latter, the jaw bears more resemblance to the 
corresponding portion in the great felines than it does to that of ordinary 
pachyderms. 

The coronoid process is a broad curved plate rising immediately in advance 
of the condyle, as in the lion. As in the latter, likewise, it is impressed ex- 
ternally with a deep masseteric fossa extending below on the body of the 
bone, but becoming more abruptly shallow approaching the base. 

Tlie entrance to the dental canal is nearly on a line with the alveolar bor- 
der, 2^ inches above the base of the jaw. 

The condyle is a transverse convexity 2^ inches in breadth, and rather 
more than an inch in width at the middle. It is narrowest internally, the re- 
verse of the condition in the lion. 

The breadth of the jaw back of the molars is estimated to be about 5 
inches ; the breadth of the coronoid process at base is about 3 inches. 

The specimen of a mutilated atlas, represented in Fig. 2, Plate XXVI, and 
Fig. 34, Plate XXVII, supposed to belong to Uintatherium, was found by 
the writer on the buttes west of Dry Creek Canon. It accords in size with 
the cranium of Uintatherium above described, and fits the occipital con- 
dyles as well as the bone of one individual might be expected to adapt itself 
to that of another. 

The atlas is very unlike that of any ordinary familiar animal. While it is 
much smaller than that of a mastodon, it includes a canal of even greater 



102 

capacity. Unlike tliat ot" tlie animal just named, it is quite circular, and 
about 3J inches in diameter. The portion occupied by the spinal cord is 
absolutely larger than in the mastodon, and it is but slightly defined, from the 
portion for the pivot of the axis, by slight tubercular elevations for the trans- 
verse ligament. 

The atlas is proportionately longer than in the mastodon, but is of less 
width. The inferior arch beneath is nearly flat, and without a hypapophysis, 
and on each side presents a superficial, rough prominence ["or muscular 
attachment. The neural ai'ch is comparatively long and narrow, and appears 
to be devoid of a protuberance. 

The articular concavities for the occipital condyles are deeper and more 
strongly sloping than in the mastodon. They are separated below by a deep 
notch at the fore part of the inferior arch. Above, they are removed from 
each other double the distance. 

The articular facets for the a.xis are ovoidal, slightly concave, and incline 
at an angle of nearly 45°. They are separated below for a couple of 
inches by the thick back liorder of the inferior arch of the atlas. Above, 
they are separated by the long semicircular edge of the neural arch. 

The inferior arch of the atlas-supports a facet for the odontoid process of 
the axis, which is distinct from the articular flxcets on each side of the latter. 

The transverse processes are unlike those of the elephant and mastodon, 
and are more like those in ordinary ruminants, &c. The ends are broken 
off, but they appear as broad, thick plates, extending fore and aft, though not 
the entire length in either direction. 

The canal for the vertebral artery perforates the transverse jjrocess fore 
and aft from the back half of the upper to the anterior part of the lower sur- 
face. As a groove, it then turns upward in advance of the root of the trans- 
verse process, and is directed inward to a canal perforating the neural arch 
anteriorly above the position of the articular concavities for the occipital 
condyles. 

Approximative measurements of the atlas are as follows: 

IncbcB. 

Breadth between the outer edges of the anterior articular concavities (>i| 

Depth of the atlas posteriorly from above downward 4.J 

Breadth between the outer edges of the posterior articular facets . . (>i 

Fore and aft extent of the inferior arch at the middle li 

Length of the atlas laterally 5 

Diameter of spinal foramen from above downward 'A^ 

Diameter of spiual foramen transversely ' ^g 

Breadth fore and aft of transverse processes , 3i 



103 

The hiunerus of Uinlatherium, of which the aiitorior view of a sprciinni 
is given in Fig. 3, Plate XXVI, is very unlike that of" aii}' other tamiliar 
animal. In its peculiarity of form it presents no very evident relationship 
with that of the larger pachj-derms, odd or even t(jed, tlic proljoscideans, or 
the ruminants. It is shorter, in proportion with its breadth, than in the 
elephant. The shaft is narrowest and most nearly cylindroid at the union of 
the upper two-thirds wilii the lower third. The upper part is prominently pro- 
duced outwardly to support a long triangular deltoid tract, the point of which 
reaches below the middle of the bone. The deltoid surface loolvs outwardly 
and backward, and is nearly flat, except below where it is depressed. The 
back of the shaft presents a broad, nearly flat surflice, dividing near the mid- 
dle in two portions, of which one extends nearly straight downward, while 
the other portion winds outward and forward below the deltoid tract to the 
front of the distal extremity. 

The surface of the shaft internally to the deltoid tract is wide and sloping 
inwardly. It is slightly depressed on the deltoid expansion, but elsewdiere is 
nearly flat transversely, and it narrows downward in its extension to tlie in- 
ternal epicondyle. 

The outer or greater tuberosity of the humerus and the contiguous portions 
of the head and deltoid tract are destroyed in the specimen. The inner side 
of the head of the bone presents a broad depressed tract rising on the shaft 
Ijelow in a triangular protubei-ance, which answers to the ordinary internal 
tuberosity of the humerus. From the apex of the angular protuberance, a 
ridge descends the shaft defining the inner or anterior aspect of the bone 
from the posterior. 

The head is most convex from 1)efore backward, and in this direction it 
looks as if, iu the complete condition, it had not been greater than the trans- 
verse diameter. 

The external epicondyle is thick and prominent, but is of comparatively 
little vertical extent. Its summit forms a thick, rough eminence, extending 
an inch externally to the capitulum and several inches in width above it. Its 
outer face presents a l)road crescentoid surface directed obliquely outward 
aiul downward. It is rougii and pierced with vascular foramina, and is 
divided into several facets for the attachment of the extensors of the lore- 
arm and the external lateral ligament. 

The internal epicondyle is a comparatively low, thick, and rough pntnii- 



104 

nence, defined from the trochlea by a wide, pitted groove. Its upper part is 
destroyed in the specimen. Its l>aclv part barely projects posterior to the 
position of the trochlea. 

Above the distal articulation, where the bone is expanded to form the outer 
epicondyle, it is depressed into a l:)road and unusually deep concave fossa. 

The olecranon fossa is broad and moderately deep, but is not much ex- 
tended by the protrusion backward of the epicondyles. 

The distal articulation of the humerus presents a well-rounded capitulum 
on the outer condyle and a broad trochlea extending from it on the inner 
condyle. The capitulum is convex and narrows behind on a ridge separating 
the posterior prominence of the outer epicondyle from the trochlea. The 
trochlear groove is directed obliquely from the fossa in front of the outer epi- 
condyle downward and inward, then backward, upward, and outward to the 
olecranon fossa. 

The measurements of the bone are as follows : 

Inches. 

Length of the buinerus internally 20J 

Width ti'ansversely of the head 4^ 

Width of shaft at the middle from the lower part of the deltoid tract to the pos- 

tero-iiiteraal border i^ 

Thicl;ness of shaft at middle of same position 2^ 

Circumfereuce of narrowest part of shaft 9^ 

Diameter transversely of narrowest part of shaft 2g 

Diameter autero-posteriorly of narrowest part of shaft 3 

Breadth at the epicondyles , , , . - 7f 

Breadth of distal articulation 5^ 

The mutilated upper extremity of the femur, represented in Fig. 4, Plate 
XXVI, was found by Dr. Corson, on the buttes west of Dry Creek Caflon, 
a dozen miles from the former specimens. It is suspected to pertain to Uin- 
tatherium, though it would ajjpear to have belonged to a larger animal, and 
perhaps a different species, than the one to wdiich the cranium and humerus 
are referred. The specimen has about the same si^e and form as the corre- 
sponding part in the elephant, but the great trochanter is destroyed. The 
length of the fragment is about 11 inches. The head is 5 inches in diameter, 
but its surface is too much mutilated in the specimen to determine whether 
it possessed a jtit for the attachment of a round hgament, or whether it is 
absent as in recent proboscideans. The outer border of the shaft below the 
position of the great trochanter is 2g inches thick. From the appearance of 



105 

the specimen, tlie I'eimir in its entire condition luis evidently resembled that 
of the elephant more than it does that of the perissodactyles. 

The mutilated distal end of a femur, represented in Fig. 5, is also supposed 
to belong to Uintatherium, though it did not pertain to the same individual as 
the preceding specimen. It was found in the same locality, but at a distance 
from the former, and was derived from a different stratum, as it has an adher- 
ent friable sandstone matri.x, while the other has an adherent indurated clay 
matrix. It is considerably smaller than the corresponding part of the femur 
of the elephant, and is very different in anatomical character. It is propor- 
tionately less thick. The shaft above the articulation, on the front and at the 
sides, presents a continuous transverse convexity, without any depression 
whatever above the position of the trochlea. The posterior surface in the 
same direction, between the position of the low epicondyles, is concave. 

The loss of part of the outer condyle prevents a comparison of Ijreadth 
with the inner one, but this is more prominent posteriorly than the former. 
The trochlea is shallow and but feebly prominent anteriorly in comparison 
with that in the elephant. Its articular surface is continuous with that of 
the inner condyle, and also that of the outer one, so far as it is preserved in 
the specimen, without the slightest definition. The intercondyloid notch 
commences at the bottom of the trochlea and gradually widens backward and 
upward with a curve outward. 

The length of the fragment of the femur is 6^ inches. The breadth be- 
tween the epicondyles is about 5 J inches ; the thickness of the inner condyle 
and trochlea together is 5 inches, and the depth of the trochlea along its 
groove is 2J inches. 

Several large tarsal bones, found together on the buttes to the west side of 
Dry Creek Canon, may perhaps belong to Uintatherium. They consist of a 
calcaneum, astragalus, and cuboid bone of the left foot, and fit well enough to- 
gether to have belonged to the same individual. In form and 2)roportions, 
though somewhat peculiar, they more nearly resemble those of tlie mastodon 
and elephant than of other known animals. 

The calcaneum, of which an upjjer view, half-size, is given in Fig. 6, 
Plate XXVI, is remarkable for its short robust character. The tuber calcis, 
in comparison with that in the ordinary proboscidians, is very short. The 
breadth of the tuber exceeds its length, and the depth exceeds the breadth. 
The thickened extremity narrows below and is continuous with the thick 
longitudinal plantar ridge. The upper part of the tuber inclines nearly 
U u 



lOG 

slj-aiglit I)ackwar(l I'rom tlie articulation. Its outer surtace l()rms part of an 
irregular plane with the fore part of the boue. 

The sustentaculum is thick and three-fourths the length of the bone. Tlie 
groove beneath for the flexor-tendons is well marked. Tlie articular surface 
it supports for the astragalus, is larger than that on the body of the bone. 
The groove separating the articular surfaces for the astragalus nearly occu- 
pies the middle of the bone Both surfaces are flat in front, but convex back- 
ward behind 

No articular surface exists for the fibula. At the fore part of the bone 
there is a small articular facet for the cuboid. The remaining portion of the 
front surface forms a deep and wide irregular plane. 

The astragalus, of which upper and lower views are given half-size in 
Figs. 7, 8, Plate XXVI, resembles that of the ordinary proboscideans. The 
bone is irregularly square, with nearly equal horizontal diameters, and of less 
thickness than these. 

The ui)per articular face has nearly the shape of that in a mastodon, but 
is rather more depressed posteriorly. The fibular extension holds about the 
same proportion to the tibial surface as in the animal named. 

The calcanean articular surfaces are the reverse in their comparative size 
to what they are in the mastodon, the inner one being the larger. Both are 
also more concave fore and aft than in that animal. 

The navicular articular surface is proportionately deeper in comparison with 
its width tlian in mastodon, and is well defined outwardly from the cuboid 
articular facet. 

The cuboid is triangular in outline, with rouiraed angles, and with the 
thickness more than iialf the breadth or depth. Proximally it presents a 
double articular facet, of which the division for the astragalus is larger than 
that for the calcaneum. The former division is continuous with a narrow 
fiicet on the inner side for the navicular. Distally the l)onc also presents a 
doulile articular tiicet, the divisions forming an obtuse angle. 

The measurements of the tarsal bones are as follows: 

Calcaneum, 

Lines. 

Length of calcaueum 413 

Breadth at fore part 39 

Depth at fore part externally 31 

Length of tuber c.ilcis from the outer articular facet above . l-'O 

Breadth transversely of the outer articular facet for the astragalus 14A 



e 



107 

Li Ilea. 

Breadth fore ami aft of the outer articuhir facet for the astragahis 'S3 

Breadth trausverselj^ of the iuuer articular facet for the astragalus . . , 18 

Breadth fore and aft of the inner articular facet for the astragalus 2i 

Breadth transversely of the articular facet for the cuboid 14 

Breadth vertically of the articular facet for the cuboid 10 

Astragalus. 

Lines. 

Greatest breadth fore and aft of the astragalus at inner side uO 

Greatest breadth transversely of the astragalus 52 

Greatest thickness of astragalus 32 

Breadtli of tibial articular surface at niidillo transversely ' 38 

Breadth of tibial articular surface at middle fore and aft 32 

Breadth of articular facet for scaphoid 40 

Depth of articular facet for scaphoid 28 

Cudoid. 

Linos. 

Depth of the cuboid 25 

Breadth of the cuboid interiorly 25 

Length of the cuboid at center 15 

The canine tooth, originally described and referred to a carnivore with the 
name of Uintamastix atrox, is represented in Figs. 1 to 3, Plate XXV. T 
specimen is broken into two pieces, is mutilated at the point, and has lost 
apparently several inches of the base. In its perfect state the tooth approxi- 
mated a foot in length, of which it now retains about three-fourths. It is saber- 
like in general form — long, laterally compressed cyliudroid, and moderately 
curved. It appears more curved at the base, and from this position, also, has a 
somewhat outward deflexion, so that the tooth in its course curved forward and 
downward with an outward divergence. Laterally from the base it gradually 
tapers to the point ; fore and aft it gradually narrows to near the lower third, 
when it becomes slightly expanded before tapering, so as to assume the shape 
of a lance-head. This likeness is rendered more striking internally by the sur- 
face being concavely impressed in front and behind the axis extending toward 
the trenchant borders of the lance-head extremity. Externally, it is impressed 
in like manner to a less extent posteriorly, but not anteriorly. Above the 
lance-head extremity of the tooth it is obtusely rounded in front and Ijehind, 
and in this position is eUiptical in transverse section, as represented by tlie 
(ludine, Fiir. 5. A section near the middle of the lance-head extremitv has 
llie form represented in Fig. 4. 

The tooth, so far as tlie specimen extends, appears to have been invested 
willi thin enamel throughout. Externally, if reaches lo the broken edge of 



108 

the base, and, internally, appears to liave been lost from the corresponding 
position l)y erosion. Externally, it is longitudinally rugose, and the rugosity 
appears to be greater toward tlie point, and, to some extent, is divergent 
toward the trenchant borders. Internally, the rugosity of the enamel is less 
marked, and toward the point it is worn off for several inches along the axis 
and near the borders from the attrition of an opposing lower tooth. The ex- 
tent of attrition would apparently indicate large lower canines. 

At the broken base of the specimen the borders of the exposed pulp cavity 
are nearly 4 lines thick. The fore and aft diameter of the tooth 2 inches 
below the broken base is a little under 2 inches ; the thickness is 13 lines. 
The breadth of the tooth just Ijefore expanding in the lance-head extremity 
is 1^ inches. The widest part of the latter appears to have been a couple of 
lines greater. 

The tusk above described, though apparently according in form with those 
of Dinoceras mirabiUs, as described by Professor Marsh, exhibits different 
proportions, having less breadth and greater thickness. Thus Professor 
Marsh gives as the diameters of the tusks of D. mirahilis 64 millimeters 
breadth, and 25 millimeters thickness. The tusk above described has a 
breadth of 50 miUimeters, and a thickness of 28 millimeters. 

From the description of the skull of Dinoceras given by Professor Marsh, 
as before intimated, I have been led to view the large tusks above described, 
and originally referred to a carnivore with the name of Uintamastix, as really 
pertaining to Uintatherium, and perhaps to the same species as that indicated 
by the cranial specimen referred to TJ. rohustum. 

The molar tooth of Uintatherium, represented in Figs. 13, 14, found with 
the large tusk, has the same form and constitution as the upper molars first 
referred to the genus, except that it is considerably smaller, and has no 
tubercle behind the summit of the conjunction of the lobes of the crown. 
Proportionately, also, the basal ridge is much better developed at the inner 
part of the crown, where it is continuous with the stronger ridge in front and 
behind. The antero-posterior diameter of this tooth is 11^ lines, and its 
transverse diameter is estimated at 13J lines. 

The tooth I supposed to be an upper premolar of U. rohustum; if, how- 
ever, it is a true molar, its comparatively small size, and the absence of the 
characteristic tubercle on the posterior slope of the conjunction of the lobes 
of the crown, as existing in the species just named, would indicate that it 



109 

probably belonged to a diflereiit one. Found in association with the canines 
referred to TJintamastix atrox, it may pertain to the same animal. 

Order Rodentia. 

Small qnadrupeds with clawed toes. Teeth consisting of two long curved 
incisors in each jaw ; no canines, and the molars separated from the former 
by a wide interval. 

Paeamys. 

An interesting peculiar extinct genus of gnawers of the sciurine family is 
indicated by a number of specimens, consisting of fragments of lower jaws 
with teeth, which were discovered by Dr. Carter, in the summer of 1871, in 
the Tertiary formation in the vicinity of Fort Bridger. 

As in the squirrels and marmots, the lower molars are four in number, 
and are inserted each by two fangs. They are nearly of the same size, but 
are proportionately narrower than in the animals just mentioned, as the fore 
and aft diameter exceeds the transverse, while in most sciurine animals the 
reverse condition usually exists. 

The crowns are short, square, tuberculate, and enameled. The arrange- 
ments and proportionate size of the tubercles at the four corners of the crown, 
including a concave surface, are the same as in the squirrels. 

The lower jaw is proportionately shorter and deeper than in most known 
rodents, the reduction in length being mainly due to a less development of 
that part of the bone in advance of the molars. To compensate for the dif- 
ference in length and to make room to accommodate the incisors, these teeth 
reach farther back than usual. In squirrels and marmots their posterior 
extremity reaches a short distance behind and beneath the last molar. In 
Paramys it reached further backward, upward, and externally to a level 
with the crown of the last molar. 

The jaw in advance of the molars is not only short compared with the usual 
condition in most known rodents, but the acute edge of the hiatus between 
the molars and incisors is almost on a level with the alveoli of the teeth, 
instead of forming a deep concave notch, so conspicuous a feature in the lower 
jaw of the gnawers generally. 

In sciurine and most other rodents the ridge defining the masseteric fossa 
extends far forward on the side of the jaw to a position beneath the second or 



no 

even the first molar tooth. In the rabl)U>; tlic defining ridge is comparatively 
far back, extending only to the position of the interval of the last two molars. 
In Paramys it holds an intermediate position, extending as far forward as the 
position of the third molar, where it forms a conspicuous angular prominence, 
as in the marmots. 

The mental foramen, much higher in relative position than usual in rodents, 
is situated in advance of the molars a short distance below the edge of the 
hiatus separating the latter from the incisor. 

Paramys delicatus. 

The largest species of Paramys was, perhaps, about a fourth less in size 
than the Maryland marmot, though its series of molar teeth is nearly equal 
in size, measuring three-fourths of an inch in length. It is represented by 
two specimens sent to me by Dr. Carter, consisting of portions of the right 
and left sides of the lower jaw, containing most of the molars and portions of 
the incisors. One of them is represented in Fig. 23, Plate VI, of the natural 
size. The triturating surfaces of the molars of both specimens, magnified 
three diameters, are represented in Figs. 24, 25. 

In one of the specimens. Fig. 23, two mental foramina exist, one in the 
position, previously indicated, in advance of the molars, a short distance 
below the edge of the jaw ; the other is situated lower down below the posi- 
tion of the first molar. In the other specimen the foramen exists in the lat- 
ter position, and as the jaw is broken in advance, it cannot be determined 
whether a second existed, which is, however, probable, as it is the usual and 
normal position of one. A prominent tubercle is il)rmed at the angle of con- 
vergence of the ridges which define the masseteric fossa. 

Paramys delicatior. 

A second species is indicated by a specimen consisting of the greater por- 
tion of the left ramus of a lower jaw, represented in Fig. 26, Plate VI. It 
retains the second molar tooth, the triturating surface of which, magnified 
three diameters, is represented in Fig. 27 of the same plate. The molar 
series has measured about 74 lines in length, and (he animal was about the 
size of our common grav rabbit. 

Since writing the above, I have x'eceived from Dr. Carter several additional 
specimens which I suspect belong to the same species. One of them, an in- 
termediate lower molar, is represented in Fig. 16, Plate XXVII. It suflS- 



Ill 



cinifly resembles the foolli oi" Fig. 27, Plato YI, origiuiilly reteried lo /'. 
delicatior, to pertain tt) tlu; same species, thougli it is slightly larger. 

The other specimen, apparently from the same individual, consists of a pair 
of upper molars represented in Figs. 17, 1<S, Plate XXVII, magnified three 
diameters. They have nearly the form and construction of those of the 
Sciurides. 

The fore and aft diameter of the lower molar is 1.8 lines. The fore and 
aft diameter of the upper molars is 1.8 lines, and the transverse diameter is 
2 lines. 

Pakamys delicatissimus. 

A third and still smaller species of Paramys is indicated liy a specimen 
consisting of the greater portion of the right ramus of a lower jaw contain- 
ing all the molars, and a second specimen consisting of a small fragment of 
another lower jaw containing the second molar. The first specimen of the 
natural size is represented in Fig. 28, Plate VI. A view of the triturating 
surfaces of the molars, magnified three diameters, is given in Fig. 29. The 
molar series measures J an inch in length, and the animal was about the size 
of the common gray squirrel. 

Comparative measurements are as follows : 



Leugtb of louver molar series 

Leiigtb of biatus iu advance of lower molar series 

Deptb of jaw below tbe second molar 

Fore and aft diameter of incisor 

Transverse diameter of incisor 

Fore and aft diameter of second molar 

Transverse diameter of second molar 



P. (lelica- 
tus. 



Lines. 
9 

C 

-1 
5 

14 



p. delica- 
tior. 



Lines. 



14 



P. delica- 
tissimiLs. 



Lines. 
G 

•1 

li 

H 
n 



MYSOPS. 

Mysops minimus. 

A small rodent, intermediate in size to the common mouse and the brown 
rat, is indicated by a specimen discovered by Dr. Carter at Grizzly Buttes 
and sent to the author last summer. The S])ccim('n cousists of the median 
portion of the right ramus of a lower jaw containing the last two molars, the 



112 

fangs of the others, and part of the incisor. It is represented in Fig. 31, 
Plate VI, magnified two diameters. 

The jaw in its form, proportions, and construction, and the number of teeth 
and their relative position, agree with the conditions in Paramys, but the form 
of the molars is sufficiently different to refer the specimen to a different genus, 
for which the above name has been proposed. 

The molar teeth, as in Paramys, are four in number, inserted each by 
a pair of fangs. The crowns are quadrate and invested with enamel. 
The triturating surface, instead of being constructed like tluit of the squir- 
rels, is more like that of the rats, as seen in Fig. 32, Plate VI, in which 
tiic last two molars of the specimen are represented magnified eight diam- 
eters. The crown of the third molar exhibits two transverse lobes, or 
ridges, joined by an intermediate narrow ridge, and the inner extremities of 
the lobes include a trilateral tubercle. The enamel being worn away from 
the prominences of the crown leave exposed a pair of transversely eUipsoidul 
dentinal surfiices joined by a narrow isthmus. Upon the summit of the inter- 
nal tubercle a small islet of dentine also appears. 

The last molar exhibits three transverse ridges or lobes, of which the 
anterior is the thickest, the middle one the thinnest, and the .i^osterior the 
shortest. The anterior lobe is worn so as to exhibit a transversely elliptical 
surface of dentine bordered with enamel. The middle ridge of the crown 
appears sigmoid and is unworn. The posterior lobe presents an exposed islet 
of dentine on the inner half of its length. 

The anterior molar of Mysops, like the last one, is more elongate fore and 
aft than the tw-o succeeding molars, but it is proportionately of less size than 
in the rats, and has not three fangs as in these animals. 

The length of the molar series is J of an inch. The first and fourtli 
molars are about | of a line fore and afl ; the intermediate ones about ^. The 
incisor measures about I of a line fore and aft l)y f transversely. The depth 
of the lower jaw below the second molar is 2^ lines. The length of the 
hiatus in advance of the molars is 1^ lines. 

Mysops fraternus. 

Since writing the foregoing I have received another specimen, which may 
belong to Mysops. It was found by a Shoshone Indian, and given to Dr. 
Carter. It consists of a portion of the right ramus of the lower jaw, repre- 



113 

scntrd iu Fig. 14, Plate XXVIl. It coiit;iiiis the last three molai-s, tlic trilii- 
rating surtiices of which are represented in Fig. 15, magnified eight dianieters. 

I'he jaw is proportioiaately deep and short, compared with that of Ihe ra1. 
The masseteric fossa is deep, and defined by a rectangle, the apex of wiiioh 
reaches as far forward as the position of the third molar tooth. The l)ordei- 
of the jaw at the hiatus in advance of the molars extends nearly on a level 
from their alveoli to that of the incisor. 

The molar teeth, though having the same general constitution as the cor- 
responding ones in the jaw-fragment of Mysops mini»ms, above described, 
appear sufficiently distinct to pertain to another species, and I have therefore 
distinguished it as such with the name of J/, fraternus. 

In the jaw-specimens of both species the molars are worn nearly to the 
same extent. In comparing the corresponding teeth, it will be seen that the 
third molar in M. fraternus has a greater breadth fore and aft, and the last 
molar is of more uniform width transversely. In both teeth the intermediate 
conical lobe, occupying the inner part of the crown, is proportionately more 
robust in M. frateimus. 

The depth of the jaw below the third molar is 2.6 lines; the breadth ol' 
each of the three back molars fore and aft is about eight-tenths of a line; the 
space occupied by the four molars is a little over 3 lines. 

SCIURAVUS. 

In the American Journal of Science for July, 1871, Professor ]\Iarsh has 
described an extinct genus of rodents from remains found at Grizzly Buttes, 
under the aboTe name, and refers them to two species with the names of 
Sciuravus nitidus and 8. undans. The former, described from an upper-jaw 
fragment with three molars, was about the size of the brown rat. The latter, 
indicated by a lower-jaw fragment with the incisors and the anterior three 
molars, was a somewhat larger animal. 

While we have not the means of determinmg whether Paramys is abso- 
lutely distinct from Sciuravus, we have the opportunity of examining a speci- 
men belonging to a different genus from the former, and which we suspect 
pertains to the latter. The specimen in question consists of a fragment of the 
left side of the lower jaw, containing the third molar, the alveolus behind, and 
part of that in front. It belonged to an animal but little larger than the rat. 
The fossil was found at Grizzly Buttes by Dr. Carter. The only remaining 
15 G 



114 

tooth it contains is represented in Fig. 30, Plate VI, magniticd eiglit diam- 
eters. 

The tootli is al)oiit a line in breadth, and, together with the alveolns back 
of it, occupies a space of 2^ lines. The crown of the tooth is quadrate, 
broader than wide, and is composed of tour principal conical lobes, as in the 
squirrels, and as in its associate Paramys The sculpture and connection of 
the lobes is difTerent, as may be conveniently observed by comparing Fig. 30 
with Fig. 27, representing a tooth of the same side of Paramys. It is espe- 
cially to be noticed that in the latter the back pair of lobes include, between 
them and the anterior lobes, a broad hollow, and the former are connected 
behind by an acute ridge, which forms the posterior border of the crown. 
The broad hollow of the latter is closed externally l:)y a festoon-like ridge 
connecting the outer lobes at their base. 

In the supposed tooth of Sciuravus (Fig. 30) the broad hollow of the crown 
so conspicuous in Paramys and Sciurus is not evident. The posterior lobes 
are conjoined by a transverse ridge, and are bounded behind by a thick ridge 
descending inwardly from the postero-external lobe. The transverse valley 
of the crown is occupied by a pair of ridges diverging from the postero- 
external lobe to those in advance. 

Order Carnivora. 

PATRIOFELIS. 

Pateiofelis ulta. 

A carnivorous animal, rather larger than our common American panther, 
and about the size of the jaguar, to wliicli the above name has been given, is 
indicated by remains in the Bridgcr Tertiary formation. The sijecimens 
from which it was originally described in the Proceedings of the Academy 
of Natural Sciences for March, 1870, were obtained near Fort Bridger, 
Wyoming, during Professor Hayden's exploration of 1869. They consist of 
portions of both rami of a lower jaw, unfortunately with most of the teeth 
lost or mutilated. The right ramus is represented, one-half the natural size, 
in Fig. 10, Plate II. 

The jaw of Patriofelis contains a series of five molar teeth immediately 
succeeding the canine tooth without conspicuous interval, as in some of the 
viverrine and musteline animals. The molar teeth arc all inserted Ijy a pair 
of fangs, and none of them appear to be of the jmrely tubercular kind. The 



115 

first of" the series is smallest, and the third the largest ; the i()urtli was inter- 
mediate ill size to the latter and the last one, which little exceeded tlie 
second. 

The crown of the last molar in the specimen appears as if it had been 
composed of an anterior pointed, or perhaps trenchant, lobe, and a large pos- 
terior heel. 

The crown of the penultimate molar appears to have been nearly of the 
same character. In the crown of the antepenultimate molar the posterior 
heel forms a median acute ridge from which the sides slope toward the 
bottom. The outer slope, nearly twice the depth of the inner, is bounded 
behind by a ridge descending from the summit of the heel. The inner slope 
is bordered by a basal ridge curving downward and forward from the summit. 

The canines, as indicated by portions of the alveoli, are large and powerful 
teeth, as in feline animals. The alveoli are about ^ i'lch in diameter. 

The jaw has nearly the same form as in the panther, but is proportionately 
shorter, and beneath the molar teeth of greater depth, in this respect resem- 
bling more the condition in the striped hyena. The condyle has the same 
form and relative position as in ordinary carnivora, but is thicker or of greater 
extent on its articular surface fore and afl than in the panther. Its compara- 
tive breadth is undeterminate, from its being broken at both ends in the 
specimen. 

The back portion of the jaw is proportionately narrower than in the 
panther; and the coronoid process, which appears to have had the same 
f(jrm as in this, is likewise narrower. The masseteric fossa is not so deep as 
ill ordinary carnivora. Extending from the coronoid downward, a little 
below the level of the condyle, it becomes, rather abruptly shallower, and 
from this position gradually lessens in depth toward the base, from which it 
is not abruptly defined by a narrow ridge, as in the ordinary carnivora. 

The symphysis is strong, and the rami approaching it thick, as in the 
pantlier. A group of seven mental foramina occupy a position at the side 
of the symphysis. The largest of them, as in the panther, is situated outside 
the back part of the canine alveolus. 

From the absence of the chai'acteristic portions of the teeth, the exact 
relationship of Patriofelis is not clear. It is perhaps intermediate to the 
feline and canine animals. 



116 
Measurements from the lower jaw of Patriofelis uUa are as follows : 

Inches. Lines. 

Estimatetl length of jaw 6 

Distance from back of condyle to canine alveolus 5 4 

Distance from back of condyle to back of last molar 2 3 

Space occupied by the molar series .3 

Breadth of coronoid at base 1 7 

Depth of jaw below penultimate molar -. 1 -i 

Depth of jaw below back of last molar 1 6 

Measurements of the molar teeth, estimated from their fangs and alveoli, 
are as follows : 

Lines. 

Breadth of first molar tooth 5 

Breadth of second molar tooth , 7 

Breadth of third molar tooth 8J 

Breadth of fourth molar tooth 7 

Breadtli of tifth molar tooth 8 

Fig. 20, Plate VII, represents a tooth discovered by Dr. Carter near Fort 
Bridger. It appears not to belong to the lower jaw of Patriofelis, but pci'- 
haps belongs to the upi)er jaw. The crown is composed of a large conical 
lobe with a broad heel, the sides of" which slope from a median ridge. The 
breadth of the crown is 8^ lines ; its thickness 5 lines. 

SINOPA. 

SiNOPA EAPAX. 

A lower-jaw fragment, containing two teeth and portions of two others, 
represented in Fig. 44, Plate VI, appears to indicate an extinct genus related 
to the canine family. The specimen was discovered by Dr. Carter in the 
vicinity of Fort Bridger, and was by him presented to the writer. It belonged 
to an animal about the size of the gray fox. 

The specimen is insufficient to ascertain with any certainty the exact rela- 
tionship of the animal to which it belonged, but the character of the teeth 
leads me to view it as having held an intermediate position to the existing 
genus Canis and the extinct one Hysenodon. 

Tlie teeth preserved entire in the specimen appear to correspond with the 
last premolar and the first or sectorial molar of the fox, and the remains of 
two teeth behind would be of the second and third molars. The last pre- 
molar is larger than the molars. Its crown is as wide, but is longer than that 
of the tooth retained behind it. The form of the crown is more like that in 



117 

Hyaenodoii (iiaii in th(3 fox. It is prnportioiiafcly longer and narrower than 
in the latter, and the accessory cnsp at llic back border of the principal oiie 
in the tijx is nearly obsolete in the fossil. The heel of the cro.wn is l)etler 
developed than in the fox. It forms a median acntc ridge, and slopes off on 
each side to the rounded base of the crown. 

The first molar, as liefore intimated, is smaller than the last premolar. It 
is as wide as the second molar, but not so thick, and is slightly wider than 
the last molar. It is proportionately better developed in its relation with the 
succeeding molars than in Hyasnodon. Its crown is intermediate in form 
and in the development of its parts to that in the fox on the one hand and the 
raccoon and badger on the other. The fore i)art of the crown, consisting of 
rather more than one-half, corresponds withthe sectorial ])orti()n of the same 
tooth in the fox, but accords more in shape and the relative position and de- 
velopment of its points with the homologous portion in the raccoon and bad- 
ger. The heel of the crown is bordered by a horseshoe-shaped ridge inclos- 
ing a cup-like concavity. 

The heel of the second molar, the only portion of the crown retained in 
the specimen, is stouter than in the first molar, liut has the same shape. The 
width of the crown is about equal to that of the tooth in advance, but has 
been slightly thicker. 

The last molar is a two-fanged tooth like those in advance, but is not quite 
so wide, and a small portion of the back of the crown indicates it to have 
been of less thickness. 

The base of the jaw-fragment is broken away in the spcchnen. The por- 
tion preserved presents nothing peculiar. 

Measurements of the fossil are as follows : 

Lines. 

Space occupied bj- the last premolar and molars 15 

Space occupied by the molars 11 

Breadth of crowu of last premolar 4 

Length of crown of last premolar at middle 3J 

Breadth of crown of first molar 4 

Length of crown of first molar at principal cusp 2i| 

Thickness of crown of first molar at heel 2 

Breadth of crowu of second molar 4 

Tliickuess of crown of second molar at heel 2^ 

Breadth of crown of last molar i! J 

The name Sinopa, applied to the extinct genus, according to Professor 
Ilayden, is aboriginal, and is applied by the Blackfeet Indians to a small fo.x 



118 

While the original notice of Sinopa rapax was in print, in the Proceedings 
of Ihe Academy of Natural Sciences of Philadelphia, Professor Marsh pul)- 
lished a description, in the American Journal of Science for 1871, of some 
remains of a carnivore from the vicinity of Fort Bridger, under the name of 
Vulpavus palustris. It is characterized from several upper molars which accord 
in size sufficiently to pertain to the same animal as that above described. 
Further researches may prove the two animals to be the same. 

Sinopa eximia. 

A jaw-fragment, discovered by Dr. Carter at Grizzly Buttes, and repre- 
sented in Fig. 45, Plate VI, belongs to a smaller carnivore than the preced- 
ing. It was probably allied to the former, and may perhaps pertain to a 
smaller species of the same genus, of which I have some doul)t, though, in 
the absence of more confirmatory evidence, I have considered it as such. 

The specimen contains two teeth, which sufficiently resemble those re- 
tained in the jaw-fragment referred to Sinopa rapax, as to render it probable 
they are the corresponding ones, though the contiguity of the symphysis leads 
me to suspect that they may be the last two premolars. As seen in the 
figure, the back of the symphysis is just below the position in advance of 
the first tooth of the specimen. The teeth in shape are nearly like those in 
Sinopa rapax, but the proportions are reversed. The crowns of the two 
teeth have the same length, but the hinder one is wider and thicker. 

The measurements of the specimen are as follows : 

Lines. 

Depth of the jaw below the teeth 4| 

Space occupied by the two teeth 4J 

Width of the crown of the first tooth 2 

Length of the crown of the first tooth 2:^ 

Width of the crown of the second tooth 2J 

Length of the crown of the second tooth 2^ 

UINTACYON. 

UlNTACYON EDAX. 

An interesting fossil, recently received from Dr. Carter and discovered by 
him in the Bridger beds, consists of the greater portion of the right ramus of 
a lower jaw, represented in Fig. 6, Plate XXVII. The specimen indicates 
a carnivorous animal, probably marsupial, and of a hillierto unknown genns, 
for which the above name has been proposed. 



119 

The jaw contained a series of eight inohir teeth and a canine separaled 
I'rom the former by a small hiatus. Of the molar teeth, the specimen retains 
))art of the first molar and the succeeding molar, represented in Figs. 7, H, 
and the intermediate three premolars represented in Figs. 9, 10. 

The jaw-fragment agrees in its form and proportions with the correspond- 
ing part in the existing fox. The teeth also, so far as they are preserved, are 
nearly like those of the latter animal. 

The canine tooth was equally well developed as in the latter, and the first 
premolar is inserted by a single fang. The second premolar likewise resem- 
bles the corresponding tooth of the fox. 

The third premolar is peculiar, and perhaps anomalous. It resembles niore 
the form of an upper pi'emolar than the nsual form of lower premolars. It 
has three fangs, of which two are inserted in a line with those of the con- 
tiguous teeth, while the third fimg is external. The crown is a four-sided 
pyramid with projecting basal angles, of which the postero-internal one is the 
most prominent. 

The fourth premolar is like the last one of the fox, Ijut is proportionately 
thicker. The fifth premolar is lost, and, like the preceding tooth, was inserted 
Ijy a pair of fangs. 

The first molar has lost the fore part of its crown, and this appears not to 
have been proportionately so well developed as in the fox. The crown of 
the second molar is nearly of the same form as in the latter. 

The last molar is a small tooth, as in the fox, and is also inserted by a single 
fang. 

The measurements of the specimen are as follows : 

Lines. 

Depth of lower jaw at second premolar 4. 8 

Depth of lower jaw at first molar 4. .S 

Distance from fore part of caniue to back of last molar IS. 

Length of the molar series 14. 8 

Length of the premolar series 8. 8 

Length of the true molar series (J. 

Breadth of second premolar 1-7 

Breadth of third premolar 1-5 

Breadth of the fourth premolar 1- *• 

Breadth of the fifth premolar ^-4 

Breadth of the first molar >5. ^ 

Breadth of .second molar ^- " 

Breadth of third molar t • " 

The main peculiarity of tlie fossil is the presence of an eighth tooth to the 



120 

molar series. The one in excess ul' the usual nunil)er, witliuiit other considera- 
tion tlian convenience, I have viewed as a premolar. From its anomalous, or at 
least unusual, torni, the tburth of the series of the premolars may l»e regarded 
as the additional tooth. Without it, the jaw would indicate a small canine 
animal, or at least a species of a closely allied genus. The animal was al)out 
half the size of the common fox. 

UlNTACYON VORAX. 

Perhaps a larger .species of the genus just named is indicated by the jaw- 
fragment represented in Fig. 11, Plate XXVII. The specimen was obtained 
on Henry's Fork of Green River, during Professor Hayden's expedition of 
1870. 

The jaw-fragment agrees in form with the corresponding part of the jaw- 
specimen of U. edax, but from its proportions belonged to an animal twice the 
size. It contains the penultimate molar, the heel of the one in advance, and 
the alveolus of the last molar. The teeth agree in their proportions witli 
those of U. eda.r, and the penultimate molar, represented in Figs. 12, 13, 
sufficiently resembles that of the latter to belong to the same genus. The 
l>ri-atllh of the penultimate molar is 2|- lines. 

Order Tnsecfirora. 

OMOMYS. 

Omomys Caeteri. 

The first mammalian fossil described from the Bridger Tertiary beds con- 
sists of the fragment of a lower jaw with teeth, discovered by Dr. Carter on 
Twin Butte, about one mile from Fort Bridger. The specimen is repre- 
sented in Figs. 13, 14, Plate XXIX, of ''The Extinct Mammalian P'auna 
of Dakota and Nebraska," published as the seventh volume of the Journal of 
the Academy of Natural Sciences of Philadelphia tor 18G9, and is described 
on page 408 of that work. 

The jaw-specimen was accompanied with tVagments of the cranium, for the 
most part too much broken to determine anything from them. They would 
appear to indicate a skull about the size of that of the common weasel, but 
with weaker jaws. 

A fragment of the cranium retains a straight linear sagittal crest al)out 14 



121 

lines in lenglli to its l)il'iircatioii at \\\r lorcliead. 'riic loinpural siirfacps 
appear to be full and convex, as in the weasel. 

An occipital condyle resembles those of the latter, and measures about 1 
lines in its longer diameter. 

The ramus of the lower jaw, compared with that of the weasel, is more 
slender and delicate in its proportions. In the specimen both extremities 
are broken, but a portion of the sym])hysis is still retained. 

The jaw below the molars is of nearly uniform depth, and measures about 
2 lines. The base is slightly convex fore and aft, but makes a concave turn 
toward the angle. The masseteric fossa below is well marked. A small 
mental foramen occupies a position below the antepenultimate premolar. 

In the earlier description of the specimen, I remarked that seven molar 
teeth, in an unbroken series, appear to have occupied the side of the jaw. In 
the actual condition of the fossil there are four teeth, consisting of the anterior 
two molars and the two premolars in advance. In front of these there are 
two empty sockets and parts of two others, and behind them there are the 
imperfect alveoli for a third molar. The sockets at the front of the jaw I at 
first supposed were intended for two additional two-fanged premolars. They 
fill up the interval between the retained teeth and the edge of the symphysis 
so closely that, from this fact and their relative size, I now suspect that they 
may have been occupied by a single-fanged premolar, a small canine, and 
two incisors. Assuming that such was the case, without any certainty in the 
matter, the number of molar teeth in the series would be six, of which three 
were premolars and three true molars. In this view the teeth retained in 
the specimen consist of the second and third premolars and the first and sec- 
ond molars. Their constitution would appear to indicate an insectivorous 
animal which, jjerhaps, was marsupial in character. 

The teeth successively decrease in i)rominence or height from the second 
premolar to the second molar. They resemble in constitution the corre- 
sponding teeth of the opossum. 

The crown of the premolars is laterally compressed conical, thicker behind 
than in front, and is embraced by a basal ridge. The crown of the second 
premolar, more prominent than in any of the other teeth, is triangular, longer 
than broad, and sharp-pointed. Its anterior slope is slightly convex and acute; 
its posterior slope is longer, slightly concave, and wide. The basal ridge 
ibrms an excavated heel behind, a more elevated ledge in front, and a jiair of 
IG G 



122 

t'estooiiR both intcrnall}' and extemall\'. The inner side of the crown is 
defined from the back border by an acute ridge. 

The crown of the last; premolar has the same constructioii as that in advance, 
but is sliorter and wider. The heel is slightly wider and more excavated, but 
the fore part of the basal ridge is not so prominent. The ridge defining the 
inner side from the posterior border is slightly more advanced and prominent, 
and the surfaces it separates are more concave. 

The crowns of the true molars are nearly alike in form and size, though 
the first is in a trifling degree more prominent and wider. They have the 
same general constitution as those of shrews, of the hedgehog, the galeopi- 
thecus, and the opossum. Eacli is composed of two divisions, of which the 
posterior is the larger. The anterior division consists of a small, outer demi- 
conoidal lobe, with aV-like summit joining by its arms a pair of inner and smaller 
pyramidal lobes. The posterior division consists of an outer lol)e like that in 
advance, but larger, and joining it by one of the arms of its V-like summit, 
while the other arm joins a small pyramidal lobe at the inner corner of the 
crown. The outer part of the base of the crown is embraced by a basal cin- 
gulnm nearly half its depth. 

The space occupied 1))^ the teeth, in the view that there were two incisors, 
a canine, and six molars, is 74- lines. The last two premolars and the suc- 
ceeding two molars occupy a space of 4.6 lines. 

PALiEACODON. 

Pal^acodon veeus. 

Two small fossil specimens, discovered the previous, summer by Dr. Carter 
at Lodge-Pole Trail, Wyoming, indicate an insectivorous animal, or, perhaps, 
a marsupial allied to the opossum. One of the specimens consists of an 
nppcr-jaw fragment containing a molar, which appears to be the penultimate 
one of the series; the other is an isolated tooth, perhaps the last upper pre- 
molar or first molar. 

The jaw-fragment is the portion which forms the anterior abutment of the 
zygoma. In advance of the tooth it retains are the remains of the alveoli of 
two others, and behind it the remains of another. 

Tlie molar of the jaw-fragment is represented in Fig. 46, Plate VI, magni- 
fied four diameters. The crown bears some resemblance with that of the 
molars of tiic opossum, ])ut is less narrowed internally, and is therefore more 



123 

(iu;iilr;iie or le.s.s triangular in tbrin. Tlie conslitiiiiou is similar, but, Uk^ oiilnr 
lobes are proportionately better developed and the median ones are mticli 
lediiced in size. A basal ridge nearly embraces the crown, ])ut is nearly 
obsolete internally, and is best developed posteriorly, where it forms a wide 
festoon. 

The isolated tooth is a diminished representative of the one in the jaw- 
fragment, and probably held the position of the third in advance of it. It 
may, perhaps, represent a smaller species. The specimens indicate an animal 
l)ut little more than half the size of the ©possum. How it is related with 
Omomys the paucity of material prevents a positive determination. The size 
of the teeth indicates a larger animal than Omomys Carteri. 

In the American Journal of Science for 1871, Professor Marsh has 
described a tooth, from Grizzly Buttes, which he likens to the premolars of 
some insectivora, and refers it to a species with the name of Triacodon fallax. 

He remarks that the species was probably about two-thirds of the size of 
the opossum, which dimensions would be too great for the animal we have 
named Palceacoclon verus. 

The sizes of the teeth referred to the latter are as follows: 

Lines. 

Space occupied by tlie penultimate and antepenultimate molars 4 

Breadth of penultimate molar 2 

Width of penultimate molar 2^ 

Breadth of last premolar li 

Width of last premolar 1 ^ 

WASHAKIUS. 

Washakius insignis. 

A jaw-fragment of a small animal recently sent to me by Dr. Carter is rep- 
resented in Fig. 3, Plate XXVII, magnified three diameters. The specimen 
was found in the Bridger beds by a Shoshone Indian and given to Dr. Carter. 
It is quite different in appearance from any similar fossil from the same for- 
mation submitted to my inspection, and appears to indicate a different genus 
from those described in the preceding pages. I am uncertain as to its ordi- 
nal affinities, but suspect it to have pertained to an insectivorous animal, per- 
haps one of the many which have been indicated by Professor Marsh from tbssils 
of the Bridger beds. 

The jaw-fragment contains the last two molars, the triturating surfiices of 



124 

which, considerably worn, are represented in Fig. 4, Plate XXVIT, magnitied 
eight diameters. 

The portion of jaw is of moderate depth and stont in proportion. The 
base is thick and rounded. The masseteric depression is well marked, and is 
defined at its lower part in front by a strong ridge descending from the fore 
part of the coronoid process and ending in a conspicnous angular tubercle. 

The {eeth resemble most nearly tliose of Microsyops. They are inserted 
with a pair of flings; but in the last molar the posterior fang is a connate pair 
extended backward. 

The crown of the antepenultimate molar is quadrate with rounded corners, 
and is composed of four lobes. The postero-external lobe is largest, and is 
crescentoid conical. The postero-internal lobe is smallest and conical, and is 
joined at the summit by the back arm of the postero-external lobe. The 
anterior pair of lobes are connate, and are joined about their middle by the 
fore arm of the postero-external lobe. A deep angular valley occupies the 
inner part of the crown between the anterior and postero-internal lobes, and 
bounded externally by the postero-external lobe. A basal ridge incloses the 
outer part of the crown, but is interrupted in the most prominent part of the 
postero-external lobe. 

The crown of the last molar, at its anterior two divisions, is composed on 
the same plan as that of the molar in advance, but it is prolonged backward 
so as to form an additional lobe. 

The measurements of the specimen are as follows: 

Lines. 

Dei)tli of lower jaw below tlie last molar 2.1 

Space occupied by the last two molars '. 2. 4 

Breadth of second molar 1.2 

Breadth of last molar . . ^ 1. 4 

The genus I have named in commemoration of Washakie, chief of the 
Shoshone Indians, with whom I had the pleasure of meeting during my visit 
to Fort Bridger. He has always been distinguished for his high characler, 
and for his friendliness to the white race. 

ELOTHERIUM. 

In tlie American Journal of Science of 1871 Professor Marsli has described 
a molar tooth, from Hejiry's Fork of Green River, which he attributes to a 
suilline pacliyderm with the name of Elotherium lentus. The specimen, he 



- - 125 

observes, indicates a species about half tlic size of E. Morfoni, tlie reiuaius 
of wiiicli are found in the Miocene Tertiary deposit of (he Mauvaises Terres 
of White River, Dakota. 

Among the colh^ctions of fossils from the Bridger beds I have seen no 
remains which could be ascertained to belong to this genus. Figs. 28 and 
29, Plate VII, represent two views of an incisor tooth which looks as if it 
might pertain to E. Morto)ii. The specimen was found by Mr. Pierce, ol" 
Denver, twenty miles southeast of Cheyenne City, Wyoming. 

REPTILIA. 

The Bridger Tertiary formation, in comparison with the earlier Tertiaries 
of White Eiver, Dakota, and of the Niobrara River, Nebraska, is remarkable 
for the variety as well as the number of its reptilian remains. Amid the 
multitude of fossils which Rave been collected in the latter localities nearly 
all belong to mammals; and though the remains of turtles are abundant, they 
appear all to be referable at most to a single species for each locality. No 
fragment of a crocodilian, lacertian, or serpent has yet been discovered either 
in the Mauvaises Terres of White River, Dakota, nor in the sands of the 
Niobrara River, Nebraska. From the Bridger beds there have been col- 
lected many remains of different species of crocodiles, turtles, lacertians, and 
serpents. 

Order Crocodilia. 

Body lizard-like in form, with four short limbs and feet, and a long, 
powerful tail. With long jaws, provided with a single row of teeth inserted 
in distinct sockets. Skin protected by bony plates. 

CROCODILUS. 

The Bridger Tertiary formation contains numerous remains of crocodiles. 
Many collected by Professor Hayden's party in 1870, and olhcrs obtained by 
Drs. Corson and Carter during the same and the succeeding year, have been 
submitted to the inspection of the writer. The specimens were found in 
various localities in the vicinity of Fort Bridger, as Little Sandy River, Big 
Sandy River, Green River, Black's Fork of the same, Church Buttes, Grizzly 
Buttes, &c. The specimens examined indicate several species, though from 
their generally detached and imperfect condition we have not been able to 
collocate them so as distinctly and clearly to establish the species. Some of 



126 

the specimens we have referred to two named species. Professor Marsh 
subsequently named five species from remains obtained in the same locali- 
ties during his exploration of 1870. Professor Cope has more recently named 
four additional species. It is probable that when the fossils are more care- 
fully studied, the number of sjjecies to which they have been referred will 
be reduced. 

Crocodilus aptus. 

This species was originally named in 1869 from a fossil preserved in the 
Greological Cabinet of tlie General Land-Office in Washington. The speci- 
men was obtained by Colonel John H. Knight, United States Army, near 
South Bitter Creek, Wyoming. Though consisting of a detached vertebra, it 
especially attracted my attention from having previously seen no remains of 
crocodiles in the large collections of fossils from the Tertiary formations of the 
west. 

The vertebra represented in Fig. 2, Plate VIII, belongs to the cervical 
series, and resembles, botli in size and form, the sixth or seventh of the Mis- 
sissippi alligator. The bone appears to have been of mature age, and seems 
thoroughly petrified. It has lost the greater part of its neural arch and 
dependent processes, but is otherwise well preserved. From portions of 
adherent matrix, it has been imbedded in arsofl rock similar to that adherent 
to some of the bones from other localities above mentioned. 

The body of the bone in its axis is 16 lines long; its height and breadth 
in front are 14 lines. The hypopophysis, directed obliquely downward and 
forward, as in the alligator, is about 5 lines long. Back of the process the 
Ijody is less prominently carinated than in the latter animal. 

Crocodilus Elltotti. 

The species thus named was originally designated from a specimen 
obtained, during Professor Hay den's exploration of 1870, at the junction 
of the Big Sandy and Green Rivers. It consists of an upper-jaw fragment 
containing two teeth and portions of two others, and is represented in Fig. 4, 
Plate VIII. It appears to be the anterior portion of the left maxillary, con- 
taining the fourth and fifth maxillary teeth and the fangs of the two succeed- 
ing ones. The shape of the jaw-fragment is nearly like that of the corre- 
sponding portion of the upper jaw in the mugger {Crocodilus paluslris) of 
India, but is more rugose on its exterior surface, and the palatine surface is 



127 

more vaulted. The teetli retained in the specimen have tlieir crowns only 
partially protruded. Tiiey are proportionately more robust, or shorter and 
less pointed, than in the mugger. Strong ridges define the inner from the 
outer surfaces of the crown, which exhibits no indication of fluting, but the 
enamel is finely and closely wrinkled longitudinally. 

The space occupied by the teeth, from the fourth to the seventh inclusive, 
is 35 lines. The entire length of the fifth or largest maxillary tooth is esti- 
mated at about 2^ inches. The protruded portion measures externally ^ of 
an inch in length, and its diameter at base fore and aft is 7J lines, and trans- 
versely GJ lines. 

Fig. 6, Plate VIII, represents a large portion of the upper part of a skull, 
which has been attributed, but with no certainty, to the same species as the 
foregoing. The specimen, in a number of scattered fragments without teeth, 
was discovered, by Henry W. Elliott, on Little Sandy River, during Pro- 
fessor Hayden's exploraticni of 1870. 

The fossil indicates a form of skull very difierent from that of our alligator, 
and is that of a true crocodile. It approached in form more tiiat of the mugger of 
India or of the Nile crocodile than that of the American crocodile, (C ameri- 
canus.) 

The cranium above is remarkably flat ; from its lateral borders defined by 
the squamosals and post-frontals, and from the occipital border to the face in 
advance of the orbits, it forms a nearly uniform plane with no depression of 
the forehead nor eversion of the orbital margins. This uniform flatness is 
also extended along the middle of the face to the muzzle. This and the 
alveolar borders of the face are about as convex as in the mugger. 

The sides of the muzzle are deeply notched at the conjunction of the pre- 
maxillaries and maxillaries, and the bottom of the notch exhibits a conspicu- 
ous recess for the accommodation of the large canine-like tooth of the man- 
dible. A second and less conspicuous notch, as usual in the true crocodiles, 
occupies a position about the middle of the maxillaries. 

The lateral boi'ders of the cranium are less angular or more rounded 
approaching the orbits than in the mugger and the American crocodile. 
The superior temporal orifices are subrotund and nearly as wide transversely 
as fore and aft. The intervening parietal surface is broad and deeply 
l)itted. The temporal surfaces of the parietal form a pair of deeply concave 
recesses. 



128 

The anterior orl^ital Ijorder, as constituted by tlie prefrontals and lachry- 
mals, is depressed or slopes inwardly toward the orbits. 

The nasal process of the frontal is niucli prolonged, extending 2 inches 
in advance of the position of the ant-orbital margins. The prefrontals are 
proportionately long and narrow compared with those in the mugger. Their 
length is about 4 inches ; tlieir breadth, where widest, is 14 lines. 

The nasals are broad and flat at the back part. They are proportionately 
of greater breadth than in the mugger. Their estimated length is 9i inches; 
their breadth together in advance of the lachrymals is about 2J inches. 

The fore part of the face, or the muzzle, has the same form as in the mugger 
and other true crocodiles, but is proportionately less thick than in the one 
specifically mentioned. The nasal orifice holds a more advanced position 
than usual, so that the alveolar border in front is barely more than half the 
extent it is in the mugger, nor is it perforated as in the latter and other true 
crocodiles. The upper surface of the skull is everywhere exceedingly rugose, 
with reticular ridges inclosing deep pits, and in some positions is deeply 
scored by vascular gi'ooves. 

Four teeth occupied the sides of the premaxillaries, forming an unbroken 
row. The intermediate pair are the larger and of nearly equal size ; the 
others are also nearly of equal size. The tirst tooth did not occupy the fore 
part of the premaxillary as usual, in the true crocodiles, but is over an inch 
from the position of the symphysis, close to the second tooth. A large recess 
occupies the fore part of the palatine surface of the premaxillary, for the 
accommodation of the first mandibular tooth, as usual in the crocodiles, but it 
is closed or does not communicate by a perforation with the upper surface of 
the premaxillary border. The recess holds a position internal to the first pre- 
maxillary tooth. Smaller conical recesses occupy the intervals internally of 
the succeeding three teeth. 

The maxillary appears to have accommodated fourteen or fifteen teeth, of 
which the fifth one was the largest, as in other crocodiles. The fourth, in 
comparison with the fifth one, .was proportionately larger than in the mugger, 
and the sixth was not much less in size. 

The depth of the socket of the fifth maxillary tooth is full 2 inches ; its 
fore and aft diameter about f inch. The depth of the fourth socket is 20 
lines : its diameter 8 lines. 

The premaxillary teeth, in comparison w ith those of the mugger, appear to 



129 

have l)cen proportionately about as large. The anterior scries of maxillary 
teeth were rather larger, and the posterior series smaller. 

Detached portions of both quadrates accompany the other portions of the 
skull. They are somewhat peculiar in several anatomical points. The an- 
terior surface is unequally divided by a conspicuous ridge, descending to 
within an inch of the articular surface for the mandil:)le. The grooved or 
trochlear condition of the latter surface is much more decided than in the 
mugger or the American crocodile. 

Measurements taken from the specimen above described are as follows : 

luclics. 

Length from occipital border to end of muzzle • 20 

Breadth of cranium at occipital border between prominent angles of .squamosals. 7 

Breadth of cranium at postorbital angles 51 

Breadth of cranium between temporal orifices . . 1 

Breadth of forehead between orbits I.1 

Breadth of temi)oral orifices 1.^ 

Fore and aft diameter of the same 1^ 

Leugth of parietal 2;^ 

Length of frontal 5.1 

Bi'eadth of frontal where it joins the post-frontals 2,^^ 

Fore and aft diameter of the orbits 2-^ 

Length of face in advance of the orbits i:j.i 

Breadth of face outside the fifth maxillary teeth (ja 

Breadth of muzzle as formed by premaxillaries 5 

Breadth of muzzle at notch back of the latter 4 

Leugth of i>remaxillaries G 

Breadth of nasal orifice , 2A 

Fore and aft diameter of the same 2.^ 

Thickness of premaxillaries in advance of the same ^ 

Estimated length of entire alveolar border 14^ 

Space occupied by the anterior five maxillary teeth 3f 

Space occupied by the posterior five maxillary teeth 3 

Breadth of articular surface of quadrate for the mandible 2^ 

A detached basi-occipital, obtained near Little Sandy River, may, perhaps, 
belong to the same species as the preceding. The occipital condyle has 
nearly as great a vertical as a transverse diameter, the former measuring 15 
lines, the latter 17 lines. 

The last summer Dr. Joseph K. Corson sent, as a gift to the museum of the 
Academy of Natural Sciences of Philadelphia, a specimen consisting nearly 
of the whole of the lower jaw of a large crocodile. He discovered the fossil 
imbedded in a green sandstone in the vicinity of Fort Bridger. In removing 

it from its matrix it was much broken, and most of the teeth were destroyed. 
17 G 



loO 

The left ramus in a restored condition is represented in Fig. 8, Plate VIII, 
one-half the natural size. 

The lower jaw belonged to a larger animal than the cranial specimen from 
Little Sandy River, and probably pertained to a different species. The form 
of the jaw is nuich like that of the mugger, but is of more robust proportionss 
The rami, in their dentary portions, are much thicker in proportion to their 
depth, and the symphysis is of greater extent, in this respect presenting a 
greater resemblance to the condition iu the American crocodile. 

The dentary portions of the rami the greater part of their length are as 
thick and thicker than the depth. Half way between the symphysis and the 
median enlargement of the dentary portion of the ramus the thickness is over 
2 inches, while the depth is ^ of an inch less. In the position of the enlarge- 
ment just mentioned, the thickness is 2 inches and 2 lines, while the depth 
is only 2 lines moi'c. The symphysis has measured about 44' inches fore and 
aft, and liut slightly more than this transversely opposite the position of the 
large canine-like teeth. 

The splenial bone, as if to give greater strength to tlie ponderous jaw, 
extends close up to the symphysis. The outer portion of the jaw in the posi- 
tion occupied by the teeth, is more rounded than in the mugger. The back 
portion of the jaw in form and constitution appears to agree with that in the 
mugger. The outer surfi\ce of the jaw, strongly ll)veated back of the hu-ge 
oval foramen, presents the usual vascular grooved and perforated appearance 
in advance. 

AI)out eighteen teetli occupied each ramus of the jaw, but all are broken 
from the specimen except one. Some of the broken and detached teeth 
accompany the jaw. They appear to have been comparatively robust, short, 
and blunt, conical in form, and but feebly curved. The enameled crown is 
rugose and longitudinally grooved, but not properly fluted; the narrow grooves 
separating wider convex and rugose longitudinal ridges. They sufficiently 
differ from those in the jaw-specimen referred to Crocodilus Eltlotti to per- 
tain to a different species. 

The end of the symphysis of the jaw ov of the chin is l)rokcn away, so that 
nothing can be ascertained in regard fo the first pair of teeth of the two 
i-ami. A lai'ge tooth, canine-like in its relative position and size, as usual in 
the crocodiles, was nund^er t()nr in the series. Tlie sof^kct, occupied by 
green-sand matrix, is about 10 lines in diameter. The expansion of the sym- 



131 

[ihysLs in the position of this socket indicates its caniiic-likc leelh to have 
been accoaimodatcd when at rest iu a recess of the upper jaw at the junction 
of the premaxillarics and inaxiikiries. 

Succeeding the canine tooth alveolus, there are the remains and sockets oi" 
five comparatively small teeth. Then followed several ol' the largest teeth 
accommodated by the second expansion of the jaw. The socket for the 
eleventh tooth is about the size of that of the canine tooth. In the left ramus 
it retains the tooth, the apex of which alone had protruded. After tliis tooth 
there followed a series of five others which successively decreased in size. 

Measurements of the lower jaw are as follows : 

Incbes. Lines. 

LeDgth of rami of lower jaw 20 G 

Width of lower jaw outside the glcuoid articn]ation.s 12 

Width of lower jaw a short distaace in front of the glenoid articulatious.. 13 

Greatest width of symphysis 4 o 

Width of jaw at second enlargement, below the eleventh tooth (J 

Depth of jaw at oval foramen 3 10 

Depth of last tooth 2 8 

Depth of eleventh tooth 2 4 

Thickness below the eleventh tooth , 2 2 

Depth of ramus near symphysis 1 !) 

Thickness of ramus near symphysis 2 2 

Extent of symphysis fore and aft 4. 3 

Breadth of glenoid articulation 2 7 

Length of hook-like process back of glenoid articulation 2 5 

Space occupied by the teeth 11 

Length of oval foramen 2 8 

W^idth of oval foramen .' 11 

Fig. 1, Plate VIII, represents the body apparently of a first Inml^ar verte- 
bra; and Fig. 5 of the same plate, the proximal extremity of a left femur, 
large enough to belong to the same animal as the cranium above described. 



rp 



The two specimens were found together by Professor Hayden's party near 
Little Sandy Eiver. They present no decided peculiarity distinguishing them 
from the corresponding part in the living crocodiles. The shaft of the femur 
contains a medullary cavity larger than usual in the latter, and in the specimen 
it is filled with chalcedony. 

The measurements of the specimens are as follows: 

Line.s. 

Length of body of first lumbar vertebra beneath 20 

Depth of body anteriorly 18 

Width of body anteriorly ' 18 

Width of head of the femur 20 

Diameter of shaft below the inner process 12^ 



132 

Fig. 3, Plate VIII, represents a specimen of a first caudal vertebra of a 
smaller species of crocodile than those indicated by the preceding specimens. 
It was obtained by Professor Hayden's party near Little Sandy River. The 
length of the body with its double ball is 21J lines. Several other vertebra? 
from Black's Fork of Green River, and from near Church Buttes, Wyoming, 
from their size and conformation, would appear to belong to the same species. 

Order Chelonia 

No other Tertiary deposit in North America has yielded such an abun- 
dance of remains of different species and genera of turtles as the Bridger beds. 
The fossils represent a large proportion of fresh-water and paludal forms ; the 
others pertain to land tortoises. Fragments of turtle-shells are the most fre- 
quent of the vertebrate fossils met with, strewed on the bare tops and sides of 
the buttes or among the debris at their base. Entire shells are comparatively 
rare, and if they have been complete as fossils, they soon undergo disintegra- 
tion after exposure on the Inittes. Most of them have been much crushed, 
while embedded, under pressure of the superincumbent strata, and now when 
exposed from the softening of the matrix they readily fall to pieces. 

The greater quantity of the turtle remains are referable to a species of fresh- 
water terrapin of the genus Emys, the shells of which present sufficient variety 
as to have at first misled me in referring them to several different species. 
The next most abundant remains are those of one or two species of soft-shelled 
turtles of the genus Triouyx, and after these the remains of a large land-tor- 
toise. Besides the species and genera described in the succeeding pages. 
Professor Cope has recently indicated a number of others from the same for- 
mation. 

TESTUDO. 
Testudo Corsoni. 

Among the many remains of turtles from the Bridger Tertiary beds are 
those a^jparently of a large land-tortoise. Small and for the most part un- 
characteristic fragments of the shell were obtained by Dr. Carter in 1869 
and during Professor Hayden's exploration of 1870, but it was not until I 
received the specimen represented in Fig. 7, Plate XV, that I recognized the 
character of the species to which they pertained. 

The last-mentioned specimen was discovered by Dr. Corson at Grizzly 



133 

BiiJtes. It consists of the anterior extremity oftlie under shield or ])Iastron, 
consisting of the fore part of the episternals and the end of the entosternal. 
The specimen might l)e supposed to belong to an Emys, but its resemblance 
in form with the corresponding part in living species of Testudo leads me to 
place it with this genus. The episternals project together rather abruptly 
into a long, thick, and broad spade-like process, nearly straight at the front 
border, but slightly notched at the middle. The projection behind is defined 
by the outer extremities of deep grooves defining the gular and humeral scute 
impressions. Its lower surface is strongly convex ; the upper surface slopes 
forward to the acute border of the process. 

Back of the gular surface above, the plastron is deeply concave, but is not 
excavated beneath the former as in the gopher, {Testudo Carolina.) 

The end of the entosternal plate is impressed l>y the contiguous ends of the 
gular scutes. The episternal process is about 2 inches long ; its breadth at 
base is 5^ inches. The extremity of the process is 3| inches in width. The 
thickest part of the episterna measures IJ inch. 

The species I have named in honor of its discoverer. Dr. Joseph K. Corson, 
United States Army, who to a love of his profession adds a special interest 
in the promotion of the natural sciences. 

During my recent trip to Fort Bridger I was so fortunate as to obtain a 
number of additional specimens referable to Testudo Corsoni. Some of them 
had been previously collected I)y Drs. Corson and Carter, and others were 
found during our explorations of the battes near Fort Bridger, and those of 
Dry Creek ten miles from the former. 

One of the best preserved specimens consists of a nearly complete ventral 
shield or plastron, represented in Fig. 2, Plate XXX. This was discovered 
by Dr. Corson at Grizzly Buttes, and presented by him to the Academy. In 
the complete condition it has measured upward of 2 feet in length, and is 
estimated to have been about IG inches in breadth to its sutural conjunction 
with the upper shell. 

In its form and propoi'tions it resembles that of the living Testudo radJala 
of Madagascar more than it does that of the great Galapagos tortoise. 
. The lobes of the plastron are of nearly equal length and breadth. The 
prolonged extremity or spade-like process of the anterior lobe is lost in the 
specimen. The posterior lobe terminates in a deep, wide, angular notch 
included by two angular processes. 

The fore part of the anterior lobe is slightly bent ujiward and nearly straight 



134 

transversely. The plastron Iroui the position of the pectoral scute impres- 
sion l)ackwar(l becomes gradually and deeply concave. The deeper part of 
.the concavity is defined on the posterior lobe of the plastron by a narrow flat 
ledge laterally, which widens behind on the angular processes terminating the 
plastron. The sternal bridges are moderately convex, and are wide fore and 
aft. 

The anatomical structure of the osseous plastron and the relative position 
and number of its scutes are the same as in modern species of Testudo. 

The entosternal bone is subpyriform and wider than long. Its fore extrem- 
ity reaches just in advance of the ends of the gular scute impressions, and its 
back border reaches the groove defining the humeral and pectoral scute 
impressions. 

All the grooves defining the scute impressions are well marked, being deep 
and wide. The proportions of the scute impressions are nearly the same as 
in recent testudines. 

The pectoral scute impression is longer at both extremities than interme- 
diately. The groove defining it in front, commencing externally just in 
advance of the bottom of the axilla, curves backward and inward, and then 
turns forward and inward to the position of the back suture of the entosternal 
plate. 

The measurements of the specimen are as follows : 

Inches. 

Estimated length iu median line to bottom of poststerual uotcli 24 

Estimated leugtli on each side to ends of poststerual processes 20^ 

Estimated width 2o" 

Estimated length of anterior lobe of plastron in median line 8 

Length of posterior lobe of plastron iu median line 5 

Length of posterior lobe of plastron laterally 7 

Width of anterior lobe at bottom of axilla; 12 

Width of posterior lobe at bottom of inguinal fossa; 13 

Width at bottom of anterior prolongation of i^lastrou 5 

Width at ends of poststerual angular processes 7i 

Depth of ijoststernal notch 2J 

Width fore and aft of sternal bridge 9^ 

Length of entosternal plate 4J 

Width of entosternal plate 5^ 

Length of hyosternal plate in median line (i^ 

Length of hyposternal plate iu median line 5^ 

Length of xiphisternal plate in median line 4^ 

Length of pectoral scute impressions iu median line , 1^ 

Length of i)ectoral scute impressions where narrowest 1 

Length of abdominal scute impressions iu median line 9 

Length of femoral scute impressions in median line 3j 



135 

Inebes. 

Length of caudal scuto impressions in median line 2^ 

Tliickuess of plastron at base of anterior prolongation liJ 

Thickness of anterior lobe laterally near bottom of axilla 1 

Thickness of posterior lobe near bottom of inguinal fossa 1^ 

Thickness of plastron near the center iJ 

During a day's excursion to Dry Creek Buttes, ten miles from Fort Bridger, 
Mrs. Anna Carter, the wife of Dr. Carter, who accompanied us, discovered a 
large turtle jiartially imbedded in a green sandstone on the top of a butte. 
The upper shield had been destroyed by recent exposure, but the nearly com- 
plete plastron was obtained by removing the cast of the shell above it. The 
sutural connections of the bones are somewhat obscured by the firm adhei'ence 
of particles of sand. It retains the anterior spade-like process nearly entire, 
and this is represented in Fig. 4, Plate XXX. 

The specimen presents some differences from the former, which, however, 
I have not regarded as specific, though they may be so. The spade-like pro- 
longation of the plastron is more abrupt and considerably longer than in the 
fragment upon which the species was originally founded. The fore part of 
the anterior lobe of the plastron approaching the lateral border along the 
groove defining the gular and humeral scute impressions is much more convex 
than in either of the preceding specimens. From the position of the entoster- 
num backward, the plastron becomes concave, as in the former specimen, but 
the concavity is comparatively shallow. The poststernal notch is also of less 
depth than in the previous specimen, but otherwise the plastron is sufficiently 
like the latter to pertain to the same species. 

The measurements of the specimen are as follows : 

Inches. 

Length of plastron in median line ^5 

Length of plastron on each side 2Gi 

Width of plastron at middle, estimated at about 20 

Length of anterior lobe 9 

Length of posterior lobe at middle 6 

Length of posterior lobe to ends of angular processes 8i 

Width of anterior lobe at base 12 

Width of posterior lobe at base HJ 

Length of episternal prolongation 2i 

Width of episternal prolongation at base ^i 

Width of episternal prolongation near end ^'i 

Breadth of sternal bridges fore and aft ^ 

Breadth at ends of poststernal angular processes 'i 

Depth of poststernal notch 1 4 

Length of entosternal boue • - • ■ 4? 

Bi'eadth of entosternal bou(> ^i 



106 

In some low Ijuttes on the road to Carter Station, about three miles from 
Fort Bridger, Dr. Carter found a large turtle, which I viewed as jjertainiiig 
to Tcstudo Corsoni. As it lay partially exposed it measured about 2 feet 4 
inches in length, and approximated 2 feet in breadth. It was so much 
broken that in the attempt to remove it, it fell into a multitude of fragments. 

In Dry Creek Canon we discovered another turtle, which I viewed as T. 
Corsoni. The shell was in great part decomposed, but the rock which had 
occupied the interior still preserved its form. From this cast we estimated 
the shell to measure 28 inches long, 20 inches broad, and 14 inches high. 

Another specimen of a large turtle, discovered by Dr. Corson on the buttes 
of Dry Creek, consisted of fragments of a plastron with a few marginal plates 
of the carapace. The plastron, of which we have been enabled to restore 
the greater part of the anterior lobe, presents peculiarity enough to pertain 
to a distinct species from T. Corsoni. It was about the size and proportions 
of the plastron attributed to the latter, but the episternals are neither so 
aljruptly nor so much prolonged as in the former specimens, and the front 
part, as represented in Fig. 3, Plate XXX, is decidedly notched. The under 
surface of the extremity of the anterior lobe is flatter. 

The bony construction of the plastron, so far as preservecf, is the same as 
in the former specimens, and the entosternal is nearly of the same size and 
hape. 

The scute impressions are also the same as in the former specimens, except 
that the pectoral scute impressions arc nearly twice as long. 

Fragments from the back lobe of the plastron retaining the bottom of the 
poststernal notch indicate this to be more acute than in the former speci- 
mens. 

The measurements of the specimen are as follows : 

lutbes. 

Length of anterior lobe of the plastrou 8 

Breadth at base ]0J 

Length of episternal prolongation ] ;i 

Breadth of episternal prolongation at base 5i 

Breadth of episternal prolongation near the extremity 4^ 

Length of entosternal plate 4J 

Breadth of entosternal plate 5J 

Length of gular scute imi^ressions 3^ 

Length of humeral scute impressions 4J 

Length of pectoral scute impressions " 3 

Length of pectoral scute impressions where least , . . li 



s 



•I 07 

Portions of llic sliell ol' anolhcr specimen, apparently referable to Tesludo 
Corso)//, were discovered by Dr. Corson on Dry Creek Buttes. Several of 
the fragments so far recompose one side of the back lobe of the plastron as 
to determine its identity with that of T. Corsoni. It is especially interesting 
irom its being accompanied b}^ a number of fragments of the upper shell, 
wliich being reunited compose the middle portion, as represented in Fig. 1, 
Plate XXX. Tills specimen tends to confirm what I have latterly suspected, 
namely, tliat the specimens formerly described anil represented in Plate XI, 
under the name of Emys Carteri, really belong to Tesludo Corsoni. The 
specimens originally referred to the former, though much naore complete 
than the one upon which the latter was founded, completely misled me. The 
spade-like process of the plastron was not simply broken off, but, while 
imbedded in its matrix, was crushed or squeezed off in such a manner as to 
leave but little trace of its true character. The accompanying portion of the 
carapace exhibited the costal plates with strong costal capitula as in living 
species of Emys. This emydoid character with others are probably suffi- 
cient indications that the specimens would properly be referable to a genus 
distinct from either Testudo or Emys, and is probably the same as that 
recently proposed by Professor Cope, under the name of Hadrianus. 

The specimens originally referred to Emijs Carteri, 1)ut now viewed as 
pertaining to Testudo Corsoni, were discovered by Dr. Carter in the buttes 
near Fort Bridger. They consist of the greater part of a mutilated plastron 
with the ends broken off, and the anterior median portion of the carapace. 

The plastron represented in Fig. 1, Plate XI, resembles, in its size, form, 
and proportions, the nearly complete specimen above described and repre- 
sented in Fig. 2, Plate XXX. It is not so concave posteriorly, but other- 
wise presents nothing peculiar. 

The portion of the carapace represented in Fig. 2, Plate XI, consists of 
the nuchal and anterior three vertebral plates with fragments of the contig- 
uous costal plates. 

The anterior border of the fragment is slightly emarginate. The vertebral 
region is flat, and slopes forward from the anterior half of the first vertebral 
plate. The nuchal plate is nearly as long as wide, and its antero-lateral 
borders are moderately convergent. 

The first vertebral i)late is clavate in outline with the broad end behind. 
The anterior narrow end dips into an emargination of the nuchal plate. Its 
widest part is less than a fourili of its length in advance of its posterior 
■ 18 G 



138 

border. The second vertebral plate presents the usual hexagonal coffin-like 
outlhie, l)iit in a reversed' position, its broadest part being about one-fifth of 
ils length in advance of its liack border. Tlie third vertebral plate is oblong 
quadrate, with the fore and lateral borders convex, and the back one nearly 
straight. 

The sutures defining the first costal plate depart from the anterior narrow 
end and the posterior widest part of the first vertebral plate. The scute 
impressions of the carapace are well defined Ijy deep grooves. 

The nuchal scute impression is flat, and widens anteriorly. Tiie first mar- 
ginal scute impression is wider than long. 

The first vertebral scute area is longer than broad, and is purse-like in 
outline. 

The second vertebral scute area is also longer than broad, and is quadrate, 
with the lateral borders nearly parallel. 

The fragment of the carapace from its front border to the back l>order of 
the third vertebral plate measures 134 inches. 

Other measurements of the carapace are as follows : 

Lines. 

Length of nuchal plate 50 

Breadth of nuchal plate iu front 44 

Breadth of uuchal plate where widest GO 

Length of first vertebral plate 48 

Breadth of first vertebral plate in front 9 

Breadth of first vertebral plate where widest '. 30 

Breadth of first vertebral j)late at back border 14 

Length of second vertebral plate 27 

Breadth of second vertebral plate where widest 20 

Breadth of second vertebral plate at back border 10 

Length of third vertebral plate 29 

Breadth of third vertebral plate at middle 22 

Breadth of third vertebral plate at back border .■ 17 

Length of nuchal scnte impression 21 

Breadth of nuchal scute impression iu front 11 

Breadth of nuchal scute impression behind 

Length of first marginal scute impression 20 

Breadth of first marginal scute impression behind 38 

Length of first vertebral scute impression 07 

Breadth of first vertebral scute impression in front 32 

Breadth of first vertebral scute impression near middle r>2 

Breadth of first vertebral scute impression at back border 43 

Length of second vertebral scute impression 58 

Breadth of second vertebral scute impression at middle 48 

The accompanying plastron measured, in its complete condition, upward 

of 2 feet in length and about 1 i feet in breadth. 



139 

Other luoasunMnoiiis oftlio specimen are as I'ollovvs : 

Linos. 

Widtli of iinterior lob(^ of pliistrou at base lO.S 

Width of posterior lobe of plastron at base ll'l) 

Breadth of sternal bridyos fore and aft 114 

Length of entosterual plate 50 

Breadth of entosternal plate (i.'! 

Length of hyosteruals iu median line of plastron GO 

Length of hyposteruals in median line of plastron Gl 

Length of humeral scute impressions 48 

Length of pectoral scute impressions 2G 

Length of abdominal scute impressions 82 

Length of femoral scute impressions 47 

The portion of a carapace represented in Fig. 1, Plate XXX, and previ- 
ously referred to as tending to confirm tlie impression tiiat Emys Carterl was 
the same as Testudo Corsoid, retains most of the vertebral plates with contig- 
uous fragments of tlie costal plates. 

The anterior three vertebral plates, corresponding with those which are 
retained in the specimen originally referred to Emys Carteri, have the same 
form, but are wider. The succeeding two plates have the same form as the 
second vertebral plate in a reversed position. The sixth vertebral plate is 
too much broken to ascertain its exact form, but it would appear to be nearly 
the same as those in advance. The seventh plate is hexagonal, with the 
breadth more than twice the length ; and the eighth plate has the same form, 
but is not so broad. 

The length of the fragment of the carapace from the anterior broken end 
of the first vertebral plate to the back border of the eighth plate is 10 inches. 

Other meastirements are as follows : 

Lines. 

Length of first vertebral plate, estimated 40 

Breadth of first vertebral plate in front 14 

Breadth of first vertebral plate where widest ?>1 

Breadth of first vertebral plate at back border 17 

Length of second vertebral plate 27 

Breadth of second vertebral plate where widest 28 

Breadth of second vertebral plate at back border 18 

Length of third vertebral plate 28 

Breadth of third vertebral plate at middle -*3 

Length of fourth vertebral plate 20 

]3readth of fourth vertebral plate in front 29 

Length of fifth vertebral plate - 24 

Breadth of fifth vertebral plate in front 27 

Length of sixth vertebral plate 20 



140 

Linos. 

Length of seventh vertebral plate 13 

Breadth of seventh vertebral plate. 28 

Length of eighth vertebral plate 13 

Breadth of eighth vertebral plate 24 

The costal capitulti of Testudo Corsoni appear in the specimens as robust 
conical eminences, with a Ijroad, expanding base, and are proportionately 
better developed than in living species of Testudo, and even many of the 
species of Emys. 

Figs. 2, 3, Plate XXIX, represent the upper extremity of a humerus, and Fig. 
4 the lower extremity of a femur, which were found in association with the 
fragment of a carapace last described, and may reasonably be supposed to per- 
tain to the same animal. Both fragments resemble the corresponding parts 
of a modern Testudo. 

The head of the humerus has an inner trochlear extension, as in recent 
species of Testudo. Independent of this process, the transverse diameter of 
the head is nearly as great as the fore and aft diameter. In the specimen it 
presents a discoidal, flat surface, but this is evidently accidental. 

The measurements of the specimens are as follows : 

Lines. 

Breadth of humerus between tuberosities 29 

Breadth between outer tuberosity and inner extension of the head 32 

Breadth of the head with its inner trochlea _ 20 

Fore and aft diameter of the head 17 

Breadth of the distal end of the femur 2-1 

EMYS. 
Emys wyomingensis. 

Of the many remains of turtles from the Bridgcr Tertiary deposits I have 
had an opportunity of examining, most of them appeaf to me to belong to a 
species of Emys, which presents so much variation in anatomical details that 
the first specimens brought to my notice were viewed as pertaining to no less 
than four distinct species. These were named Emys imjomingensis, E. Steven- 
sonianus, E. Jeanesi, and E. Haydeni. A subsequent examination of ad- 
ditional specimens, collected by Dr. J .Van A. Carter and Dr. Joseph K. Cor- 
son, United States Army, and presented by them to the Academy of Natural 
Sciences of Philadelphia, has led me to regard all those indicated under the 
above names as really pertaining to a single species. I admit that I may be 
wrong in this determination, but if such is the case, it would appear that 
almost every specimen presents characters to distinguish a species. 



141 

Regarding all the specimens under consideration as pertaining to a single 
species, this would retain the original name of Emys wyomingensis. 

The composition of the shell so far as relates to the attachment of the 
carapace and plastron, the number of bones or plates and the number and 
relation of the corneous scutes, is the same as in living species of the genus 
Emys. 

In the mature condition, the shell of Emys ivyomingensis is upward of a 
foot in length, with about tliree-fourths the same measurement iu breadth. 

To what degree the shell varies in form, that is to say in relation of length 
and breadth with the height, and in outline, cannot be determined from the 
material at command, on account of the imperfection of the specimens, or 
their distortion from the original condition, due to pressure or to a crushing 
force applied to them while imbedded in the strata from which they were ob- 
tained. 

The elements of composition, especially the vertebral plates and scutes, 
differ more or less in different specimens, both in form and in the relation of 
length to the breadth. While the length of the vertebral scutes in general 
exceeds the breadth, especially in the case of those intermediate, in some 
specimens even to the extent of being a third greater, it nevertheless varies 
so much that in some instances it barely exceeds the breadth. The verte- 
bral plates vary in the same manner in different specimens, nor does this 
variation always accord with that of the same character in the vertebral scutes, 
that is to say the elongation of the scutes is not always accom|)anied in a 
proportionate degree with elongation of the plates. 

1. Emys tvyomingensis was originally described from an isolated episternal 
bone, sent to the writer by Dr. Carter. It was the first of the remains of 
turtles from the Bridger Tertiary deposits, which could be referred to the 
genus. It is represented in Fig. 5, Plate IX, and exhibits the usual form of 
that in living species, but further presents the appearance of being impressed 
by a narrow intergular scute. The presence of the latter I suspect to be ac- 
cidental or anomalous, though it may be normal, and may really indicate that 
the fossil belongs to a species distinct from those which I am now disposed 
to view as the same. The front of the specimen is truncated and slightly 
notched at the outer part. 

2, 3. Emys Stevensonianus is the name originally given to a supposed 
species founded on the specimens represented in Figs. 2, 4, Plate IX. These 



142 

were collected l)y Dr. Carter in the vicinity ot" Fort Bridger, and t<ent to the 
Smithsonian Iiistitntion, whence I obtained them for examination. The 
specimens consist of portion of a carapace, Fig, 2, and portions of two plas- 
trons, Figs. 3, 4. Slight difference in the corresponding portion of the latter 
specimens with that attributed to E. icyomingensis, but especially the absence 
of any evidence of an intergular scute, led to their being referred to another 
species. 

The sternal specimen, represented in Fig. 3, accompanied the portion of a 
carapace, represented in Fig. 2, and from its appearance was assumed to have 
belonged to the same individual. 

In the sternal specimen just indicated, the entosternal plate is lozenge-shaped 
in outline, l)ut constricted at the middle of its posterior part. Its length is 
equal to the breadth, but the evidence from the isolated episternal, first re- 
ferred to E. wi/ominge7isls, is that its entosternal was wider than long. 

The divisions of the plastron and its impress by scutes, as seen in the more 
perfect specimen, appear to agree pretty closely with the arrangement ob- 
served in ordinary living emydes. 

The second sternal specimen, represented in Fig. 4, was supposed to ])er- 
tain to the same species as the former one, though exhibiting differences 
whicli rather approached it nearer to that first referred to E. loyomingensis, 
except that it exhibited no trace of the existence of an intergular scute. The 
entosternal bone is wider than long, and without conspicuous constriction at 
its posterior part. The anterior truncated border of the episternuin is con- 
spicuously notched at its outer part. 

In all the sternal specimens indicated, the gular and humeral scutes have 
doubled over the edge and extended upon the upper surface in the same man- 
ner as in living emydes. 

In the carapaceal specimen, Fig. 2, the vertebral plates, consisting of the 
series from the first to the eighth, inclusive, successively decrease in length 
except that the third is a little longer than the second, and the llnirtli and 
ilflh arc nearly ecpud. To the fourth inclusive, the length much exceeds the 
breadth, but they successively diminish in this proportion. The fifth is but 
slightly longer than wide, and the remaining plates are much wider than long. 
The second and fifth are of the same width, and in this respect exceed the 
finst and intermediate ones, which are likewise of neai'ly uniform breadth. 
The sixth plate is the widest of the scries; the others successively diminish. 



143 

They exhibit Ihe usual ('onus, Ihc first l)ciiig oblong with the borders convex 
outwardly, the others to tiie lifth being wide coffin-shaped, and the remaining 
ones are more regularly hexagonal. 

The second and third vertebral scute-spaces are quadrate with the lateral 
defining-grooves strongly double sigmoid. The second space is Ijroader than 
long, but the third is the reverse. 

4. It was the nearly complete shell, represented in Plate X, which was 
attributed to a different species from the former specimens, under the name 
of Emys Jeanesi. This fine fossil was obtained near Fort Bridger, Wyoming, 
during Professor Hayden's exploration of 1870. It is considerably distorted 
from pressure, the right side being crushed inwardly so as to be nearly ver- 
tical. The shell, completely petrified like all its associate fossils, is filled 
with a greenish-gray sandstone. Its prominence or convexity in the original 
condition was perhaps not greater than in some of the ordinary living emydes, 
but it is apparently more prominent, from the lateral pressure to which the 
shell has been subjected. 

The carapace is oval in outline with the l>orders moderately deflected, 
acute, and without conspicuous indentations, except that it is slightly notched 
in the position of the nuchal plate. The plastron has the same form and 
degree of development in relation with the carapace as in living species of 
the genus. It is truncated in front, and notched behind. 

Although the sutures of the shell are conspicuously visililc, the bones or 
])lates are all closely united, and the specimen appears to have been nearly or 
quite in theadult condition. No lines of successive growth are visible on the 
plates, which are everywhere smooth. The position or boundaries of the 
scutes are indicated by deeply marked grooves. 

Ten vertebral plates appear to constitute the series, the connection of the 
last two in the specimen being destroyed. In form and proportians they bear 
a near likeness to those in ' emydes in general. They are rather wider pro- 
portionately than those in the specimen first referred to E. Stevemonianm, 
Init otherwise are sufficiently alike to pertain to the same species. 

As usual, the first vertebral plate is longest; then follows the third. The 
second, fourth, and tilth are nearly equal. The others, to the eighth, succes- 
sively diminish. The second vertebral plate is as wide at its fore part as it 
is long, but the succeeding two plates are considerably longer than wide. 



144 

The fiflli is as wide as it is long, and the remaining plates are considerably 
wider than long. 

The costal plates have about the same form as in recent species of the 
genus, but the first one is of greater proportionate breadth. Besides the 
nuchal plate, it articulates with four marginal plates. The remaining costal 
plates are of nearly uniform width as in recent eraydes. 

The second costal plate articulates with the fourth and fifth marginals ; 
the third, with the fifth and the anterior angle of the sixth marginals ; the 
fourth, with the sixth marginal alone ; the fifth, with the sixth and seventh 
marginals ; the sixth, with the seventh and eighth marginals ; the seventh, witli 
the eighth to the tenth marginals inclusive, and the eightli with nearly the 
whole of the tenth and tlie angle of the eleventh marginals. 

The marginal plates have nearly the same form and proportions as in recent 
emydes. 

The nuchal plate also has nearly the form and proportions as in the latter. 
The pygal plate, likewise, has the same form, but is proportionately smaller. 

The vertebral scute-tracts have nearly the same form as in living species of 
Emys, but the intervening ones are longer than wide. They are proportion- 
ately somewhat narrower than in the specimen first referred to E. Steven- 
sonianus. 

The first vertebral scute at its fore part extends outwardly nearly to the 
line between the first and second marginal scutes, and in this position is 
widest. 

The last vertebral scute, at its posterior border, crosses the last vertebral 
plate a short distance back of the middle. In recent species of Emys it 
impresses the pygal plate. 

The costal scutes resemble those of ordinary emydes, and as in these 
impress the marginal plates at their conjunction with the corresponding scutes. 

The nuchal scute is comparatively short and wide. The specimen being 
imperfect at the back part prevents us from ascertaining positively whether 
there existed a pair of pygal scutes as in living emydes, but an apparent curve 
upon the bone renders it probable that two also belong to the extinct species. 

The marginal scutes resemble those of recent emydes, but the anterior are 
wider than high, and the posterior, including the pygal scutes, are higher 
than wide. 

The fore part of the plastron has a half-oval outline shghtly projecting, and 



145 

fruiicated at the extremity as in ordinary emydes. The back part likewise 
has the same form as in the latter, and is also notched at the extremity. 

The pedicles are less elevated than in most recent emydes, and arc rather 
wider to the acute border of the carapace. 

The constitution of the plastron is so nearly like that of ordinary living 
emydes as hardly to need special description. 

The entosternal plate is nearly lozenge-shaped, and is widest transversely. 

The humeral scutes at their posterior border barely cross the posterior 
extremity of the entosternal bone. 

The pectoral and alxlominal scutes extend outwardly to conjoin the margi- 
nal scutes upon the marginal bones. In ordinary recent species of Emys the 
marginal scutes extend upon the hyosternal and hyposternal plates to join the 
pectoral and abdominal scutes. 

The axillary and inguinal scutes are large, and impress each a marginal 
and a sternal plate. 

The length of the carapace in a curved line is within half an inch of a foot 
and a quarter; its breadth, in the same manner, 11 inches; in a straight line 
it is little over a foot in length and about 10 inches in breadth. The plastron 
is less than a foot in length, and its pedicles measure, fore and aft, 4| inches. 

5. The specimen originally referred to Emys Haydeni is represented in 
Fig. 6, Plate IX. It consists of a portion of the carapace attached to a mass 
of indurated clay, and was obtained near Fort Bridger, Wyoming, during Pro- 
fessor Hayden's exploration of 1870. Since the specimen was figured, addi- 
tional portions of the shell have been found which allow the restoration of 
the fore part of the carapace. It belonged to a larger individual than the 
specimen first attributed to E. Jeanesi, and from the appearance of the mar- 
ginal border of several of the costal plates to a less mature one. 

The form of the carapace in front and its constitution in detail are very 
similar to the corresponding portion in the former specimen attributed to E. 
Jeanesi. The proportions of the vertebral plates is more nearly as in the lat- 
ter than in the specimen attributed to E. Stevensonianus. 

An apparently important difference between the fossil under examination 
and the one. attributed to E. Jeanesi is the less uniformity of width of the 
intermediate costal plates. These alternately become wider and narrower 
toward their outer extremities, whereas in the specimen referred to E. Jeanesi 
fliey are nearly uniform. 
19 G 



146 

As peculiarities of the Ibssil, tiie fourth vertebral plate is octagonal, and 
the fifth one in consequence quadrate. 

The second and third vertebral scute-tracts are much longer than wide, 
and proportionately much longer than in the former specimens. The anterior 
division of the second vertebral scute forms three sides of a square ; and the 
posterior groove defining the third scute crosses the sixth vertebral plate 
instead of the fifth as in the other specimens. 

The peculiarities indicated in the fossil under examination I regard as being 
of an individual character and in some degree anomalous. 

A fragment of the fore part of the plastron accompanying the specimen 
referred to E. Haydeni, and apparently belonging to the same individual, 
resembles the corresponding part in the specimens previously described, but 
is not notched at its anterior truncated border. 

6. Another specimen, referable to Emys wijomingensis, consists of a nearly 
complete shell except the posterior third of the carapace. It was discovered 
by Dr. Carter in the bluffs of the Cottonwood, seven miles from Millei'sville, 
in the vicinity of Fort Bridger, Wyoming, and presented by him to the 
Academy of Natural Sciences of Philadelphia. It is occupied in the interior 
with a greenish-gray sandstone, including indurated clay pebbles. In form 
and size it approaches closely the specimen first referred to Emys Jeanesi. 
In the forni and proportions of its vertebral scute impressions it more nearly 
resembles the specimen originally referred to E. Haydeni. The intermediate 
ones are, however, more strongly double sigmoid at their lateral borders; the 
fore part of the second vertebral scute is less square; and the anterior border 
of the third is strongly bowed forwarxl instead of being nearly straight. 

An accidental fracture of the specimen across the posterior third exposes 
to view the lateral supports of the carapace ascending from the plastron. 
These are much wider than in any of the living emydes, and approach in their 
proportions those of the living fresh-water turtle Batagur, of India. 

7. A seventh specimen oi E. wyomingensis consists of an intermediate ])or- 
tion of a carapace and nearly the whole of the sternum. It was obtained by 
Dr. Carter in the vicinity of Fort Bridger, and presented by him to the 
Academy of Natural Sciences of Philadelphia. 

The vertebral plates of the carapace are in general of proportionately greater 
l:)readth in comparison with the length than in the former specimens, and in 
this respect most nearly approach the one which was referred to E. Hay- 



147 

deni. The vertebral scute impressions likewise most nearly resemble those 
of the latter but are proportionately broader, and the posterior ]3order of the 
third vertebral scute crosses, as usual, the fifth vertebral ])late. 

The interior of the carapaceal specimen being freed from matrix, exhibits 
the costal plates with strong, well-developed costal capitula. 

The plastron is flat ; rather more strongly notched at its posterior extremity 
than in the former specimens in which it is preserved. 

The thickness of the costal plates ranges from 2 to 4-i lines. The thick- 
ness of the hyposternal plates internally ranges from 5^ to 8^ lines. 

8. An eighth specimen, consisting of the greater part of a plastron with 
fragments of the carapace, was ol)tained by Dr. Carter near Lodge-Pole Trail, 
thirteen miles southeast of Fort Bridger, and presented to the Academy of 
Natural Sciences. 

y. A fragment of a carapace, from Grizzly Buttes, presented to the Acad- 
emy of Natural Sciences l)y Dr. Joseph K. Corson, United States Army, 
has the intermediate scute impressions much longer than the width, not more 
so, however, proportionately, than in the nearly complete specimen numbered 
as the sixth. 

10. A similar fragment of an apparently young specimen, presented Ijy 
Dr. Carter, has the second vertebral scute impression nearly equal in length 
and breadth ; and the third one is but little longer than the breadth. Their 
lateral grooved borders are strongly double-sigmoid. 

11. Part of a carapace and. plastron of a still younger specimen, obtained 
]>y Dr. Carter near Lodge-Pole Trail, twelve miles southeast of Fort Bridger, 
nearly agrees in the form and proportions of its corresponding vertebral scute 
impressions with that last described. The second is nearly of equal length 
and breadth; the third and fourth are wider than the length. In its details 
of structure it accords sufficiently with the older and more complete specimens 
to render it probable that it pertained to the same species, except that the 
carapace is obtusely cnrinated its entire length. The entosternal bone is more 
rounded at its fore part than in previous specimens, and its length is alxtut 
equal to the breadth. 

12. A fragment of a plastron of another young individual, from the same 
locality and gentleman as the preceding, nearly agrees with the corresponding 
part. The entosternal is a httle longer than liroad, and is pyriform, with lat- 
eral projecting angles. 



148 

13. A specimen, apparently of a still younger individual of the same species, 
presented to the writer by Dr. Carter, was about the size of the palm of the 
hand. It consists of small portions of the carapace and more than half the 
plastron. The carapace is carinated as in specimen No. 11, and otherwise 
agrees with this in its details. The plastron has the same form as in the 
more complete and older specimens previously indicated, but the entosternal 
is more pyriform, considerably longer than wide, and the posterior defining 
groove of the pectoral scute crosses its middle. 

If it is admitted that the specimens Nos. 11 and 13 belong to Ejuijs 
wyomingensis, it would appear that the carinated condition of the carapace is 
a juvenile character, disappearing with growth. It would also appear that 
during growth the breadth of the entosternal plate became proportionately 
greater in relation with its length 

None of the specimens viewed as young ones exhibit upon the surface lines 
of growth, except the sternal one, No. 12, in which they are feebly marked. 
A distal fragment of several posterior costal plates of specimen No. 11, in the 
immature appearance of its border, clearly proves its youthfulness. 

Besides the thirteen characteristic specimens of E. loyomingemis which 
have been described or mentioned, fragments of many others are contained 
in the collections I have had the opportunity of examining. From their com- 
parative frequency, this appears to have been the most abundant of the fresh- 
water turtles of the Bridger Tertiary epoch. 

14. Since writing the foregoing, I have had the opportunity of examining 
another specimen of Emys wyomingensis in the possession of Dr. Ilirani 
Corson, which was sent to him from Fort Bridger by his son, Dr. Joseph K. 
Corson. Tlie specimen consists of a nearl}' complete shell except the posterior 
fourth of the carapace. It is a little smaller than the fourth-described speci- 
men, represented in Plate X, and is crushed and distorted nearly in a similar 
manner. 

The most striking peculiarities of this, which may be distinguished as the 
fourteenth specimen, are the unusual depth and width of the scutal grooves 
of the carapace and the proportionate shortness and breadth of the costal 
scute areas. 

The intermediate vertebral plates to the first and fifth are absolutely longer 
and narrower than in the ratlier larger fourth-described specimen. The costal 
plates are shorter, and (he second to (he four(h, inclusive, are broader. The 



149 

first and second vertebral scute aieas are wider and the third one lon<rer. 
The forms of the plates and scute areas indicated are nearly the same in both 
specimens. 

The plastron is slightly convex in both directions, and its extremities for 
half the length are more parallel at the lateral borders than in the fourth- 
described specimen. The axillary and inguinal scute areas are longer and 
narrower than in the latter, and somewhat modified in form. The length of 
the plastron in the median line is 11 inches. Other measurements in detail 
are given in the annexed table under the head of specimen 14. 

Comparative measurements of the specimens referred to Emys wyomingcn- 
sis are as follows : 



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154 

BAPTEMYS. 

A peculiar iiud interesting genus of extinct emydiform turtles, apparently 
intermediate in its characters to the existing American genera Dermatemys 
and Staurotypus, is founded on remains in the Bridger Tertiary formation of 
Wyoming. 

In shape and constitution, the shell of Baptemys (Plate XII) approaches 
most nearly that of Dermatemys^ more especially the carapace, while the 
sternum partakes of the character of that of Staurotypus. 

The carapace is oval in outline, apparently not wider behind than in front, 
and with the prominence or convexity about equal to half its breadth. The 
convexity is nearly uniform fore and aft, and laterally to the flexure of the 
marginal plates. The anterior border is bai'ely evei'ted and is thick and 
rounded. The imperfection of the fossils prevents a determination whether 
the posterior border departed from the general convexity of the liack of the 
shell. The surface formed hy the first and second marginal plates is feebly 
depressed. 

A median carina or thick rounded ridge starts upon the sixth vertebral 
plate and extends backward. 

Eleven vertebral plates enter into the constitution of the carapace. Those 
anteriorly are proportionately much longer than in emydes. They also appear 
proportionately of greater extent than in Dermatemys. 

The first vertebral plate is oblong, somewhat narrowed behind, and with 
the sides convex. Those to the sixth inclusive are hexagonal coffin-shaped. 
From the fifth they rapidly decrease in length to the eighth inclusive, and 
then increase again to the last. The seventh is niore uniformly hexagonal 
than the others. The ninth is quadrate and wider than long. The tenth is 
quadrate, widest behind, with the lateral borders convex and the back border 
concave. 

Tlie costal plates arc like those of Dermatemys, and as in this widen out- 
■ wardly more than in ordinary emydes in accordance with the greater convexity 
of the carapace. 

Tlie nuchal plate and marginal bones, so far as preserved, appear to be 
nearly as in Dermatemys. 

The scute impressions of the carapace, as in the latter, are not defined by 
such deep grooves as are usually observed in emydes. 



156 

The vertebral scute impressions have the same fonu niid general [iropor- 
tions as in Dermatemys. The first is wide, urn-like in outline, and is broader 
than long. The succeeding three are quadrate, with tlie length greatly ex- 
ceeding the breadth, and with the usual lateral brace-like or double-sigmoid 
borders. The last impression narrows for a short distance and then diverges 
in the usual manner. 

The costal scute impressions resemble those of emydes and extend farther 
upon the marginal bones than in Dermatemys, nearly reaching the middle of 
their outer face at the sides of the carapace, as far back as they are preserved 
in the fossils, as well as in front. 

The position of the nuchal scute is not preserved in the fossils, but the 
part immediately contiguous in one of them indicates tliat it had about the 
same proportions as in Dermatemys. 

The marginal scute impressions about occupied the lower two-thirds of 
the outer aspect of the marginal plates. The line intervening to the first 
two marginal scutes is continuous with that between the first vertebral and 
the succeeding costal scute. ' 

Considering the striking resemblance of the carapace of Baptemys to that 
of Dermatemys, it is not a little surprising to observe so much ditference in 
the plastron, though this also is nearly alike in the scute impressions. 

Compared with that of Dermatemys, the plastron is remarkably small, 
leaving proportionately much larger spaces in advance and behind the bridges 
for the movements of the animal. As before intimated, it is intermediate in 
character to that of the last-named genus and that of Staurotypus. The 
pedicles are intermediate in extent to what they are in the two genera just 
mentioned. The fore part of the plastron has nearly the same shape as in 
Dermatemys, but is widely emarginate at the extremity, and it is thick 
and rounded at the border instead of being acute as usual in emydes. The 
back part of the plastron is narrower than in Dermatemys, but less so than 
in Staurotypus. It terminates in a rounded extremity as seen in Fig. 2, 
Plate XII. In Dermatemys, it ends in a wide notch ; in Staurotypus, in a 
point. 

The entosternal lione is proportionately as large as in Dermatemys, and has 
nearly the same form. " The same may be said to be the case w'ith the epister- 
iials, (Fig. 6, Plate XV,) except that their anterior border is more conca,ve. 



156 

Tlie liyostcrnals and hyposlcrnals have nearly the same extent. Their 
intervening suture crosses the sternum near the middle of the pedicles. 

Dr. Gra}-, who established the genus Dermatemys, represents the South 
American species D. Mawii, with a pair of gular scutes. D. Berardii, of 
Mexico, is represented by Dumeril as possessing a single symmetrical gular 
scute, and this also is the case in two shells from Balize River, Yucatan, and 
Tabasco, Mexico, described by Professor Cope as pertaining to another species 
whicli he has named D. ahnormis. 

In Baptemys there is no trace of separation of gular scutes from the 
humeral scutes as indicated in Fig. 6, Plate XV. The grooves defining the 
latter from, the pectoral scutes occupy nearly the same position as in Derma- 
temys, crossing nearly through the middle of the entosternal plate. 

In Emys the gular and humeral scutes fold deeply upon the upper surface 
of the sternum, but in Baptemys, as is also the case in Dermatemys, the cor- 
responding scutes fold only to the upper edge of the rounded border of the 
sternum. 

The intervening grooves of the pectoral, abdominal, femoral, and caudal 
scutes nearly equally subdivide the sternum of Baptemys. 

The pectoral and abdominal scutes extend upon the sternal jjedicles, and 
are there separated from the marginal scutes by large intervening scutes, as 
in the sea-turtles and in Dermatemys. In the same position in Dermatemys 
ahnormis there are four of these scutes. In one of the specimens I have had 
the opportunity of seeing there are four of these scutes on one side and three 
on the other; but in this case it appears evident that the reduction is not the 
usual condition in the species. 

There are three scutes on the sternal bridge of Baptemys which succes- 
sively increase in size. The first or axillary scute joins the fourth and fifth 
marginal scutes and the pectoral scute. The middle or submarginal scute 
is hexagonal, widest transversely, and it joins the fifth and sixth marginal 
scutes and the pectoral and abdominal scutes. The third or inguinal scute, 
nearly twice the extent of that in advance, is also hexagonal. It extends 
across the hyposternal upon the hyosternal plate, and joins the sixth and 
seventh marginal scutes and the abdominal scute, an outward prolongation 
of which to the inguinal notch separates it from the femoral scute. 

The axillary fossa reaches as far back as the posterior third of the fourth 



167 

marginal bone ; the inguinal fossi extends forward nearly on a line witli the 
posterior border of the sixth marginal bone. 

The interior of the fossils being occupied by the rocky matrix, all the 
internal anatomical details are concealed from view. 

Baptemys in the relatively smaller size of the plastron to the carapace, and 
in the presence of submarginal scutes to the sternal bridges, is more nearly 
related to the marine turtles than the genus Emys. 

Baptemys appears also to have been nearly related with the equally ancient 
and extinct genus Pleurosternon, of the English Tertiary formation. In 
this the vertebral scute areas of the carapace are remarkable for their breadth, 
which considerably exceeds the length, whereas in Baptemys the intermediate 
Vertebral scute areas are much longer than liroad. The plastron in Pleuro- 
sternon is intermediate in its proportions to that of Emys and Baptemys, and 
has an additional pair of bones entering into its composition which do not 
exist in the latter genera. In Pleurosternon a pair of integular scutes inter- 
vene to the gular scutes ; in Baptemys there appears to be no distinction of 
gular scutes from humeral scutes. In Pleurosternon, as in Baptemys, large 
accessory or submarginal scutes intervene to the comparatively large axillary 
and inojuinal scutes. 



o^ 



Baptemys wyomingensis. 

The species thus named, as well as the genus, was first characterized from 
a beautiful specimen of the turtle-shell, discovered by Mr. 0. C Smith, of 
Leverett, Massachusetts, while engaged in the service of the Union Pacitic 
Railroad Company, near Fort Bridger, Wyoming Territory. The specimen 
was loaned to Professor Hayden, by whom it was sent to the writer for exam- 
ination. It is represented in Plate XII, one-third the natural size. 

The specimen consists of a shell which nearly retains its original form, but 
has lost the front marginal plates on one side, all those behind, most of those 
of the left, and the front part of the plastron. It is black, as is frequently 
the case with the fossils from the same locality ; and it is filled in the in- 
terior with a gray sandstone mingled wath coarse pebbles of indurated bluisii 
clay. 

In its perfect condition the shell has measured about a foot -and a half in 
length, and in breadth about a foot. Following the curvature of the carapace 



158 

fore and aft, it has measured about 20 inches in length, and the transverse 
arch from a level has been nearly as great. 

The length of the plastron has been about 11^ inches; its breadth from 
its sutural junction with the carapace is 9 inches. 

The sides of the plastron slope inwardly to a moderate degree. The pedi- 
cles are nearly on a level with the rest of the plastron, but are somewhat 
prominent in front and slope backward, and are concave approaching the 
inguinal fossaj. The rise of the shell appears mainly to commence in the 
marginal bones from the sternal pedicles ; to what degree is uncertain, as 
this part of the fossil is somewhat crushed inwardly. The rise is greater 
anteriorly, and gradually appears to subside liehind. 

The fore and aft extent of the pedicles is 4^ inches. The length of the 
anterior extension of the plastron has been about 3J inches ; its breadth at 
the bottom of the axillary fossse is 5J inches. The length of the posterior 
extension of the plastron is a little more than 3^- inches, and its width at the 
bottom of the inguinal fossae nearly 4^ inches. 

The marginal bones appear more abruptly bent to join the sternal bridge 
than in Dermatemys, but the difference is partially due to the crushing 
inward of the under part of the shell in the fossil. 

A second specimen of the shell of Baptemys wyomingensis was subse- 
quently discovered during' Professor Hayden's exploration of 1870 at Church 
Buttes, Wyoming. The shell is of a different color, and is filled with and 
partially imbedded in a different matrix from the former specimen. The 
bones are brown, and the matrix consists of a very hard sandstone. The 
specimen, though fiir less complete than the former, fortunately retains one- 
half of the anterior part of the plastron. Most of the carapace is lost or 
imbedded in the hard rock. The sternum on one side from its fore extremity 
to the commencement of the xiphisternal bone, together with the pedicle and 
its characteristic scute impressions, is well preserved. 

The measurements of this second specimen indicate an individual of the 
same size as the former. Slight differences existing between corresponding 
parts of the two appear to be variations only of an individual character. In 
the second specimen tlie large inguinal scute passes just over the back edge 
of the hyosternal plate, while in the former one it extends upon it for half 
an inch. 



159 



Measurements derived mainly from the more complete specimen arc as 

follows. 



Length. 



First vertebral plate . . . 
Second vertebral plate. 
Third vertebral plate . . 
Fourth vertebral plate. 
Fifth vertebral plate . . . 
Sixth vertebral plate . 
Seventh vertebral plate 
Eighth vertebral plate . 
Ninth vertebral plate . 
Tenth vertebral plate. . 



Lines. 
27 
22 
23 
22 
32 
17 
10 
7 
9 
13 



Breadth. 



Linen. 
]3 
14 
14 
. 14 
15 
IG 
17 
12 
14 
16 



Leuffth. 



Width 
iuterually. 



Width 
externally. 



F'irst costal plate . . 
Second costal plate 
Third costal plate. . 
Fourth costal plate . 
Fifth costal plate . 
Sixth costal plate . 
Seventh costal plate 



Lines. 

45 
GO 
70 
73 
GO 
GO 
47 



Lines. 

2G 
24 
24 
22 
20 
17 
15 



Lines. 
37 
2G 
27 
24 
30 
22 
20 



The nuchal plate fore and aft has been about 2f inches ; its breadth about 
an inch greater. 

The marginal bones, so far as preserved, appear to have nearly the propor- 
tions and aspects as in Dermatemys. Their vertical measurement is about 
2 inches, and their width about the same. 

The measurements of the scute impressions are as follows: 




lireadth. 



First vertebral scute impression . . 
Second vertebral scute impression 
Third vertebral scute impression . . 
Fourth vertebral scute impression 

First costal scute at middle 

Second costal scute at middle 

Third costal scute at middle 



Lines. 

52 
30 
33 
32 
5G 
4G 
4G 



160 

The episternals at their uiiier border measure 1 inch ia length ; at their 
posterior extremity 10 lines. 

The entosternal bone is 2J inches fore and aft, and 2f inches wide. 

In the better preserved of the two specimens the plastron presents the 
irregularity of having the left hyposternal and xiphisternal near half an inch 
more produced forward than npon the right side, as seen in Fig. 2, Plate XII. 

Measurements of the remaining sternal bones are as follows : 

Lines. 

Length of right hyosterual internally 30 

Length of left hyosterual internally 25 

BreadtJi of hyosternals at middle 58 

Length of hyposternals internally 34 

Breadth of hyposternals at middle 52 

Length of right xiphisternal internally 34 

Length of left xiphisternal internally 40 

Breadth of anterior border 24 

Measurements of the scutes are as follows : 

Lines. 

Length of gular-humeral scute internally 28 

Breadth of gular-humeral scute posteriorly 26 

Length of pectoral scute internally 18 

Breadth of pectoral scute posteriorly 36 

Length of abdominal scute internally 29 

Breadth of abdominal scute posteriorly 28 

Length of femoral scute internally 26 

Breadth of femoral scute posteriorly 22 

Length of caudal scute internally 27 

Axillary scute obliquely from within outward 32 

Axillary scute at posterior border 13 

Middle scute of sternal bridge fore and aft 17 

Middle scute of sternal bridge at middle, transversely 25 

Inguinal scute fore and aft 32 

Inguinal scute at anterior border 13 

Inguinal scute at middle between prominent angles , 29 

BAENA. 

By this name I have distinguished a remarkable genus of turtles, indicated 
by remains in the Bridger Tertiary beds. It partook of characters of the 
snappers or chelydroids, the terrapins or emydoids, and the sea-turtles or 
chelonioids. The specimens upon which the genus is founded consist of shells, 
which are mostly so much crushed and distorted as to render it somewhat 
uncertain as to their exact original and perfect form. They were apparently 
about as prominent as in our snapper, and had nearly the same outline of shape. 
Tlie middle of the carapace is not depressed as in the latter, but is somewhat 



161 

flattened, and forms a continuous convexity with tlic sides. The posterior 
extremity presents a deep emargination as in the snapper, and on each side is 
notched likewise as in the latter. 

The plastron of Baena is emydoid in character, and in its degree of develop- 
ment in relation with the carapace approaches that of its associate genus Bap- 
temys. As in this, large spaces exist between the extremities of the plastron 
and carapace, but comparatively of much less extent than in Chelydra. The 
pedicles of the plastron are immovably conjoined with the carapace. They 
are as wide relatively as in the emydoids, but are much longer. The two 
extremities of the plastron are nearly alike in shape, being tongue-like and 
feebly emarginate at the end. 

The number, arrangement, and general form of the corneous scutes of the 
carapace appear to have been the same as in Emys and Chelydra. The plastron 
exhibits two pairs of gular scute areas, which, together with the other scute 
areas, made seven pairs to the plastron. In addition to these the pedicles 
exhibit a row of scute areas between the former and the marginal scute areas 
of the carapace, as in the sea-turtle, the snapper, Dermatemys, and Baptemys. 

A feature which may be regarded as a character of Baena is the obliteration 
• of the sutures, and the shell at maturity has the bones so co-ossitied that their 
original boundaries cannot be traced. 

The true ribs or costal arclies, connate with the costal plates, are remark- 
ably prominent in Baena, and the costal capitula are well developed. In 
several specimens, in which portions of the carapace. arc broken away, the 
mass of rock within exhibits deep concave grooves indicating the former 
position of the rib-arches. 

The sustaining columns of the carapace, springing as processes from the 
hyosternal and hyposternal bones of the plastron, are of great comparative 
breadth, and subdivide the interior of the shell into three compartments as in 
tlie Batagur, a genus of fresh-water turtles now living in India. 

Baena arenosa. 

The species thus named was originally founded on a specimen consisting 
of a nearly complete turtle-shell discovered at the junction of the Big Sandy 
and Green Rivers, Wyoming, during Professor Hayden's exploration of 187U. 
The specimen is represented in Figs. 1, 2, Plate XIII. 

The shell, besides appearing to be in some degree crushed downward or 
21 G 



1G2 

flattened, has lost the fore part and right border of the carapace. The plas- 
tron, less injured, has lost its anterior extremity. 

The outline of the carapace appears to have been broadly oval; and the 
shell was apparently not more elevated than in our common snapper. 

All the bones of the carapace and plastron are so intimately co-ossified that 
the position of the former sutures cannot be detected. The grooved bound- 
aries of the scutal areas are, on the other hand, vv^ell marked. 

The carapace corresponding with the position of the intermediate vertebral 
scutes is flattened and slightly depressed at the middle. It is most prominent 
along the lateral boundaries of the vertebral scutes. In the position of the 
last of the latter it is most prominent at the middle. No distinct carination 
exists, but a feeble and widely interruj^ted ridge occupies the median line of 
the carapace, scarcely noticeable were it not better developed in other speci- 
mens. The sides of the carapace slope evenly outward to the rounded flex- 
ure of the lateral marginal plates. 

The posterior marginal plates are notched as in the snapper, and are slightly 
recurved at the prominent ends. Between the last pair, of marginal bones a 
wide concave emargination exists, as in Chelydra, but of less depth. 

The intermediate vertebral scute tracts are nearly square, and are as broad • 
as, or a little broader than, long. The lateral grooves have the usual brace 
form. The groove between the second and third tracts is convex forward ; 
the succeeding' one much less so; and that between the fourth and fifth tracts 
is much produced forward with a mammiform outline. 

The costal scute tracts are nearly like those of Emys and Chelydra. Their 
grooves are directed nearly parallel outwardly, except the extreme back and 
front ones. 

The plastron appears quite flat and nearly on the same level with its pedi- 
cles, but this condition is evidently in some degree the result of accidental 
l^ressure from above. The posterior extremity is broad, linguiform, with the 
end slightly and concavely emarginate. 

The pectoral scute impressions, as in the Chelydra, are larger than any 
others of the plastron. They extend outwardly on half the breadth of the 
sternal bridges. Tiie anterior groove is directed outwardly on a level with 
the bottom of the axillary fossae, and near its end turns abruptly and obliquely 
forward to the edge of the latter. 

The abdominal scute impressions, shorter than those next in front and 



163 

behind, extend upon the posterior half of the breadth of the sternal bridges. 
Their posterior groove is directed obliquely outward and backward to the 
bottom of the inguinal fossae. 

The femoral are considerably lai'ger than the costal scute impressions, and 
defined from them by a sigmoid groove. 

The bridges of the plastron present a row of four large scutal areas inter- 
vening between the pectoral and abdominal scute areas internally, and the 
marginal-scute areas of the carapace externally. The first and last of these 
may be regarded as homologues of the comparatively small axillary and ingui- 
nal scute areas of Emydes; the intermediate ones are superadded. 

The axillary scute area, partially broken away in the specimen, appears to 
have had four borders, of which the anterior formed the outer boundary of 
the axilla, and the internal joined the pectoral scute area. 

The second submarginal scute area, the smallest of the series, is quadrate, 
and internally joins the pectoral scute area. The succeeding submarginal 
area, larger than those in advance, is pentagonal, with the two shorter sides 
forming a projecting angle joining the pectoral and abdominal areas. 

The inguinal scute area, larger than the others, has four borders, of which 
the internal joins the abdominal area, and the posterior bounds the greater 
part of the bottom of the inguinal space. 

The surface of the carapace is somewhat irregular ; that of the plastron is 
more regularly and minutely roughened or fretted in appearance. 

A second nearly complete specimen of a shell of Baena was discovered by 
Dr. J. Van A. Carter at Church Buttes, on Black's Fork of Green River, three 
miles north of Fort Bridger, and was obligingly sent to the writer as a gift. 
The shell, like the former one, is considerably crushed, so as to render an 
exact determination of its original form uncertain. It approximated the other 
specimen both in shape and size, and, like it, has all the bones so completely 
co-ossified that their limits are obliterated. 

This second specimen presents several differences from the former one, 
which led to its having been considered as pertaining to another species, to 
which the name of B. affinis was given. Additional specimens since obtahied 
and exhibiting other variations have led to viewing all of them as belonging 
to a single species. 

The carapace measures 13 inches in length following the curvature. Its 
anterior portion, preserved in the specimen on one side, has a rather obtuse 
border, and is not recurved. In front it is prominent, as far as seen in the 



164 

specimeii, currespoiuliug with the position of what appears to be tlie outer 
portion of the nuchal scute area. The latter apparently is of great width, at 
.least an inch at its conjunction with the first vertebral scute area. 

The latter and tlic last of the series are prominent in the median line, where 
they form a thick, rounded ridge. A low interrupted ridge extends along the 
median line of the carapace, which is barely evident in the first-described 
specimen. The short divisions of the ridge are flanked by equally long fusi- 
form elevations slightly divergent forward. In addition, the carapace is 
rather irregularly prominent along the position of the lateral grooves of tlie 
vertebral scute areas. The intermediate vertebral scute areas are proportion- 
ately narrower than in the first specimen. The second and third are slightly 
longer than wide; the fourth a little wider than long; and the first and last 
in width considerably exceed the length. 

The jilastron is preserved nearly complete, and is represented in Fig. 3, 
Plate XIII. It appears as if originally it had been less flat than in the former 
specimen, as, inde])endently of fractures, it turns up more at the extremities 
as well as at the bridges. 

The anterior extremity, which is lost in the former specimen, affords an 
opportunity of completing our knowledge of the plastron. It is shorter and 
narrower than the posterior extremity, but is nearly like it in shape. The free 
border is obtusely rounded, and is slightly more thickened and prominent at the 
divisions jJroduced by the scute impressions. These do not mark the upper sur- 
face as in the Emydte. The lower surface exhibits one of the most remarkable 
peculiarities of the genus, which is the possession of two pairs of gular scutes. 

The first pair of gular scutes are comparatively small, and are defined poste- 
riorly, in, the usual manner, by oblique grooves diverging at an angle' of 45°. 

The second pair of gular scute impressions escaped my notice until I had 
seen several additional specimens. As this did not occur until after the draw- 
ing of Fig. 3 was made, they are not there represented. They are seen in 
Fig. 1, Plate XV, which was subsequently and more accurately drawn from 
the same specimen. They are rather larger than the first [)air, and are 
defined posteriorly by a serpentine groove directed outwardly nearly from the 
same point as the grooves in advance. 

The remaining scute areas of the plastron are nearly like those of the pre- 
ceding specimen, except those covering the pedicles. 

Only three scutes covered the latter in the second specimen, the one cor- 
responding with the first submarginal scute area of llie first specimen being 



165 

deficient. Ta conscqueticc of its absence, a modification of tlie outlines ol' t he 
contiguous ones resulted. The posterior groove of the axillary scute, and the 
anterior groove of the area corresponding with the second submarginal scute 
in the first specimen, instead of being transversi; are oblique and join each 
other at an angle externally. The posterior two scutal areas also dilfer from 
those of the first specimen in being separated l:)y a groove directed obliquely 
outward and backward instead of nearly transversely. 

The surface of the plastron exhibits tlie same minutely fretted appearance 
as in the tbrnier specimen. 

In the perfect condition the two specimens of Baena which have been de- 
scribed differed but little in size. The length of the carapace in a straight line 
has approximated 13 inches, the breadth 9 or 10 inches. The length of the plas- 
tron is 11 inches; its breadth to its conjunction with the carapace about 8 inches. 

A third and less perfect specimen of the shell ef Bac7ia areiwsa, consisting 
of the central portion of the carapace and nearly the corresponding portion 
with the anterior extremity of the plastron, was found l^y Dr. Carter on 
Henry's Fork of Green River, and presented by him to the Academy of 
Natural Sciences. 

This specimen had about the same size as the previous ones, and like them 
has all the bones completely co-ossified. The median ridge of the carapace is 
more distinct than in the other specimens, and its divisions appear more or 
less distinctly to mark the position of the vertebral plates, while the lateral 
diverging prominences also appear to mark the sides of these plates. • 

The intermediate vertebral scute areas are intermediate in proportions to 
those of the former specimens. 

The surface of the plastron is smooth and exhibits no trace of the minutely 
fretted condition observed in the former specimens. The grooves defining 
the sternal scute impressions, the median groove as well the more transverse 
ones, are less regular in their course than in the other specimens. 

The anterior extremity of the plastron, represented in Fig. 2, Plate XV, is 
flat, and exhibits the second pair of gular scute areas larger than in the former 
specimen in which they exist, while their more tortuous back groove starts 
from the median groove a half inch behind that in front. The rounded bor- 
der is more prominent in the position of the gular scute impressions than in 
the former specimen. 

A small part of the sternal bridges retained in the specimen shows a por- 



1(56 



tioii of ilie second subinarginal scute area witli an internal projecting angle 
intermediate in extent to that of the former specimens. On one side, also, a 
small portion of the tirst submarginal area is retained, and this appears to 
indicate that it was nearly of the size and shape of that in the first-described 
specimen of Baena. 

Comparative measurements of the three described specimens of Baena 
arenosa are as follows : 



Leugth of first vertebral scute at middle 

Breadth of first vertebral scute at middle 

Leugth of second vertebral scute at middle 

Breadth of second vertebral scute at middle . 

Leugth of third vertebral scute at middle 

Breadth of third vertebral scute at middle 

Length of fourth vertebral scute at middle 

Breadth of fourth vertebral scute at middle 

Length of fifth vertebral scute at middle 

Breadth of fifth vertebral scute at middle 

Width of first costal scute internally 

Width of second costal scute internally 

Width of third costal scute internally 

Width of fourth costal scute internally 

Length of anterior prolongation of the plastron 

Breadth at base of anterior prolongation of the plastron . . 

Length of posterior prolongation of the plastron 

Breadth at base of posterior i^rolongation of the plastron . 

Breadth of pedicles of plastron 

Length approximately of pedicles of plastron 

Leugth of gular scutes internally 

Breadth of gular scutes at back border 

Length of humeral scutes internally 

Breadth of humeral scutes at back border 

Length of pectoral scutes Internally 

Breadth of pectoral scutes at middle 

Breadth of pectoral scutes at back border 

Length of abdominal scutes internally 

Breadth of abdominal scutes at middle 

Breadth of abdominal scutes at back border 

Length of femoral scutes internally 

Breadth of femoral scutes at back border 

Length of caudal scutes internally 

Fore and aft diameter of first scute of pedicle 

Fore and aft diameter of second scute of pedicle 

Fore and sjft diameter of third scute of pedicle 

Fore and aft diameter of fourth scute of pedicle 



Liues. 



36 
30 
35 
37 
29 
37 
32 
48 



37 
32 
21 



46 

48 
50 
62 
26 



24 
32 
41 
31 
15 
41 
34 
28 
21 
21 



16 
20 

99 



Lines. 



22 
36 

35 

30 

35 

31 

28 

30 

26 

40 

34 

36 

30 

17 

35 

41 

48 

52 

58 

24 

10 

14 

26 

19 

24 

45 

31 

22 

38 

29 

26. 

22 

22 

18 



24 
20 



Lines. 



35 
32 
34 
32 



33 



38 
30 



37 

44 



52 
56 
24 
10 
15 
21 
22 
22 
50 
33 
20 
44 
28 
24 
19 



1G7 

A fourth specimen referable to Baeiia arenosa consists of a small portion of 
the carapace with a large portion of the plastron, from Henry's Fork of Green 
River, found by Dr. Carter, and presented by him to the Academy of Natural 
Sciences of Philadelphia. This exhibits no peculiarity, excepting that the 
scutal grooves of the plastron are more irregular in their course than in the 
preceding specimens. The median groove of the plastron is especially tor- 
tuous, while in the other specimens it is nearly straight. A retained portion 
of one of the sternal bridges exliibits evidences that four scufes impressed 
them, arranged nearly as in the first-described specimen of Baena. The sur- 
face of the plastron is less smooth than in the previous specimen, but it does 
not present the fretted appearance of the two former ones. 

A fifth specimen, apparently referable to B. arenosa, consists of the anterior 
extremity of a plastron, represented in Fig. 3, Plate XV. It was found at 
Grizzly Buttes by Dr. Joseph K. Corson, and by him presented to the 
Academy of Natural Sciences. It would appear from its size as if it had 
belonged to a larger individual than the preceding specimens. It is nearly 
flat, or in a trifling degree convex, and is smooth, or without any appearance 
of fretting. It exhibits the four gular scute areas of unequal extent. 

Another specimen, consisting of the anterior extremity of a plastron, appar- 
ently of 'a young animal of the same species, is represented in Figs. 4, 5, 
Plate XV. The specimen was found at the junction of the Big Sandy and 
Green Rivers, Wyoming, during Professor Hayden's exploration of 1870. 

In this specimen the sutures are visible, and the contiguous bones defined 
The grooves defining the two pairs of gular scutes start all from the same 
point, which is near the center of the entosternum. The entosternal bone 
viewed below is pyrilbrm, but in the reverse position to that ordinarily 
observed in emydcs. Viewed above, it resembles that of the snapper, 
(Cheli/dra,) or that of the sea-turtle, {Ckelove.) In front it is received 
between the episternals ; behind, it forms two lateral barljs projecting 
obliquely outward between the episternals and the hyosternals, and a long, 
median, pointed process extending between the hyosternals. The episternals 
posteriorly are angular, and are there received into a notch of the hyosternals. 

From the matrix of the first-described specimen of the shell of Baena I 
obtained a portion of the pelvis, which presents some anatomical points of 
importance. 



168 



Comparative measurements of the anterior extremity of the plastron, where 
this is present in the specimens, are as follows : 





First 
specimen. 


Second 
specimen. 


Third 
specimen. 


Fourth 
specimen. 


Sixth speci- 
men, yonng. 


Length of plastrou to anterior pectoral 
groove . ... 


Lines. 


Lines. 
34 
30 
28 
18 


Lines. 
30 
43 
28 
18 


Lines. 

37 

44 

■ 
34 

20 


Lines. 


Breadth of plastron at anterior pectoral 


44 




Breadth of plastron at anterior humeral 


20 


Breadth of plastron at middle gular 
groove 




13 









The pelvis is more expanded above than in Emj^s, and in this respect is 
more like that of the snapper. The sacrum represented in Fig. 9, Plate 
XVI, is intermediate in its proportions to that of the two genera just men- 
tioned. 

The length of the sacral vertebrae of Baena, independently of the wings or 
transverse processes, exceeds the breadth, the proportions in this respect 
according more witli the condition in the terrapin than in the snapper. Tlie 
second sacral vertebra is, however, larger than the first, as in the latter turtle, 
and the reverse of what it is in the former. The inferior surface of the 
bodies of the sacral vertebrse is half cylindroid, depressed at the sides in the 
first one, but scarcely so in the second. 

The anterior articular surface of the first sacral centrum is moderately 
convex ; the posterior articular surface of the second centrum is concave. In 
Emys the corresponding surfaces are flat, or nearly so; in Chelydra the ante- 
rior one is concave, the posterior convex, with lateral extensions nearly flat. 

The proportionate length and robustness of the sacral ala3 of Baena agree 
more nearly with the condition in the snapper than in the terrapin. In Emys 
the posterior alse are comparatively feeble appendages, and they join the ends 
of the anterior alse by means of a hgaraent. In Baena the posterior alse are 
strong processes, as in the snapper, and likewise, as in this, join the ends of 
the alee in advance by suture, but appear not to be prolonged to join the 
ilium. 

The innominatum of Baena, as represented in Fig. 8, Plate XVI, is proper- 



169 

tionately of more robust cliaracter than in Erays. The ilium in filunx! is 
more like that of this genus than that ot the snapper, l)ut is proportionately 
ol' much greater breadth, the wing being of nearly double the expanse. 

The expanded extremity of the first sacral wing articulates with the ante- 
rior extremity of the crest of the ilium. In Emys it articulates with the 
latter midway to the two prominent extremities of the crest. 

The acetabuhim and commencements of the ischiatic and pubic rami pi-e- 
sent nothing peculiar from the condition observed in the snapper. 

Measurements of the pelvic specimens are as follows : 

Lines. 

Length of sacrum beneatli the centra 9j 

Length of first sacral centrum 4^ 

Breadth of first sacral centrum .■ 4.J 

Length of second sacral centrum 4^ 

Breadth of second sacral centrum 4? 

Breadth of sacrum at first pair of alae 30 

Length of first saci'al alae , 13 

Length of second sacral alaj 11 

Length of innominatum 23 

Breadth of crest of innominatum 18 

Height of acetabulum C 

Breadth of acetabulum 9J 

CHISTERNON. 

Chisternon undatum. 

A large turtle-shell, discovered by Dr. Carter in a chain of buttcs a few 
miles from Fort Bridgcr, and presented to the Academy of Natural Sciences 
of Philadelphia, was originally described by me under the name of Baena 
undata. A careful examination of the specimen has led me to view it as per- 
taining to a different and heretofore undescribed genus. 

The specimen represented in Plate XIV, one-half of the diameter of nature, 
consists of the intermediate portion of a shell, with the extremities broken 
away nearly in the position of the broad columns wliich spring from the plas- 
tron to support the carapace. Though much fractured, it appears to have 
been but little so while it lay imbedded in the deposit from which it was 
derived, so that it now retains its orginal form. The upper shell is as mucli 
vaulted as in some of the living land-turtles. This form, together with the 
thick bone and strong, broad sternal supports, enabled it to sustain tlic grt'ut 
weight of superincumbent pressure which has crushed so many of its asso- 
22 G 



170 

ciates. The interior of the shell is occupied by a greenish-gray sandstone, 
from which I obtained a pair of sacral vertebrae. 

The outline of the shell in its perfect condition was ovoid as in ordinary 
Emydes ; narrower and more elevated in front, wider and more depressed 
behind. The fore part and sides of the carapace are uniformly convex, but 
the hind part appears to have had the margin somewhat recurved. Over the 
position of the vertebral scute areas the surface is flat and even and without 
a carina. The plastron is flat, but its bridges turn from their commencement 
upward and outward to the border of the carapace, which is elevated 2^ 
inches above the level. The highest part of the shell is nearly 6 inches 
above the level of the plastron. The bones of the shell, especially those of 
the carapace, appear co-ossified, but not so completely as in Baena arenosn, 
for those of the plastron can be distinctly traced. 

The intermediate vertebral scute areas have nearly the form and propor- 
tions of those of Baena arenosa, and are rather longer than wide. The costal 
scutes widened more outwardly than in that turtle, indicating a proportion- 
ately greater degree of prominence of the shell. 

The lateral marginal scute areas are much like those in Emydes, but the 
groove defining them from the costal scute areas exhibits an unusually undu- 
lating course, not angular but serpentine or waving. 

The number and relative position of the scute areas of the plastron and its 
bridges are the same as in Baena, but the median sternal groove defining 
them on the two sides is remarkable for its irregular serpentine course, 
repeatedly crossing the also somewhat irregular course of the median suture 
of the plastron. 

The sutures of the plastron being visible, they reveal to us an unexpected 
peculiarity, the existence or absence of which cannot be determined in the 
shells of Baena arenosa from the total obliteration of the sutures. 

The peculiarity in the plastron of Chisternon, to which the genus owes its 
name, is the presence of a large triangular bone, added to those which usually 
exist in turtles, on each side of the shell. This intercalated or mesosternal 
bone commences at the center of the plastron and gradually widens outwardly 
to where it conjoins the marginal plates of the carapace at the intermediate 
half of the sternal bridge. The four sutures defining the mesosternal plates 
from those in front and behind cross the plastron obliquely. A similar bone 



171 

exists in another extinct genus, the Pleurosternon, dI' the early Tertiary for- 
mation of England, but in this it has the shape of a parallelogram. 

The sternal bridges of Chisteriiou present four large scutal areas nearly 
resembling those of Baena arenosa. They are not quite symmetrical on the 
two sides. 

The axillary scute area is pentagonal, and is the smallest of the series. 
The anterior border is oblique, and. bounds the axillary notch externally. 
Two outer borders form an obtuse angle and join the third and fourth mar- 
ginal areas. The inner border joins the pectoral area. 

The second submarginal area is second in size of the series. It is longer 
than l)road, and nearly quadrate, but has its outer angles cut off. The inner 
border conjoins the pectoral area; the outer the fourth and fifth marginal 
areas. 

The third submarginal area is but little larger than the axillary area. It 
joins the pectoral and abdominal areas internally, and the fifth and sixth 
marginal areas externally. 

The inguinal area, the largest of the submai'ginal areas, is obliquely quad- 
rate, longer than broad, and with the outer angles cut off. The posterior 
border bounds the inguinal notch ; the inner border joins the abdominal area, 
and the outer border joins the sixth, seventh, and eighth marginal areas. 

The inferior surface of the plastron is comparatively smooth. Striatious 
cross the sutures, and elsewhere it presents a finely reticulo-vascular appear- 
ance. 

The fractured condition of the shell affords us an opportunity of seeing 
the strong hyosternal and hyposternal columns which aid in sustaining the 
cai'apace. These columns are broad, vertical plates reaching far into the cav- 
ity of the shell and dividing it into three compartments, as in the Batagur of 
India. 

The hyosternal columns are 2\ inches wide from their inner concave bor- 
der to the axilla. The aperture of the shell between them is a doorway 3 
inches wide near the roof and 4^ inches near the floor. The hyosternal col- 
umns, partially exposed in the specimen, appear to be co-extensive with the 
anterior supports. 

The breadth of the shell of Chisternon undatum, between the lateral 
obtuse borders of the carapace, is 15 inches. The length of the shell, or of 
the carapace, in a straight line is estimated to have been about a foot and a 



172 

half. The length of" the plastron is estimated to have been about 14 inches; 
its breadth at the root of the posterior extremity is 5^ inches; and at the root 
of the anterior extremity has been rather less. The sternal bridges measure 
7 inches fore and aft, and their length to the outer edge of the carapace is 5 
inches. 

Other measurements of the shell are as follows : 

Inches. 

Length of second vertebral scute area, estimated at 4 J 

Breadth of second vertebral scute area 3^ 

Length of third vertebral scute area 4J 

Breadth of third vertebral scute area 3i 

Length of fourth vertebral scute area Si 

Breadth of fourth vertebral scute area 3i 

Breadth of second costal scute area, internally 4| 

Breadth of second costal scute area, externally 4J 

Breadth of third costal scute area, internally 3§ 

Breadth of third costal scute area, externally 3^ 

Height of sixth and seventh marginal scute areas 2.J 

Length of hyposternals internally 5 

Breadth of hyposternals internally 5^ 

Breadth of hyosternals Sf 

Breadth of plate intercalated between the hyosternals and hyposternals G 

Extent of the same plate at the base externally, fore and aft 4f 

Breadth of groove between pectoral and abdominal areas where it joins the pro- 
jecting angle of the third sterno-costal scute areas 7J 

Breadth of plastron at anterior suture of xiphisternals 4i 

Breadth of pectoral scutes to sterno-costal scutes 4 and 4^ 

Length of abdominal scute internally 3 

Length of femoral scute internally 3^ 

Axillary scute area, length at middle 1^ 

Axillary scute area, breadth at middle 2i 

First submarginal scute area, length at middle . . 2i 

First submarginal scute area, breadth at middle. . 2^ 

Second submarginal scute area, length at middle 2 

Second submarginal scute area, breadth at middle - 2a 

Inguinal scute area, length at middle 2f 

Inguinal scute area, breadth at middle 2^ 

The sacral vertebrae, represented in Figs. 11, 12, Plate XIX, are of pro- 
portionately greater length than in Baena. The first one is nearly as long as 
it is broad ; and the second is half as long again as the former, and is equal 
ill this respect to its breadth. 

The anterior articulation of the first sacral centrum forms a decided cup- 
like depression, and not merely a transverse concavity like that in the snap- 
per. The second sacral centrum is prolonged to an unusual degree beyond 



17^ 

the neural arch. It ends iu a flat, roughened articular surface, as if iulendrd 
for tlie conjunction of another vertebra entering into the constitution of llu; 
sacrum. The neural arches of the sacral vertebrie are proportionately higher 
than in the snapper, and they appear to have articulated movably with each 
other by zygapophyses alone. 

The diapophyses are about equally developed with those in the snapper. 
The neural arch is not co-ossified with the centrum ; nor are the pleurapophyses 
co-ossified with either. 

Measurements of the sacral vertebaa are as follows : 

Liues. 

Length of the sacrum inferiorly 18 

Length of first sacral centrum 7 

Breadth of first sacral vertebra, with diapophyses 9 

Length -of second sacral centrum 11 

Breadth of secoud sacral vertebra, witli diapophyses 10^ 

Height of first sacral vertebra to end of spinous process 13 

Height of anterior articulation of first sacral centrum ■. 5 

Breadth of anterior articulation of first sacral centrum 5 

An isolated vertebra, from Henry's Fork of Green River, looks as if it 
might be the first sacral of Chisternon undatum. The body is little more than 
half the length of that of the last sacral above described, but its anterior 
articular surface agrees in size, form, and roughness with the posterior sur- 
face of the last sacral centrum just mentioned. .The pleurapophyses have 
about the same degree of develo])ment as in the snapper. 

Fig. 10, Plate XVI, represents a caudal vertebra, obtained by Dr. Carter 
near Lodge-Pole Trail. In construction it resembles the caudals of the 
snapper, the centrum, as in this, lieing opisthocoelian, or having a cup behind 
and a ball in front. The proportions of the vertebra accord best with the 
more anterior caudals of the snapper, but its transverse processes are as small 
as in the terminal, caudals of the latter. Perhaps it may belong to Chister- 
non, but the opinion is conjectural. If the former isolated vertebra belongs 
to Chisternon, it is doubtful whether this second one does. 

Fig. 7, Plate XVI, represents an isolated ilium of a turtle, found at Grizzly 
Buttes by Dr. Carter. It resembles in its form that of a snapper, but is more 
robust in proportion to its length. The inner surface at the up])er extremity 
is flat and longitudinally striated, but is devoid of the fossa existing in the 
.snapper. The length of the bone is 3^ inches; the width of its upper end 
!| of an inch ; the width at the lower end is 17 liues. From the form ol'llie 



174 

bone I would suspect that it belonged to Chisternon, rather than to either 
Emys Carteri or Baptemys wyomingensis. 

HYBEMYS. 

Hybemys akenarius. 

Two Httle specimens, obtained by Professor Hayden, in the Tertiary for- 
mation of Little Sandy Creek, Wyoming, appear to indicate a previously 
undescribed turtle, to which the above name was given. They consist of 

m 

a detached marginal bone, and a fragment of a costal plate of a species 
about the size of the common spotted turtle, Emys guttata. The bones are 
unusually thick in proportion to their breadth, compared with those of ordi- 
nary recent Emydes. Their surface is smooth and strongly marked by the 
lines of separation of the scute areas. The costal ridge on the interior of the 
costal plate is scarcely perceptible ; the costal capitulum is rather stouter 
than in Emydes. 

The marginal plate represented in Fig. 9, Plate XV, is especially remark- 
able, and it is upon its peculiarity that the genus is inferred. It would appear 
to correspond with the ninth of the series, and has the same form as in the 
corresponding plate of ordinary Emydes. The outer portion of the upper 
surface, strongly defined by the groove of the costal scute, exhibits at its fore 
and back part a half-circular boss, occupying the middle of the marginal 
scute areas. As we may safely infer the other marginals to have the same 
construction, it follows that the margin of the carapace is ornamented with a 
circle of hemispherical bosses, each of which is crossed by the sutures of the 
marginal bones. 

ANOSTEIRA. 

Anosteira oenata. 

Among the many remains of turtles from the Bridger Tertiary formation, 
submitted to my examination from time to time, by Dr. Carter and Professor 
Hayden, there were a few isolated plates of peculiar character which were 
described and referred to a genus and species under the above name. Sub- 
sequently Dr. Carter discovered many parts of a shell of the same species, 
which we have endeavored to collocate as represented in Figs. 1, 2, Plate 
XVI. 

Anosteira is a remarkable genus, very unlike any other turtle, 'previously 



175 

described, recent or extinct. The carapace and plastron, while being com- 
pletely ossified as in Testudines, Eniydes, &c., are ornamented in a manner 
only seen to the same degree in the soft-shelled turtles. True, we see some- 
thing like ornamentation of the same kind in some of the Emydes,.but in 
them the condition is comparatively feeble. The osseous shell also appears 
to be devoid of the usual outlines more or less sti'ongly expressed of the in- 
vesting scutes. A few of the plates exhibit obscure lines, but I am uncertain 
as to whether they accord with the areas of the scutes. 

The outline of the carapace is broadly cordiform and somewhat resembles 
that of the ordinary sea-turtles, but is not acute posteriorly as in these, being 
obtuse as in the Bmydes. The prominence of the carapace is moderate as in 
the less elevated forms of the latter. It is uniformly convex, except that it 
is acutely carinated in the median line posteriorly. 

The margin of the carapace anteriorly is rather obtuse, but laterally and 
posteriorly is quite sharp. It is broadly and concavely notched in front ; the 
first pair of marginal plates being the most prominent portions anteriorly. 
Antero-laterally it is slightly concave, and from this position posteriorly is 
uniformly convex. 

The plastron with its bridges is flat, and is intermediate in its relative pro- 
portions with that of the snappers and Emydes. The bridges articulate with 
the carapace by gomphosis, as seen in Fig. 2. They join the marginal plates 
from the fifth to the eighth inclusive. The extremities of the plastron are 
botli broken away in the specimen. 

The vertebral plates of the carapace are narrow coffin-shaped. Those an- 
terior are nearly level ; those posterior are acutely carinated. 

The costal plates within exhibit no costal elevation, but are quite level, as 
represented in Fig. 3. The costal capitula are unusually broad but thin. 

The inner surface of the nuchal plate at the posterior border presents a 
pair of round articular processes for conjunction with the contiguous vertebra. 

The upper surface of the carapace is ornate with rugosities. These are 
obsolete on the vertebral plates. On the costal plates they appear as longi- 
tudinal, undulating, and nearly parallel ridges crossing the plates. Internally 
they are feebly developed and become more strongly marked proceeding out- 
wardly. 

On the marginal, including the nuchal and pygal plates, the rugosities arc 
finer, closer, more interrupted, and in part even granular. 



17G 

Beneatli, the rugosities of the marginal plates have a decidedly radiant 
appearance. The under surface of the marginals in advance of the axillary 
notches, and the corresponding surface of the nuchal plate, are smooth or de- 
void of the ornate rugosities. 

The pygal plate and the contiguous marginals increase in thickness from 
their free acute edge inwardly, so as to be wedge-shaped in section. The 
base of the wedge, directed toward the cavity of the shell, is strongly grooved 
in the pygal plate, and gradually less so in the contiguous marginal plates. 
The groove contributes to the general cavity of the shell. Fig. 6 represents 
a fore and aft section of the pygal plate, exhibiting the groove on its inner part. 

The plates of the plastron exhibit their ornate ridges arranged in a radiat- 
ing manner, as seen in Fig. 2, but they are less prominent than those of the 
carapace. 

The shell of the specimen of Anosteira, from which the above description 
was taken, in its entire condition, was about 5 inches in length in the median 
line and about 4^ inches in breadth. 

Figs. 4, 5, represent two anterior marginal [)lates, showing that the species 
reaches a much greater size. 

TRIONYX. 

Trionyx guttatus. 

One or more species of the soft-shelled turtles ( Trionyx) are indicated by 
an abundance of fragments of shells which have come under my notice in the 
various collections of fossils from the Bridger beds. Anything like complete 
shells appear to be rare, as the best preserved which has yet been submitted 
to my examination is the portion of a carapace i-epresented in Fig. 1, Plate 
IX. The specimen, attached to a mass of sandstone, was obtained at Church 
Buttes, near Fort Bridger, during Professor Hayden's exploration of 1868 

The osseous carapace in its entire condition is estimated to have been 
about a foot and a quarter in length, and, independently of the extension of 
the free ends of the riljs, has nearly reached that breadth. The bones range 
from three to four lines in thickness, except along the position of the costal 
ridges and near the thinner edges. 

The carapace appears to iiave had the usual composition of seven vertebral 
plates, and eight pairs of costal plates back of the nuchal plate. It was mod- ■ 
erately convex, and the posterior border in the specimen is deeply scolloped. 



177 

The vertebral plates in the specimen, consisting of part of the second, tliini, 
and itmrtli, are reversed coffin-shaped, and nearly twice as long as wide. 
Their anterior border is convex, and the posterior border concave. 

The fifth vertebral plate is smaller than the preceding, and becomes eaiTier 
narrowed from the sides toward the back end. 

The sixth plate is lozenge-shaped, about as long as it is wide, and occupies 
the space between the truncated angles of the sixth and seventh costal plates. 
The latter meet in the median line for more than half their width. 

The seventh vertebral plate is a very small lozenge-shaped bone, with a 
crucial ridge on its surface, occupying an interval produced by the truncation 
of the contiguous angles of the seventh and eighth pairs of costal plates. 

The costal plates, from the fourth to the sixth inclusive, are nearly of the 
same width internally, and they successively become more widened out- 
wardly. The seventh costal plate is rather wider at the extremities tlian 
intermediately. The last costal plates are nearly as wide fore and aft as from 
within outwardly. 

The surface of the carapace is sculptured tor the most part with broad, 
rounded, and isolated concave pits resembling the impression of rain-drops on 
a soft surface. Only near the outer border of the costal plates, where these 
are preserved, do the pits become more or less confluent, usually in twos and 
threes. The reticular ridges bounding the pits are broad and low, and often 
as wide as the included pits. 

Measurements of the specimen are as follows : 

Lines. 

Length of tliird vertebral plate . . 23 

Width of third vei'tebral plate iu front 7 

Width of third vertebral plate behind 12 

Length of fourth vertebral ijlate 20J 

Width of fourth vertebral plate in front 7^ 

Width of fourth vertebral plate behind 10;^ 

Length of fifth vertebral plate , I'Ji 

Width of fifth vertebral plate in front 7 

Width of iifth vertebral plate at middle Sft 

Length of sixth vertebral plate - 10 

Width of sixth vertebral plate at anterior third 10 

Length of seventh vertebral plate 5| 

Width of seventh vertebral plate at middle 5 

Width of fourth costal plate fore and aft at inner part 23 

Width of fifth costal plate fore and aft at inner part 22 

Width of sixth co.stal plate fore and aft at inner part 21 

Width of seventh costal plate fore and aft at inner part IDJ 

23 G 



178 

Liucs. 

Width of eighth costal plate fore and aft at inner part ... 18 

Length of sixth costal plate at middle 58 

Length of seventh costal plate at middle ... 41 

Length of eighth costal plate at middle 22 

Many fragments, l)oth of the carapace and plastron of soft-shelled turtles, 
collected during Professor Hayden's expedition of 1870, and subsequently 
bj' Drs. Carter and Corson at various localities in the vicinity of Fort Bridger, 
appear to be referable to the same species as the above. 

A specimen consisting of the right half of a nuchal plate, with an attached 
piece of a first costal, derived from the same locality as the specimen above 
described, belonged to an animal about the same size. The width of the 
scabrous portion of the nuchal plate in its complete condition was about 6f 
inches; its fore and aft extent 1^ inches. The sculpturing of the surface is 
more interrupted or broken than in the specimen specially referred to Trionyx 
guttatus. The reticular ridges ^.re narrower and sharper, and exhil)it a dis- 
position to rise in points at their intersection. 

A specimen consisting of an outer portion of an intermediate costal plate 
measures 3f inches wide, and is 5 lines thick. The reticulation of its sur- 
liicc is unbroken, but otherwise it reseml)les that of the nuchal plate just 
described. 

Teionyx uintaensis. 

During my stay at Fort Bridger, in a trip to Dry Creek, Major R. S. 
La Motte discovered the nearly complete carapace of a Trionyx, which he 
presented to the Academy of Natural Sciences of Philadelphia. The sjieci- 
men is represented in Fig. 1, Plate XXIX, one-half the natural size. On first 
view I supposed it to belong to the same species as the former, but compar- 
ison of the specimen with that of Fig. 1 of Plate IV leads to the belief that 
it pertains to a different one. 

The carapace is about 16J inches long and 16 inches broad, so that its 
proportions are reversed from those in our living Trionyx muticus. It is 
about as convex as in the latter, and appears to have been slightly depressed 
along the position of the vertebral plates, judging from that portion of the 
shell back of the fiith costal plates, as in advance of this the specimen has • 
been crushed inwardly. The fore and back part of the carapace is truncated, 
as in T. miiflcys. The posterior truncation, slightly sinuous, extends the 
width of the last two pairs of costal plates. In T. gtittalus the corresponding 



179 



border occupied 1)} the latter is convex, and exliibits three deep .siiuiosilies — 
the middle one and the one on each side, as seen in Fig. 1, Plate IX. 

Eiglit })airs of costal plates succeed the nuchal plate. The second, fifth, 
and sixth pairs expand considerably outward, more especially the last of 
these. The others are of more uniform breadth. 

The specimen possesses only six vertebral plates. Of these, the first is the 
longest and widest. Its fore border is convex, and nearly in a line with the 
suture between the nuchal and first pair of costal plates. The lateral borders 
diverge to the back angles, -which are truncated to join the second pair of 
costal plates. 

- The' second and third vertebral plates are nearly equal in size, and are 
reversed coffin-shaped. The fourth plate is smaller, and oblong (pmdrate, 
with convex borders. The fifth plate is obverse coffin-shaped, shorter, but 
wider than the former. "^Fhe sixth vertebral plate has not more than half its 
usual development. It is pentagonal shield-like, and is included between the 
angles of the fifth and sixth costal plates. 

The posterior half of the sixth costal plates, and those succeeding them, 
unite in the median line by a tortuous suture. 

The surface of the carapace presents a nearly uniform reticular aspect 
and the thickness of the bones is of the usual proportion. 

The measurements of the specimen are as follows : 



Space occupied by the six vertebral plates 

Breadth of uucljal plate 

Extent of uuclial plate in median line 

Breadth together of seventh pair of costal plates 
Breadth together of eighth pair of costal plates . 



Inches. 



m 

34 



Breadth. 




First vertebi'al plate . . . 
Secoud vertebral plate . 
■ Third vertebral plate . . 
Fourth vertebral plate 
Fifth vertebral plate . . . 
Sixth vertebral plate . . . 



180 



Leugtli. 



Depth 
iutcrnally. 



Depth 
externally. 



First costal plate . . 
Sceoiul costal i)late- 
TLird costal plate . . 
Foiirtli costal [)late. 
Fifth costal plate . . . 
Sixth costal plate . . . 
Seveuth costal plate 



I Itches. 
G 
8 
8 

8 
8 

7 



Lines. 

29 
22 
21 
23 

18 
16 



Lines. 
32 
38 
26 
26 
33 
42 
21 



REMAINS OF TRIONYX OF UNDETERMINED SPECIES. 

Small tVagineuts of Trioiiyx shells, from the Bridger Tertiary strata, exhib- 
iting a ditrereiit kind of surface-marking or sculpture from that of the specimens 
referred to the preceding species, probably indicate others, or, perhaps, differ- 
ent genera. . 

A specimen found l>y Dr. Carter at Dry Creek, and represented in Fig. 11, 
Plate XVI, is an outer fragment of a costal plate. It is not pitted as in 
Tronyx guttatus, but is crossed obliquely by coarse ridges with the intervals 
occupied by a lattice of narrower ridges. Probably the specimen may belong 
to a species of Anosteira. 

Another fragment of a costal plate, from Little Sandy Creek, is represented 
in Fig. 12 of the same plate. This specimen differs from the former in being 
crossed by widely separated ridges, with the intervals finely pitted. 

Other specimens exhibit slight differences from the foregoing and from 
those of Trionyx gutlatus, but are too imperfect to enable one to form any 
idea of their relationship. 

• Order Lacertilia. 

The lizards have vertebrae with concavo-convex bodies, and have the teeth 
co-ossified with the jaws. The skin is furnished with horny or bony scales. 
True lizards, allied to the existing monitors, iguanas, and chameleons, appear 
to have been abundant and of varied character in the ancient Wyoming fauna. 
Few remains of these animals, described in the succeeding pages, have been 
submitted to my inspection, but Professor Marsh has indicated and briefly 
described twenty-one species- of five extinct genera from fossils obtained 
by him from the Bridger beds. 



181 

SANIVA. 

Saniva ensidens. 

An extinct lizard, to whicli the above name has l)cen applied, is indicated 
by some remains discovered during Professor Ilaydcn's exploration of 1870, 
near Granger, Wyoming. The remains consist of portions of a skeleton, in a 
fragmentary condition, imbedded in an indurated ash-colored marl rock. The 
bones are black, and the hollows of the long Ijones, including the ribs and 
phalanges, are occupied with crystalline calcite. 

The remains belong to a lacertian about the size of the existing monitor 
of the Nile, to which it appears to have been closely related. The bones 
indicate a robust body, a long tail, and limbs with long toes. 

The vertebrae resemble those of the Nilotic monitor in form and propor- 
tions, and like them possess no zygosphenal articulation. 

A pair of dorsal vertebrae are represented in Fig. 15, Plate XV. Tlie body 
is J an inch long inferiorly, and measures f of an inch l^etween the dia- 
pophyses. The ball and socket extremities are twice the breadth of the height. 
The ball measures 4 lines in breadth and 2 lines in height. The neural arch 
laterally at the zygapophyses is nearly 8 lines long. 

An anterior caudal has the same length as the dorsals, but is narrower. 
The ball is of less width, but the same height. The hypopophyses for the 
chevron are quite prominent, and are situated a short distance in advance of 
the ball, as in the monitor. 

A small detached tooth, imbedded in the same mass, in proximity to some 
small skull-fragments, presents the form and constitution of those of the moni- 
tors. It is represented in Fig. 35, Plate XXVII, magnified eight diameters. 
The length of the tooth is about IJ lines; its breadth, f of a line; and its 
thickness, J a line. It is compressed conical, feebly curved niwardly and back- 
ward, sharp-pointed, has abruptly impressed trenchant borders, and is smooth 
and shining. It is hollow, and has thick walls. The transverse section of 
the base is rhomboidally oval, with acute poles. 

In breaking off portions of the rock containing the bones aljove described, 
there was exposed what appears to be the anterior extremity of a maxillary 
containing the remains of six teeth. The fragment is 4 lines long and 1^- 
lines deep. The teeth are pleurodont in character, but appear different in 
ibrm from tlie isolated tooth above indicated, and have more resemblance in 
shape to those of the iguana. The specimen appears so small in ils propor- 



182 

tions with the other bones, that it leads to the suspicion that it may not belong 
to the same skeleton. 

No scales were ibund in association with the bones in the same mass of 
rock. 

The name Saniwa, according to Professor Hayden, is nsed by one of the 
Indian tribes of the Upper Missonri for a rock-lizard-. 

Saniva major. 

Several fragments, discovered by Dr. Carter near the Lodge-Pole Trail, 
crossin'g Dry Creek, would appear to indicate a larger species of Saniva. The 
specimens are of a greenish hue and somewhat smooth or water-worn, and 
were derived from a green sandstone stratum. 

One of the fossils consists of the distal extremity of a humerus, repre- 
sented in Fig. 14, Plate XV. It resembles in general aspect the correspond- 
ing portion of the humerus of the monitor, but the shaft is proportionately 
more robust, and not so much narrowed toward the middle. It is occupied 
by a large medullary cavity with compact walls, as in the humerus of a bird. 
The internal epicondyle appears less prominent than in the monitor, in con- 
sequence of the less degree of contraction of the shaft. The external epicon- 
dyle does not reach upward to more than half the relative extent it does in 
the monitor, and it is not perforated. The ulnar eminence is prominent in 
front, but projects below to a less degree than the radial capitellum. 

The breadth of the bone at the epicondyles is f of an inch. The greater 
diameter or breadth of the shaft at the broken end is 3| lines ; the short 
diameter is 2^ lines. 

Another of the fossils consists of a pair of dorsal vertebras, represented in 
Figs. 36, 37, Plate XXVII. They agree in all respects with the two vertebrae 
referred to the former species, except that they are considerably larger. 

The bodies of the vertebrae inferiorly measure 7| lines in length and lOi 
lines in width between the diapophyses. The ball measures 5 lines in In-eadth 
and 3 hnes in height. The neural arch laterally at the zygapophyses is 10 
lines in length 

GLYPTOSAURUS. 

Professor Marsh has described, in the American Journal of Science and 
Arts for 1871, another genus of extinct lizards, under the above name, from 
remains obtained in the liridger Tertiary. He observes that "the head was 



183 

covered willi large osseous shields symmetrically iirniiigcd and highly orna- 
mented. Other i)ai-ts of the body, especially the ventral region, were pi-o- 
tected by rectangular, ornamented shields, united to each other Ijy suture. 
The teeth are pleurodont, and are round with obtuse summits. The dorsal 
and caudal vertebra? have the same general form as those of Varauus, but show 
traces of a zygospheue articulation. 

Professor Marsh indicates eight species, maiidy liiunded on diii'erences in 
the position, form, and ornamentation of the dermal osseous shields and the 
form of the teeth. 

Dr. Carter has submitted to my examination a number of specimens col- 
lected by him at Grizzly Buttes, which in part or whole are attributable to 
the same genus, and mostly to the species named Glijptosaurus ocellatus. 

Several of the dermal shields from the trunk of the body are represented 
in Figs. 13 to 15, Plate XVI, and several of the cranial shields in Figs. 16, 17, 
of the same plate, all magnified two diameters. 

The dermal shields of the trunk are oblong cpiadrate, with the longer mar- 
gins thick and roughened for sutural conjunction with one another. The ex- 
tremities thin out for imbrication. The anterior exti-emity, which is over- 
lapped by the shield in advance, extends a third or more of the length of the 
plate, and is smooth. The posterior two-thirds or less of the shields are orna- 
mented on their free surface with nnnided knobs or tubercles, closely arranged 
in more or less concentric rows. 

The cranial shields are from foui- to six sided, and proi)ortionately of greater 
thickness than the former. All their margins are roughened for sutural at- 
tachment together, and their free surface is ornamented in the same manner 
as the shields of the trunk. 

Accompanying the specimens of dermal shields above described, there are 
several detached vertebrae. One of the specimens is a dorsal vertebra re- 
sembling those of Saniva, but somewhat smaller, and, like them, presents no 
zygosphene articulation. It may probably belong to that genus. The other 
specimen is an intermediate caudal vertebra of the same proportions of length 
and breadth as in Saniva, but the ball and socket articulation is as high as it 
is wide. It has no zygophene articulation, and the hypopophyses for the 
chevron are immediately beneath the ball of the body. The length of the 
latter interiorly is 2| lines. - 



184 

CHAMELEO. 

Chameleo peistinus. 

A small fragment of a lower jaw with teeth, discovered by Dr. Carter in 
the Bridger Tertiary formation, is represented in Figs. 38, 39, Plate XXVII, 
magnified three diameters. In every respect it agrees with the correspond- 
ing part of tlie jaw of tlie living chameleons, but^ indicates a much larger 
species. In a space of 5 lines the alveolar border is occupied by eight teeth 
successively increasing in size from Ijefore backward. 

The teeth are laterally compressed conical, with the borders in front and 
behind somewhat extended and acute, and at the base produced into a minute 
denticle. Externally the bases of the teeth are separated by perpendicular 
furrows descending on the face of the jaw to the position of a finely perforate 
horizontal line. Beneath the bases of the teeth internally there is a wider 
and more conspicuous horizontal and perforated groove. Below this, toward 
the rounded base of the jaw, the usual Meckelian groove is situated. The 
outer face of the jaw exhibits two vasculo-neural foramina. The depth of 
the lower jaw from the point of the last tooth of the specimen is 2 J lines. 

FISHES. 

The remains of fishes in the Bridger beds are not so abundant as one might 
have supposed from the nature of their composition and the conditions of their 
origin. Nevertheless, it is probable that fishes were abundant in genera, 
species, and individuals in the great Uintah Lake and its tributaries, whose de- 
posits form the Bridger beds. The same circumstances which removed the 
less coherent parts of the skeleton from the interior of the many turtles, and 
likewise scattered the bones of these and of the multitude of other reptiles 
and of mammals, no doubt served to destroy the more delicate strncture of 
the fishes and to distribute their hard parts through the mud. It is probable 
that future explorations may lead to the discovery of some strata of the Bridger 
beds in which well-preserved forms of fishes may exist like those found in the 
shales of the deeper beds of Green River. 

The remains of fishes from the Bridger beds, which, with few exceptions, 
were found by Dr. Carter and submitted to my examination, consist mainly of 
smoothly enameled ganoid scales, a few isolated specimens of vertebral centra, 
portions of spinous raj^s, and fragments of jaws with tcetli. My means of 
comparison of these specimens with the skeletons of recent fishes are ex- 



185 

ceediiigly meager, but they indicate forms wliich generally appear to he most 
nearly related with our mud-tishes, (^Aniia,) and the gars, {Lepidosteus,) 

Professor Marsh (Proceedings of the Academy of Natural Sciences of 
Philadelphia, 1871, p. 105) has already noticed specimens from the same 
locality, which he refers to two species of Amia about the size of A. calva, 
and two species of Lepidosteus about the same .size as the modern gar-pike. 

AMIA. 

Amia (Peotamia) uintaensis. 

A number of specimens, discovered by Dr. Carter on the l:)uttes about ten 
miles from Dry Creek Canon, indicate a large fish related with the modern 
Amia, but exhibiting sufficient peculiarity to pertain to a different genus, for 
which the name of Protamia has been proposed. 

Figs. 1, 2, Plate XXXII, represent one of the best-preserved specimens, a 
vertebral centrum from the fore part of the dorsal series. Its breadth is con- 
siderably gi-eater in proportion with its length than in Amia;' it is more 
prominent below ; has a different transverse outline; has shorter parapophyses, 
which also spring from a higher position at the sides, and the bottom of the 
articular cones is situated considerably above the centre. 

The centrum is nearly tour times the width and three times the height of 
its length. It is slightly curved from side to side with the convexity directed 
forward. It is widest at the upper third, opposite the origin of the para- 
pophyses, and is shortest at the sides intermediately. 

The articular cones have their bottom considerably above the center, and 
are more minutely perforate for the notochord than in Amia. 

The sides of the centrum are concave between the pi'ominent articular 
margins, and slant in a nearly straight line to the ridges defining the narrow 
inferior surface. The latter is concave, and the lateral ridges are obtuse, and 
excavated in an oblong shallow fossa at their fore part. 

The upper part of the centrum is transversely convex between the jtara- 
pophyses. The articular fossas for the contiguous neural arches, as in Amia, 
are in the form of the figure of 8, and their internal prominent borders form 
the lateral limits of the bottom of the neural canal. 

The parapophyses are short, stout processes projecting above the middle 
of the centrum from its widest part, and on a line with the bottom ol tlic 
articular cones. 
24 G 



186 
The measurements of the specimen are as follows: 

Liues. 

Lcngtli of ceuti'um iiifeiioily 5. C 

Height of ceutrum auteriorly 15. 5 

Width of centrum iu line with the parapophyses 20. 

Another specimen from the same locality as the preceding is represented 
in Figs. 3, 4, Plate XXXII. It appears to be the centrum of an atlas, and 
may probably belong to the same species as the former, though, judging from 
its difterent aspect, to a ditfereut individual. 

The centrum is transversely oval and slightly curved, with the convexity 
of the curve directed forward Its breadth is two and a half times the height, 
and over live times the length. 

The anterior sui-face is nearly flat and somewhat uneven, and just above 
the center is depressed into a concave pit about one-fifth the diameter of the 
centrum. The posterior surface presents the usual cone with its l)ot- 
tom just above the center. 

The sides of the centrum are concave between the articular borders, and 
bear no trace of parapophyses. The lower part is more flat, and presents a 
shallow fossa on each side of a median concavity. The fossae for the neural 
arch are quite prominent at their contiguous borders. 

The measurements of the specimen are as follows : 

Lines. 

Length of centrum inferiorly 4 

Height of centrum anteriorly 14 

Breadth of ceutrum at middle 22 

A third specimen, from the same locality, less well preserved, resembles 
the first one, and belonged apparently to a somewhat smaller individual. Its 
parapophyses barely project beyond the sides, and are hollowed at the end. 
The ridges defining the inferior surface from the concave sides are barely 
excavated. 

Its measurements are as follows : 

Lines. 

Length of centrum inferiorly 5. 5 

Height of centrum auteriorly 15. 5 

Breadth of ceutrum at the upper third 18. 25 

A series of three specimens, witii a portion of another, from the same 
locality as the preceding, appear to correspond with the anterior vertebrae of 
Araia from the second to the fifth inclusive. The fragment resembles the 
lateral half of the atlas above described, but is bi-concave. The other speci- 
mens resemble the first and third ones above descril)e(l in the form of the 



187 

centrum. In 'the third vertebra the parapopliyses arc higli up, as in the iirst- 
described specimen. In the succeeding two they spring Ironi near the middle 
of the sides of the centrum. 

The measurements of the second cervical are as follows : 

LineB- 

Length of centrum inferiorly 4 

Depth of centrum anteriorly i;j 

Breadth of centrum at middle 20 

. The measurements of the fifth vertebra are as follows : 

Lines. 

Length of centrum inferiorly 3. 6 

Depth of centrum anteriorly . 12. 

Breadth of centrum at middle, ou line with parapophyaes 17. 

A series of three posterior dorsal centra, from the same locality as the 
preceding specimens, perhaps belong to the same species, but, from their 
appearance, most probably to another individual. They are somewhat dis- 
torted from pressure, and appear in the original condition closely to have 
resembled corresponding vertebrae of Amia^calva, but are nearly three times 
the breadth, and scarcely twice the length. 

The three specimens together, represented in Fig. 5, measure 16 lines in 
length. 

The anterior of the three presents the following measurements : 

Lines. 

Length of centrum inferiorly 5 

Depth of centrum anteriorly 11 

Breadth of centrum inferiorly, opposite the diapophyses 14 

A specimen from Dry Creek, consisting of a mutilated basi-occipital, about 
the size of that of the alHgator-gar, ditfers considerably as well as from that 
of the mud-fish. It is represented in Figs. 6, 6", and may perhaps belong to 
Protamia. 

The articular conical cup has its acute margin scolloped, as seen in Fig. 6. 
The deep median groove on the under part of the bone in Amia and Lepi- 
dosteus reaches the articular margin, but in the fossil, stops the fourth of an 
inch short of it. On each side of the bone at the articular margin correspontiing 
with the lateral notch there is a conspicuous fossa not seen in the genera just 
named. In advance of the fossa on each side of the median groove there is 
a broad, slanting, flat surface, longitudinally ridged, of which there is likewise 
no exact counterpart in Lepidosteus, but appears to correspond with a smooth 
surface occupying the same position in Amia. 



188 

Amia (Peotamia) media. • 

Figs. 7 to 9 represent a vertebral centrum, obtained at the junction of the 
Sandy and Grreen Rivers, during Professor Hayden's expedition of 1870. In 
its form and proportions it resemJiles a centrum from near the fore part of 
the dorsal series of Amia calva, but pertainetl to a species double the size. 
It presents several peculiarities which render it probable that it belongs to a 
related genus. The sides of the centrum ai-e less contracted than in Amia, 
and the pair of ridges beneath are substituted by a pair of oval pits. The 
parapophyses project transversely just above the middle, and are very short. 

The measurements of the specimen are as follows: 

Lines. 

Leugtb of ceutrum inferiorly 5. 5 

Height of centrum 10. 2 

Breadth of centrum 1.3. 

Figs. 10, 11 represent a vertebral centrum, found by Dr. Carter on Dry 
Creek. It resembles a centrum of Amia calva from the back of the dorsal 
series, but is double the size. It presents beneath a pair of grooved ridges, 
as in A. calva. 

The specimen measures as follows : 

Lines. 

Length of centrum inferioi'ly 4. 

Height of centrum 7. G 

Breadth of centrum 8. 6 

Amia (Protamia) gracilis. 

Figs. 23, 24, Plate XXXII, represent a vertebral centrum found by Dr. 
Cai'ter, together with a number of ganoid scales, opposite the second cross- 
ing of Henry's Fork of Green River. The centrum has a different color from 
the scales, and clearly did not belong to the same fish. It is from near the 
middle of the dorsal series, and pertained to a smaller species than Amia 
calva The two ridges beneath the centra of the latter are substituted by 
^two oblong fossae. 

The measurements of the specimen are as follows: 

Lines. 

Length of vertebral centrum inferiorly 1. 8 

Height of vertebral centrum 3. -t 

Breadth of vertebral centrum 3. 8 



189 

HYPAMIA. 

Hypamia elegans. 

Figs. 19 to 22, Plate XXXII, represent a vertebral centrum, found hy Dr. 
Carter on Dry Creek. It is from near the middle of the dorsal series, and 
evidently indicates a genus distinct from but nearly related with Amia. As 
in this, the cenlrum is short in proportion with its breadth, and it presents 
sutural impressions for a contiguous pair of neural arches. The articular 
cups have their bottom central and minutely perforate. The sides below the 
parapophyses are concave, and converge to a median prominence, which is 
excavated into a pair of fossas, separated only by a linear partition. The 
l)arapopliyses ai'e cylindroid and comparatively short. 

The measurements of the specimen are as follows : 

Lines. 

Length of centrum iuferiorly 2. li 

Depth of centrum anteriorly (i. 5 

Breadth of centrum anteriorly 7. (5 

Breadth of centrum, including parapophyses 8. 5 

The specimen indicates a species about one-third larger than Amia calva. 

LEPIDOSTEUS. 
Lepidosteus ateox. 

During Professor Hayden's expedition of 1870, James Stevenson collected 
a number of remains of tishesat the junction of Big Sandy and Green Rivers, 
Wyoming. The specimens consist of isolated vertebral centra, ganoid scales, 
and portions of jaws with teeth, all of a black hue. Among them are several 
vertebrae indicating an extinct species of gar larger than the existing alliga- 
tor-gar, Lepidosteus ferox. 

Figs. 14, 15, Plate XXXII, represent the centrum of a vertebra from a 
position in advance of the middle of the dorsal series. The length of the 
centrum is not greater than the breadth. The extremities are hexaliedral in 
outline. The under surface is flat, and ornate with longitudinal and somewhat 
reticular wrinkles. The sides beneath the pai-apophyses are impressed into 
a deep fossa. The neurapophyses are likewise impressed at the sides with a 
deep fossn, and a second deep pit occupies a position just behind and above 
tlu! parapophyses. These appear rather narrower than in the alligator-gar, 
atnl are less anterior in [tosition. 



190 
The measurements of the specimen are as follows : 

Lines. 

Length of centrum iuferiorly . . 8. 6 

Breadth of ceutrum posteriorly 8. G 

Height of ceutrum i)osteriorly — , CO 

Another specunen, consisting of a caudal centrum, perhaps belongs to the 
same species. It has about the same length as the preceding, and is hexa- 
gonal in outline at the ends. Its sides present a strong longitudinal ridge 
separating a deep fossa below from another above. 

The measurements of the specimen are as follows : 

Lines. 

Length of centrum interiorly 8. 4 

Breadth of centrum posteriorly 4. 4 

Height of centrum ijosteriorly 4. 8 

Lepidosteus ? 

Accompanying the preceding specimens there are two vertebrae of another 
species of Lepidosteus. One of them is a posterior dorsal centrum, and is 
represented in Figs. IG, 17. It is about as long as the corresponding centra 
of the gar-pike, Lepidosteus osseus, but is ^jroportionately broader and more 
robust. Its articular ends are hexahedral, with the upper and lower borders 
slightly emarginate. The lower surface of the centrum is nearly flat, nearly 
level, contracted at its anterior third, and deeply grooved along the middle. 
It is bounded by ridges defining it? from the deeply impressed sides. 

The other specimen is the centrum of a caudal nearly as long as the former, 
but narrower in proportion with its difference of position in the series. 

The measurements of the specimens are as follows : 

Lines. 

Length of dorsal centrum iuferiorly 5. 4 

Length of caudal centrum iuferiorly , 5. 

Breadth of dorsal centrum posteriorly 5.4 

Breadth of caudal centrum posteriorly 3. 

Height of dorsal centrum posteriorly 4.2 

Height of caudal centrum posteriorly 3. 2 

These specimens may, perhaps, belong to one of the species indicated by 
Professor Marsh. 

Figs. 27 to 30 represent several ganoid scales, accompanying the preceding 
specimens, which probably pertain to the smaller of the two Lepidostei. 
They are covered \\itli perfectly smooth, shining ganoine without markings. 

Fig. 25 represents a fragment of the fore part of the right ramus of the 
lower jaw accompanying the former specimens. Its construction is similar 



191 

to the corresponding part in the alligator-gar, but is proportionately not so 
tliick or rolnist near the sympiiysial end. The lower surface is reticulated 
with round meshes, and the ridges of the net are ornate with shining trans- 
lucent tubercles. 

The dental groove exhibits the remains of a row of large teeth, of which 
one retained exhibits the same cliaracter as those of the living gars. The 
outer edge of the groove was also furnished with minute teeth, but the inner 
edge exhibits no trace of these organs. 

Lepidosteus simplex. 

Some remains of a Lepidosteus, together with some fragments of a turtle- 
shell, were collected near Washakie Station, Wyoming, by James Stevenson, 
during Professor Hayden's exi^loration of 1870. The remains of the Lepidos- 
teus consist of a mutilated basi-occipital and three succeeding vertebral cen- 
tra, together with several small jaw-fragments and a number of large ganoid 
scales. 

The basi-occipital and vertebral centra, represented in Fig. 18, Plate 
XXXII, resemble in form and proportions those of alligator-gar, but an; 
smaller. 

A tooth, represented in Fig. 26, contained in one of the jaw-fragments 
agrees in character with the larger teeth of living gars. The outer edge of 
the same jaw-fragment is furnished with smaller and more curved teeth of 
the same kind. 

Figs. 31, 32 represent two lozenge-shaped scales of less In'cadth but thicker 
than those of the alligator-gar. The enamel surface is flat, smooth, and 
highly polished, and exhibits no markings except one or several minute puncta 
near the center. 

Fig. 33 represents a similar scale, which appears to be traversed lijre and 
aft by a canal communicating by a sliort cleft with the outer surface. The 
cleft is directed backward, and is protected by an angular elevation of the 
anterior border. 

Fig. 34 represents another scale of a different form, probal)!y from I he 
median line of the back. 

The measurements of the basi-occipital and vcrteljral centra are as follows : 

Liues. 

Breadth of the articulation of the basi-occipital 10. 

Height irom lower groove to ed^e of occipital foi'amen "). 

Length of first vertebral ceutriiui -1. 



192 

Lines. 

Breadth of first vertebral centrum 10. 

LcDgtli of secoud vertebral ceutrum 4. 4 

Breadth of secoud vertebral centrum 7. 6 

Length of third vertebral centrum 5. 

Breadth of third vertebral ceutrum 6. 8 

A number of large ganoid scales, of the same character as the preceding, 
were collected in a sandstone stratum on Little Sandy Creek, during Pro- 
fessor Hayden's expedition of 1870. Several of these selected from the collec- 
tion are represented in Figs. 35 to 38. 

A number of similar scales were obtained by Dr. Carter in the vicinity 
of Fort Bridger. Figs. 39 to 42 represent several of the scales selected from 
the collection. 

Fig. 43 represents a scale of a Lepidosteus found in association with the 
large saber-like canines described in the preceding pages, and supposed to 
belong to Uintatherium. 

Lepidosteus notabilis. 

A vertebral centrum partially imbedded in a yellowish sandstone contain- 
ing casts of shells was obtained near Washakie, Wyoming, during Professor 
Hayden's exploration of 1870. 

The centrum is represented in Figs. 12, 13, and appears to indicate a fish 
related with Lepidosteus, but probably of a ditfereilt genus. It pertains to 
an anterior dorsal, and is about the size of a corresponding centrum of the 
alligator-gar, but has the parapophyses much shorter. The centrum also 
differs in shape from those of the alligator-gar. The lower surface is broad 
and flat, and is marked with longitudinal curved and furcate ridges. The sides 
are perpendicular and depressed in a deep fossa beneath the parapophyses 
In tiie alligator-gar the sides slant outwardly from the lower surface. 

The posterior end of the centrum of the fossil is four-sided, with the 
widest border above and convex, the shortest below and straight, and the 
lateral borders slanting with a slight sigmoid course. 

The short parapophyses project from the upper part of the centrum nearly 
from the middle. 

The measurements of the specimen are as follows : 

Lines 

Length of centrum inferiorly 8 

Height of centrum posteriorly 9 

Breadth of ceutrum at upper part 10 

Breadth of ceutvum at lower part- 6 

Breadth of ceutrum, iuchuling parapophyses 13 



193 
PIMELODUS. 

PiMELODUS ANTIQUUS. 

Among the fossil-fish lemaiiis of Professor tiaydcn's colleotioii from Uic 
junction of the Big Sandy and Green Rivers, there are a iiumher of fragments 
of pectoral spines and a few jaw-fragments of a species of cat-tish. 

The pectoral spines, of which two fragments are represented in Figs. 44, 
45, Plate XXXII, are like those of our living cat-fisii. A fragment compris- 
ing about two-thirds of the symphysial portion of a dcntary bone. Fig. 46, re- 
sembles the same in the recent cat-fish, and, as in it, was covered with a l)n)a(l 
card-like surface of teeth. The breadth of the dentary surfiice near the sym- 
physis is 3^ lines. The pectoral spines have ranged from an inch to upward 
of 2 inches in length. The size of the specie was from a foot to 18 inclies. 

PHAREODUS. 

PlIAEEODUS ACUTUS. 

Accompanying the remains of gars and cat-fish, from i\\{- junction of lh<' 
Big Sandy and Green Rivers, there are many fragments of jaw-l)oncs and 
others with teeth, evidently not belonging to either of those genera of fislies. 
They also present sufficient peculiarity to render it jirobable that they may 
not belong in the same family with Amia, and therefore jiroljably not to thc! 
closely allied genera supposed to be indicated by the vertebral specimens 
described in the preceding pages. The means of comparison at my command 
are too scanty to enable me to determine the affinities of the fish to which 
the fossils pertain. 

Figs. 49, 50, Plate XXXII represent two of the best preserved and more 
characteristic of the specimens, consisting of fragments of" dentary bones. 
These are proportionately deeper and stronger than in Amia. Tliey su])])oi'f 
a single row of long teeth at the border, and possess no patch of smaller 
teeth internally such as exist in Amia. The teeth are cylindro-conical, witii 
their somewhat thickened liases close together and firmly co-ossified with the 
jaw. Tlieir shaft is straight and not curved as in Amia, l)ut thc sharp coni- 
cal apex is bent inwardly. 

Figs. 47, 48 represent fragments of prcmaxillaries. In these the iccWi 
are of the same character as in thc dentary bones, Ijul are less beni at tlic 
tips. 



•JF, 



) c. 



104 



Fig. 51 represents what 1 suppose to be a fragment of a maxillary ol' the 
same fish. It is provided with teeth as in Amia, Salmo, and some other 
genera. 

Associated with the specimens of the character above described thei-e are, 
a number of others, consisting of small fragments of bones with close patches 
of short conical teeth, like the vomerine and other similar patches of teeth of 
Amia. 

The dentary fragment of Fig. 49 contains the remains of a dozen teeth in 
the space of 11 lines. The specimen of Fig. 50 contained thirteen teeth within 
a space of 10 lines from the symphysis. Of the retained teeth the last is the 
longest, and measures nearly 3 hnes. The others are about 2J lines in length. 
The premaxillary fragment of Fig. 48 contained seven teeth in a space of as 
many lines. The first tooth is the longest, and measures 2f lines. In 
the other fragment of Fig. 47, ten teeth occupied a space of 8J lines. 

The genus supposed to be indicated by the specimens has been named from 
the light-house-like form of the teeth. 

EEMAINS OF FISHES FROM THE SHALES OF GREEN RIVER, WYOMING. 

In Professor Hayden's Preliminary Report on the Geology of Wyoming 
for 1870, p. 142, the author remarks that soon after leaving Rock Springs 
Station, on the Union Pacific Railroad, the Green River group is seen on the 
bluff hills on either side of the road to the entrance of Bitter Creek into 
Green River. In the valley of the latter remarkal)le sections of strata 
are exposed to view. The group he calls the Green River shales, because the 
strata are composed of thin layers, varying in thickness from that of a knife-blade 
to several inches. The rocks all have a grayish-buff color on exposure, some- 
times with bands of dark brown. These dai-ker bands are saturated with a 
bituminous matter which renders them combustible. 

About two miles west of Rock Springs Station there is an excavation on 
the railroad which has been called the Petrified Fish Cut, on account of the 
thousands of beautiful and perfect fossil-fishes which are found on the surface 
of the thin shales, sometimes a dozen or more on an area of a square foot. 
Remains of insects und aquatic plants are also found in the shales, and in one 
instance a well-preserved portion of a feather of a bird was discovered. 

A large collection of fossil-fishes from the Petrified Fish Cut, obtained I)y 
Professor Ilaydcn in 1;)70, was subinilted to Professor Cope, who has described 
tiie different forms in tlir i('[»orl al)ove mentioned. 



195 

The first of the fossil-fishes of the Green River shales was discovered by 
the late Dr. John Evans as early as 185G, and was submitted to the examina- 
tion of the writer. Several specimens, both of the bufi'-colored and dark 
bituminous shales, containing fossil-fishes, have been presented to me by 
Judge W. A. Carter and Dr. J. Van A. Carter, of Fort Bridger, Wyoming. 

Professor Cope describes seven species, including one of those described 
by me, from the Green River shales. Two are named Clupea himulis and 
C. pusilla, and a third Osteoglossum encaustum. The others are referred to 
two extinct genera with the names of Asineops squamifrons and A. viridensis, 
Erismatopterus Rickseckeri and E. levatus. 

CLUPEA. 

Clupea humilis. 

The species was originally described in the Proceedings of the Academy 
of Natural Sciences of Philadelphia for 1856, page 256. It was indicated 
from a specimen consisting of an impression of a nearly complete fish in a 
l)iece of shale, which looks like one-half of a rounded, water-worn fragnuMit. 
The fossil was found by Dr. Evans on Green River, and was stated by him 
to have been derived from the Tertiary rocks of that locality. The fish is 
represented in Fig. 1, Plate XVII, of the natural size. It has the ordinary 
form of living species of herring, and presents the characters of the genus. 

This small herring in its total length has measured about 3^ inches. The 
back is slightly arched, and the dorsal fin is situated just in advance of the 
middle. The ventral border is strongly arched, and is rather abruptly nar- 
rowed from the anus. The ventral fins are placed beneath ihc back of the 
middle of the dorsal fin. The head is pointed. The tail is deeply forked, 
and its pedicle is rather narrow. 

The number of vertebras appears to be about thirty-four, of which at least 
twenty are dorsal, tlie remainder caudal. The notochord appears to liave 
extended continuously through the perfoi'ated vertebral bodies. 

The depth of the l)ody at the fore part of the dorsal fin is four and a luilf 
times less than the length. The length of the head slightly exceeds the 
depth of the body. The eyes are large. 

The pectoral fins are destroyed, but their connection with tli(^ body was 
just below the position of the operculum. Tlie ventral liiis ('(nilaiii seven 
rays. 



196 

The dorsal' fin appears to have had thirteen rays, of which the second was 
the longest, and from which the others gradually decreased. The anal fin 
contains fourteen rays. The caudal fin between its two extreme outer and 
longest rays, inclusive of these, appears to possess twenty rays. 

The ventral carinated spines are twenty-five. Accessory ribs project from 
the vertebrae and ordinary ribs in the usual manner in the herrings. 

Measurements of the specimen are as follows : 

Lines. 

Total length of tbe fish io 

Length to commeucement of the tail 34 

Depth of body in front of dorsal fin 10 

Deiith at anus 

Length of the head lOi 

Depth of the head 8:^ 

Length of the tail lo" 

Depth of iiedicle of the tail 4 

Distance from snout to couiinenceiuent of dorsal tin 17 

Distance from snout to anus 27 

Clupea alta. 

A slab of shale obtained from the so-called " Petrified Fish Cut,'' and sub- 
mitted to my examination, contains ten herrings, in which the bones and 
scales are preserved, and stained of a dark-brown hue. The vertebrae, where 
broken, exhibit the position of a continuous notochord occupied by hyaline 
chalcedony that looks like the original substance of the latter itself The 
most complete and largest of the fossil-fishes is represented of the natural 
size in Fig. 2, Plate XVII. 

These fishes appear to ])elong to a different species of herring from the 
former, especially distinguished hy the greater proportionate depth of the 
body and the more arched dorsal l)order. In most other essential character's 
the two appear to agree. It has the same number of vertebras and of ventral 
carinated spines. The fins also, so far as can be determined, appear to con- 
tain the same number of rays. 

The other specimens on the slab, though smaller, exhil)it the same, or 
nearly the same, proportionate depth of the body. 

The measurements of the specimen figured are as follows: 

Liiu^s. 

Total length of the fish bO 

Length to commencement of tail 38 

Depth of body in front of dorsal tin Hi 



197 

Lines. 

Depth at anus 91 

Length of head 12 

Depth of head 10^ 

Length of tail 11 

Depth of iiedicle of tail 5 

Distance from snout to coiuinencemeut of dorsal fin 20J 

Distance from snout to anus 31 



DESCRIPTION OF REMAINS OF MAMMALS FROM THE TERTIARY 
FORMATION OF SWEETWATER RIVER, WYOMING. 



A small collection of fossils, consisting of the remains of mammals, was 
obtained, during Professor Hayden's expedition of 1870, on Sweetwater 
River, eighteen miles west of Devil's Gate, Wyoming. 

Professor Hayden, in his Preliminary Report of the Geological Snrvey 
of Wyoming, 1871, page 32, in relation to the locality whence the fossils 
were obtained, makes the following remarks : " Near Cloven Peak, fifteen 
miles west of Devil's Gate, there are some bluff-banks on the south side 
of the Sweetwater, about one hundred feet high, which indicate the exist- 
ence of quite modern Tertiary beds, like those on the Niobrara River. 
They are composed of indurated sauds and marls of a light-gray or cream 
color, and are in appearance precisely like those seen on the Laramie River, 
and many other places, which I have usually regarded as of the Pliocene age. 
Still farther to the westward are numerous exposures of these beds, which 
are weathered into the usual fortification-like forms, and scattered around 
their base are large numbers of remains of extinct mammals and turtles, 
apjjarently identical with those found on the Niobrara. They occur in the 
same beautiful state of preservation.'' 

Professor Hayden's view of the age of the formation is confirmed l)y the 
zoological character of the fossils, which are nearly related with those from 
the Pliocene Tertiary sands of the Niobrara River, and are, without doul)t, 
of a much more recent date than those of the Bridger beds. 

The specimens sul^mitted to my examination consist of fragments of jaws 
with teeth, portions of the larger limb-bones, small bones of the feet, and a 
few mutilated vertebrae. Most of them pertain to a species of Merycochoerus, 
an animal nearly related to Oreodon. A few apparently belonged to a smaller 
species, and several to a small equine animal. The others remain undeter- 
mined for want of ready means of comparison. 

The fossils are all isolated specimens, which were picked up from the sur- 
fixce of the ground. Usually they are perfectly free from adherent matrix. 
They are white in appearance, and resemble recent bleached bones. They 



199 

have losl (licir l)onc-cartilage, and arc linnl and hriUlc, Uiouii^li not (rialilc 
Tliey are nut in the least degree water- worn, and present no appearance ol" 
having been submitted to great pressure, as is so Irequently the case with the 
ossils from the Cretaceous and Eocene formations of neighboring localities. 

MAMMALIA. 

Ordiir Ruminantia. 
MERYCOCHCERUS. 

Merycociicerus rusticus. 

The genus above named was originally characterized from some remains, 
discovered by Professor Hayden during Lieutenant Warren's expedition of 
1857, in a bed of dull, fine-grained grit, on the head-waters of the Niobrara 
River, near Fort Laramie, Nebraska. 

Merycoclioerus pertains to the same family as Oreodon, a genus character- 
ized from a profusion of remains from tlie Miocene Tertiary deposit of the 
Mauvaises Terres of Wliite River, Dakota. The general construction and 
form of the skull appear to be nearly the same, and such, also, is the case 
with the number, constitution, and relative position of the teeth. There are, 
however, certain peculiarities distinguishing the two genera. 

The molar teeth of Oreodon have, comparatively with those of most genera 
of existing ruminants, short crowns as in the deer; and, as in this, at matu- 
rity they are all inserted alone by fangs. In Merycochosrus the crowns of 
the molars are proportionately longer, and in the mature condition of the ani- 
mal, while the anterior ones were fully protruded, the posterior ones, though 
in functional position, were only partially protruded, and continued to advance 
as they were worn away. The difference between the two genera, Oreodon 
and Merycochoerus, in respect to tlie comparative length of the molar crowns, 
is like that existing between the molars of the deer and the ox, but not to 
the same degree. While the condition of the teeth of Oreodon corresponds to 
that of the deer, those of Merycochoerus rather hold an intermediate condi- 
tion to those of the deer and the ox. 

In Oreodon, when the last of the molar series was fully protruded so as to 
be inserted by the fangs alone, the anterior molars might still be in a condi- 
tion to exhibit very conspicuously the anatomical characters of tlieir triturat- 
ing surfaces, as displayed in Plate VII of tlie Extinct Mammalian Fauna of 



200 

Dakota and Nebraska. In Merycochoerus, on tlie othei- band, lieforc tlie 
crown of tbe last molar was fully protruded, ab'eady tbe anatomical characters 
of the triturating surfixces of those in advance were, to some extent, destroyed ; 
and in the case of tbe first true molar completely obliterated, in this state pre- 
senting simply a broad dentinal surface bordered with enamel. This condi- 
tion is represented in the Fig. 3, of Plate X, of the same work just mentioned, 
though in this case the specimen belonged to an individual past maturity, and 
the last molar is fully protruded. 

Another distinctive character in the teeth of Oreodon and Merycochoerus is 
expressed in the less degree of transverse symmetry of the crowns of the 
premolars in the latter. In Oreodon tlieir various measurements are more 
uniform, and the summits of the principal constituent lobes of their crowns are 
nearly or quite median, and they nearly retained this relative position as the 
teeth were worn away. In Merycochoerus the length and fore and aft diame- 
ter of the crown exceed the transverse diameter except in the last upper one; 
and the summits of the lobes of the premolars, especially in the upper ones, 
are more or less in advance of the middle of tlie crowns, and they likewise 
retained this relative position as the teeth were worn. 

In the original description of Merycochoerus, its distinction from Oreodon 
was mainly founded, on peculiarities of the skull; the differences in the teeth 
above noted, especially those in the proportionate length of the crowns of the 
molars, and their relative mode of protrusion, were not recognized. This 
want of appreciation of the distinctive characters of the teeth of the two gen- 
era arose from the observations having been made on the jaw-specimens of 
Merycochoerus advanced beyond maturity, in which all the teeth were fully 
protruded, and in this condition did not strikingly differ from those of Oreodon. 

A number of other fossils, discovered by Professor Hayden in the Pliocene 
sands of the Niobrara Valley, and described by the writer at the same time 
as those referred to Merycochoerus, from the difference in the proportionate 
length of the molar teeth in comparison with those of Oreodon, were referred 
to another genus with the name of Merychyus. In the same manner this 
was supposed to differ from the Merycochoerus; and though subsequently, in 
the preparation of the " Extinct Mammalian Fauna of Dakota and Nebraska," 
it was suspected that these two genera migiit prove to be the same, it was 
not until the present moment the suspicion appeared to be confirmed. From 
present observations and reflection, I am under the impression that Oreodon 



201 

ami Merycochoerus are two quite distinct though closely allied genera, of 
which the latter is geologically the later, and, perhaps, the successor by evolu- 
tion from the former. Merychyus would appear to be the same as Meryco- 
chojrus, and the fossils which had been referred to it belong to the same geo- 
logical horizon. 

Of the specimens originally attributed to Merychyus major and M. medius, 
too little of the corresponding parts were preserved in such a condition as to 
enable us to make a comparison of the upjier jaw and face with the same 
parts in Merycochoerus to ascertain how far they are like one another. The 
position of the infra-orbital foramen, which appears to be nearly or quite con- 
stant in a species, or varies but slightly in several species of a genus, in the 
jaw-specimen referred to Merychyus major is placed above the last premolar. 
It occupies the same position in Merychyus elegans ; and in the up[)er jaw of 
a young animal, referred to Merychyus Jiiedlus, it is placed aljove the last 
temporary premolar, therefore agreeing in position with that in tlie adults of 
the other two species. In Merycochcej-us proprius the position of the foramen 
is further back, al)ove the interval of the first and second molars, and this is, 
also, its position in the upper jaw of the Sweetwater species named Meryco- 
choerus rusticus. 

This difference of position is probably related with adiiference in the shape 
of the face, which in ]\Ierycochoerus is rather abruptly narrowed in advance 
of the zygomata, as in the hog. The face of Merychyus I suspect rather to 
1)0 more like that of Oreodon, nari'owing graduallj' forward from the position 
of the orijits and zygomata, as in the peccary. 

Admitting the three genera, Oreodon, Merycochoerus, and Merychyus, their 
distinctive characters, so far as ascertained from the materials at command, 
would appeal' to be as follows : 

Oreodon. — Molar teeth with short crowns, as in the deer; and, as in 
this, at maturity inserted by fangs. Anterior premolars straight, with the 
diameters nearly equal, and with their points median or nearly so. Face 
gradually convergent, conical. Infra-orbital arch narrow or of moderate 
depth; gradually declining upon the side of the face. Infra-orbital foramen 
small and situated al)ove the tliird premolar. Nasal orifice nearly as wide as 
high, and situated immediately above the incisive alveolar border, as usual in 
most animals. Premaxillaries and maxillaries remaining distinct from one 
anotlier. Incisive foramina of moderate size. 
•2G G 



202 

Merycociicerus. — Crowns of the molars proportionately longer than in 
Oreodon, and protruding gradually as they were worn away ; the anterior 
having their sculptured triturating surface obliterated before the posterior are 
fully protruded. Anterior premolars with the length and breadth exceeding the 
width, and the upper ones inclining posteriorly, and with their points in advance 
of the middle. Facial cone aliruptly narrowed in advance of the orbits. 
Infra-orbital arches deep and rapidly declining on the face. Orbits smaller 
and more externally situated than in Oreodon. Infra-orbital foramen above 
the interval of the tirst and second molars. Nasal orifice situated far above 
the alveolar border, as in the tapir, and commencing below as an angular 
notch of the premaxillaries, which are firmly co-ossified together and with 
the maxillaries. Incisive foramen large. 

Meeychyus. — Teeth as in Merycochoerus. Facial cone intermediate in 
character to the latter and Oreodon (?) Infra- orbital foramen situated above 
the last premolar, or in a position intermediate to that of Oreodon and 
Merycoehcerus. 

The more characteristic of the remains of Merycochajrus, from the Sweet- 
water River, consist of fragments of jaws with teeth from perhaps a half 
dozen individuals. One of the specimens consists of the greater part of an 
upper jaw, represented in Figs. 1, 2, Plate III, accompanied with a portion 
of the lower jaw, represented in Fig. 3 of tlie same plate. 

The face of Merycochoerus, as indicated by the upper-jaw specimen just 
mentioned, would appear to difter in a remarkable manner from that of the 
closely allied genus Oreodon. In the species to which the name of Merij- 
cochcerus rusticus has been given, and which probably is the same as Mery- 
chyus medius, the face is narrowed in the same abrupt manner in advance of 
the orbits as in Merycochcems proprius. It is, however, more convergent than 
in the latter, or is proportionately less widened at the extremity. 

The relation of the orbits and zygomata to the fore part of the face in 
Oreodon is more like the condition in the peccary; in Merycochoerus more 
like that in the hog. 

The side of the face in If. rusticus between the position of the 
orbit and the prominence produced by the canine, and above the alveolar 
ridge, is deeply concave, even more so proportionately than in the hog. In 
M. propr'ms, it is not depressed in this manner, so that the side of 
the face in the corresponding position is nearly vertical, and the large infra- 



203 

orl)ital foramen opens forward on this vertical surface. In M. rusticiis^ I lie 
infra-orbital foramen is also large, and occupies a corresponding position, \n\i 
is situated in the concavity of the side of the face, so that the surface of the 
alveolar border curves outwardly and downward from it. 

The front of the snout or fore part of the upper jaw resembles in its con- 
struction the same part in the tapir more than that of Oi-eodon, but, as in the 
latter, it barely projects beyond the position of the canine alveoli. The pre- 
maxillaries are completely co-ossified with each other and with the maxillaries. 

Viewed at the side, the fore part of the upper jaw is convex forward and 
downward, as in the tapir. Viewed in front, (Fig. 2, Plate III,) it presents a 
long slope, narrow above, widening below, depressed toward tiie median line, 
and bounded laterally by the convex curved prominences of the canine 
alveoli. About 1 J inches above the alveolar margin the nasal orifice com- 
mences in an angular notch as in the tapir, but proportionately less narrow. 

Behind the position of this nasal notch, bordered by thickened ridges 
ascending in a convergent manner from the canine alveoli, are the lateral con- 
cavities of the face before mentioned. 

The upper part of the face being broken away, we can form no just idea 
of its character. If constructed as in Oreodon, by the conjunction of the 
maxillaries along the course of the nasals, it would appear to be exceedingly 
narrow, even less than half the width at the alveolar border. It would appear 
as if the construction might be somewhat similar to that in tlic tapir, so that 
the maxillaries bounded a large nasal aperture overhung by the nasals. 

The infra-orbital arch is nearly twice the depth it is in Oreodon, and resem- 
bles in its proportions that of the hog. Its outer surface is nearly vertical or 
slopes slightly outward, and is nearly plane or slightly depressed. The ante- 
rior zygomatic root is an unusually prominent process of tlie maxillary. Its 
sutui'e of conjunction with the malar descends nearly on a line with the an- 
terior border of the orbit. The latter is smaller, and is situated more exter- 
nally than in Oreodon. 

Tiie roof of the mouth is moderately concave, and the incisive foramen, 
apparently, is proj^ortionately as large as in the tapir. 

The lower jaw of Merycochcerus is like that of Oreodon, and, as in this and 
all living ruminants, has the rami united by suture. 

The mental foramen, like the infra-orbital foramen, is proportionately larger 
than in Oreodon. Perhai)s this difference in the size of the ii)ranii:)a, tog<;ther 



204 

with the other peculiarities of the face, may indicate that Merycochoerus was 
provided with large prehensile lips, or probably a short proboscis. 

As in Oreodon, the dental series of the upper jaw consists of 3 incisors, 1 
canine, 4 premolars, and 3 molars ; of the lower jaw, 4 incisors, 1 canine, 3 
premolars, and 3 molars. 

In both jaws of Merycochoerus, as in Oreodon, the teeth form nearly closed 
rows. The largest interval is between the canine and first premolar of the 
upjier jaw, to accommodate the lower canine, which in all the Oreodont family 
occupies a position behind the upper one. 

A last upper incisor, retained in the upper-jaw specimen of Merycochoerus 
rusticus, resembles in its form and relative size to the others the correspond- 
ing tooth in Merychyus elegans. 

In a fragment of a lower jaw represented in Fig. 5, Plate VII, and retain- 
ing most of the incisors, the lateral one is observed to be much larger in re- 
lation with the others than in Oreodon. Its crown, viewed in front, is nearly 
ovoid in outline. Its borders are acute and meet in a rounded point. The 
outer surface is convex. The inner surface, considerably shorter, is bounded 
by a basal ridge. The intervening incisors, about half the size of the outer 
one, successively but slightly decrease. Their crown is more truncate at the 
summit, and the internal basal ridge is stronger. The large lateral incisor is 
to be viewed as a modified canine in its relation with this tooth as present in 
animals usually. 

The canines of Merycochognis in all respects are like those of Oreodon. 
As in this genus, the lower ones are to be viewed as modified first premolars, 
assuming the form and function of canine teeth, but still holding in relation to 
the other teeth the ordinary position of the former. 

The crowns of the premolars of M. rusticus in their earlier state are con- 
siderably longer proportionately than those of Oreodon, and by the time they 
became wholly protruded they were so much worn as to have the peculiar 
construction of their triturating surface obliterated. 

The crowns of the upper premolars, except the last one, have a backward 
inclination, successively increasing from the third to the first. The points 
of these teeth occupy the anterior third of the crown in the earUer stage, 
and at a late period become so advanced as to appear to form the anterior 
corner of the crown. In Oreodon the corresponding teeth are nearly or quite 
straight, and the summit of the crown is median, and continues so as the 



205 

teeth are worn away. The difTerences mentioned — that is to sa}', (he back- 
ward inclination of the crowns of the premolars and the more advanced 
position of their points in Merycochoerus — wouhl appear to be due to a com- 
parative shortening of tlie face and a less consequent space ti)r the dev(dop- 
ment of the teeth. 

Tlie same ditierences which have been mentioned as existing between tlie 
premolars of Merycochceriis rusticus and Oreodon are also obvious in Mery- 
chyus elegans. The same may be said also of the third upper premolar in 
the fossil referred to MerycJiyus major, except that in this the crown of tlie 
tooth is proportionately not so long as in Merycochoirus. rusticus, and was less 
worn when fully protruded. 

In Merycochcerus rusticus the outer face of the upper premolars is convex 
longitudinally, but concave transversely; the lateral borders having a consider- 
able degree of pi'ominence. In M. proprius and Merychyus major they are like- 
wise concave and bordered l)y a strong basal ridge which is absent in Mery- 
cochoirus rusticus. In Merychyus elegans the outer lace of the upper pre- 
molars is convex transversely as well as longitudinally, and, as in the latter, is 
devoid of a basal ridge. 

In a small fragment of an upper jaw of M. rusticus, containing the second 
and third premolars, represented in Figs. 3, 4, Plate VII, the crowns are com- 
paratively but little worn and retain the characters of the triturating surface. 
These teeth are of less breadth in proportion to their thickness than in M. 
proprius, and in this respect are more like the corresponding teeth of Oreodon. 
Their outer part forms a strong curve from the ends of the fangs to the point 
of the crown, of which about one-fourth externally remains unprotruded, 
while it is fully protruded internally. The point of the crown is at the 
anterior third, and externally it appears to be continuous as part ol" the an- 
terior projecting border of tlie crown. The inner portion of the crown ex- 
hil)its three deep recesses inclosed l)y prominent loop-like folds. The pos- 
terior larger recess is separated fi-om the anterior smaller pair by a ridge 
dividing the inner part of the outer or principal lobe of the crown. A basal 
ridge festoons the posterior internal loop of the third premolar, but docs not 
exist in the second. The teeth are worn olTin a slope on the postero-internal 
lace of the principal lobe of the crown. 



206 

These teetli are sufficiently like the corresponding tooth in the jaw-speci- 
men of Merychyus major to render it proljable that this animal may belong to 
the same genus as the former. 

The last upper premolar of McrycoclicBrus rusticus is like that of M. pro- 
jjyius. 

The superior molars, the inferior premolars and molars, are so closely like 
those of Merychyus elegans, that they may be considered as their magnified 
representatives. 

Fig. 1, Plate VII, represents a series of upper molars in a specimen in 
which the last one has not more than two-thirds protruded. A view of the 
outer part of this last molar is introduced in the representation of the upper 
jaw in Fig. 1, Plate III, so as to complete the series of upper molar teeth. 
In the first molar the anterior crescentic enamel pit is observed to be com- 
pletely obliterated, and the posterior one nearly so. In the back two molars 
the inuer faces of the internal lobes are decidedly concave longitudinally. 

In Fig. 6, Plate VII, we have a presentation of the first and second 
upper molars of Merycochoerus proprius introduced for comparison. Tlie 
specimen is from the head-waters of the Niobrara River, in the vicinity of 
Fort Laramie. 

Fig. 2, of the same plate, represents the last premolar and the molar of 
the temporary series of M. rusticus. The molar is like those of the perma- 
nent set ; the premolar resembles the former modified by having the anterior 
lobes, especially the inner one, proportionately less well developed. 

In a small fragment of an upper jaw of another young animal, in which the 
temporary molars were retained and the first permanent moJar had protruded, 
the maxillary presents a different appearance from that in the adult. The 
surfaces above and below the position of the ridge produced by the malar 
process are almost at a right angle to each other. The upper surface slopes 
forward and outward from the position occupied by the orbit, and upon it 
opens the infra-orbital foramen about half an inch within the ridge separat- 
ing this sui'face from the lower one. In the progress of development from 
youth to age the angularity of the outer part of the maxillary became rounded, 
so that the surface assumed a convex instead of a nearly rectangular char- 
acter. 



207 



Measuremeuts of the iaws and teeth of M. rustlcus are as follows 



Distance from upper inei.sors to back of last molar 

Length of space occupied by upper series of molar teeth . . . 

Length of space occupied by upper premolarvS 

Length of space occupied by ui)per molars 

Breadth of upper jaw outside of canines 

Breadth of upper jaw outside of second premolars 

Breadth of upper jaw outside of second molars 

Breadth of upper jaw at inner side of infra-orbital foramina 

Breadth of face at lower margin of the orbits 

Distance from lower incisors to back of last molar 

Length of space occupied by lower series of molar teeth . . . 

Length of space occnpied by lower premolars 

Length of space occupied by lower molars 

Depth of lower jaw at symphysis 

Depth of lower jaw below last premolar - 

Depth of lower jaw below secoiul molar 

Width of condyle of lower jaw 



Liues. 



G2 

53 
2'1 
31 
22 
24 
30 
20 
55 
62 
48 
17 
31 
29 
19 
22 
19 



Diameter of upper canine 

Diameter of lower canine 

Diameter of second upper premolar 
Diameter of third upper premolar , . 
Diameter of fourth upper premolar 

Diameter of first upper molar 

Diameter of second upper molar . . 

Diameter of third upj)er molar 

Diameter of first lower premolar . . . 
Diameter of second lower premolar 
Diameter of third lower premolar. . 

Diameter of first lower molar 

Diameter of second lower molar . . . 
Diameter of third lower molar 



Antero- 
posterior. 



11 



Lines. 

5 

G 
5 

SJ 
-12" 
14 

5 



Gi 

7 
10 
15.^ 



Transverse. 



Lines. 
4a 

4 
5 

^ 

10-10.} 

10^ 

23 

4i 

5 

G 



Of other bones referable to Merycochoerus rmticus, the collection contains 
the following: 

Portions of several scapulER. The glenoid cavity is oval, and mcasiurs 11 
Hnes in its short diameter, and 15 lines in its long dianjolcr, including (he 
coracoid process. 



208 

A numlier of fragments, mostly distal extremities of tibiae, of which one is 
represented in Fig. 9, Plate XX. The general construction is the same as 
in ordinary even-toed nngulates. The shaft approaching the articulation is 
three-sided, with the outer border subacute. This terminates in a triangular 
surface for junction with a filjula. The internal malleolus is comparatively 
long and pointed, and projects below the position of the anterior process of 
the tibia. The articular concavities are nearly of the same extent fore and 
aft, but the outer one is much the wider. The width of the end of the tibia 
in different specimens ranges from 13 to 14 lines, and the fore and aft diam- 
eter is 8J lines. 

Of a number of specimens of the astragalus, one is represented in Fig. 10, 
Plate XX. It is about the size of that of the peccary, but is proportionately 
wider. The outer division of the trochlea is considerably larger than the 
inner one. The" posterior articular surface for the calcaneum extends but 
little more than half the width of the bone. The length of the astragalus 
externally is 16 lines; its width at the lower tarsal articulation is 10^ lines. 

Of a number of specimens of the calcaneum, one is represented in Fig. 11. 
It is about the size of those of tlie peccary, but is more robust in its propor- 
tions. The tuber is a little shorter, but considerably thicker. A peculiarity 
of the bone is the absence of a sustentaculum tali, the usual articular surface 
of the latter being supported on a moderate expansion of tlie base of the 
tuber. The articular eminence for the fibula is but slightly prominent. 

The length of the calcaneum is 2i inches; its width at the articulation 
below the tuber is 8 lines. 

Another specimen of a calcaneum, interesting on account of its diseased 
condition, is represented in Fig. 15, Plate II. 

Merycochcerus sp *? 

Fig. 12, Plate XX, represents the distal end of the tibia, probably of a 
smaller species of Merycochcerus. The specimen was found with those 
above described. The transverse diameter of the articular end is 11 lines. 

An astragalus resembling that above described probably belongs to the 
same animal as the latter. It is lOJ lines long, and 5J lines wide. 

Order Solidungula. 

Associated with the remains of Merycochcerus, from the Sweetwater 
River, there arc several bones of a small equine animal, probably a. species 



209 

ul' llip2)anon. Cue of Uie specimens is an external cnneil'orm bone, of wliicli 
an upper view is given in Fig. 13, Plate XX. Another specimen of the same 
bone has the navicular bone co-ossified with it. A third specimen consists 
of a first ungual phalanx 17 lines long at the side, and 14^ lines wide at the 
upper extremity. 
27 G 



DESCRIPTION OF VERTEBRATE FOSSILS FROM THE TERTIARY 
FORMATION OF JOHN DAY'S RIVER, OREGON. 



Through the Smithsonian Institution, at tlie suggestion of Professor S. F. 
Baird, a collection of fossils was submitted to the examination of Ihc writer 
by Rev. Thomas Condon, of Dalles City, Oregon. 

The fossils were discovered by Mr. Condon mainly in the valley of Bridge 
Creek, a tributary of John Day's River, one of the branches of the Columbia 
River. Some additional fossils from tlie same locality were also placed in my 
hands by Professor H. S. Osborn, of La Fayette College, Easton, Pennsyl- 
vania. 

With the exception of a single turtle-bone, the fossils consist of remains of 
mammals. In general appearance and condition of preservation they resemble 
those of the Mauvaises Terres of White River, Dakota. They are nearly all 
specimens which have been found lying loose on the surface of the country, 
and are, therefore, more or less weathered, or much injured by exposure. A 
few of the fossils are imbedded in, and the cavities of others are filled with, 
a liard, compact, homogeneous rock of a bluish-gray hue. The rock ajjpears 
to be an indurated marl, and contains abundance of lime. It bears a near 
resemblance to the matrix of the fossils of the Mauvaises Terres of Dakota, 
except that it is more compact and harder. 

The zoological character of the fossils is sucli as to render it probal)le that 
the formation to which they belong is of contemporaneous age with the Te.r- 
tiary deposit of the locality just named. 

The greater number pertain to a species of Oreodon larger than any of 
those from White River, Dakota, and about the size of Merycocha'rus proprius 
of the Niobrara River, Nebraska. 

A number of the fossils appear to belong to some of the same species as 
those of the Mauvaises Terres, as Oreodon Culbertsoni, Agrioclimrus antiquus, 
and A. latifrons, Jucptomeryx Evansi, Anchltherium Bairdi, and Rhinoceros 
occidentalis. 

The collections further contain remains of a second species of Rhinoceros, 
two species of Elotherium, &c., generally too scanty or imperfect to ascertain 
positively whether they pertain to species previously characterized 



211 

A descrij)live list of tlio fossils is given l)clow : 

MAMMALIA. 

Order Ruminantia. 

OREODON. 

Okeodon Culbeetsoni. 

This species, established on a multitude of remains from the Mauvaises 
Terres of White River, Dakota, is apparently indicated by some small frag- 
ments of upper and lower jaws with teeth, which are labeled " Big Bottom 
of John Day's River." One of the best-preserved and most characteristic 
specimens consists of a jaw-fragment containing the upper last premolar 
and the molars, the latter being represented in Fig. 12, Plate VII. In all 
respects it is like the corresponding part in Oreodon Culbertsoni, from White 
River. Other specimens show a slight variation in the size of the teeth. 

Oreodon supeebus. 

Nearly twenty-five years have elapsed since the first fossil remains of 
mammals from the Tertiary foi-mations of the West were submitted to my 
examination. To the present time they have been coming to me in constant 
succession, so that I have had the op])ortunity of examining thousands of 
specimens, the collective weight of which would amount to several tons. 
From some of the first specimens brought from the Mauvaises Terres of 
White River, Dakota, after a few errors, I thought I had fixed upon well- 
marked characters distinguishing the extinct genus of hog-like ruminants, for 
which I proposed the name of Oreodon. Two species were described under 
the names of O. Culbertsoni and O. ii;nicills, mainly from a marked difference 
in size. 

Several detached crania, diifering from that of either of the species of Oreo- 
don in the possession of large inflated ear-capsules, at first attributed to a 
■peculiar genus with the name of Eucrotaphus, were subsequently referred to 
Agriochoerus, which had originally been described from jaws and teeth. Later 
this determination appeared to be confirmed by an almost complete skull in 
which the cranium agreed with the detached specimens. 

Some small fragments, and finally a complete skull, appeared to indicati; a 
third and larger species of Oreodon, to which the name of O. majur was given. 



212 

It is especially remarkal:)le for the great size of the eai--capsules compared 
with those of the other species, being proportionately quite as large as those 
in Agriochoerus. 

Of the multitude of fragments of jaws with teeth, portions of skulls, and 
more or less complete skulls of Oreodon, which I have had the opportunity of 
examining, by far the greater number are referable to the species O. Culbertsoni, 
about a twentieth to O. gracilis, and one per centum to O. major. Specimens 
exhil)it more or less variation, generally of a comparatively trifling character, 
but in some instances to such a degree as nearly to be distinctive enough for 
other species, and in some cases as nearly to remove the distinctions between 
the two species O. Culbertsoni and O. gracilis. Two specimens, presenting a 
greater extent of variation than usual, have been suspected to represent hybrids 
in the one case between O. Culbertsoni and O. gracilis, in the otiier case between 
the former and O. major. With the view that they may be specifically dis- 
tinct, they have been named O. affinis and O. hijfy-idus. 

After a number of years, aaid after having seen many hundred specimens 
referable to O. Culbertsoni, to my utter astonishment one of the last ones 
received, consisting of the greater part of a skull, while agreeing in every 
other respect with the ordinary form of O. Culbertsoni, possesses ear-capsules 
as large as those of Agriochoerus. Looking upon this specimen as represent- 
ing a species or an importaiit variety, the name of O. bullatus was applied to 
it in allusion to its large inflated ear-capsules. 

As the cranial portion of the skull of O. bullatus does not differ in size from 
the specimens originally referred to Eucrotaphus, we are now uncertain 
whether they pertained to O. bullatus or Agriochoerus. They correlate in 
size, construction, and form equally well with either. 

Some remains from the Niobrara River, Nebraska, while clearly indicating 
members of the same family as Oreodon, appeared to me to belong to two 
different genera, to which the names of Merycochoerus and Merychyus were 
given. The recent discovery of additional remains of anotlier species of 
Merycochoerus, on the Sweetwater River, Wyoming, while rendering the , 
characters of the genus more obvious, rather tend to make the genus Mery- 
chyus doubtful. 

The skull of Merycochoerus has the same general form and construction as 
that of Oreodon, and the teeth agree in number, relative position, and consti- 
tution. The crowns of the molar teeth in Oreodon are short and inserted by 



213 

fangs, as in the deer. In Merycochoerus they are longer, and protrude more 
gradually as they are worn away. The face is more abruptly prolonged in 
front of the orbits ; the infra-orbital arches are proportionately of much greater 
depth; and the infra-orbital foramina situated much further back. While the 
fore part of the upper jaw of Oreodon is constructed in the more ordinary 
manner of many animals — suilline pachyderms, carnivora, &c. — that of Mery- 
cochoerus is more like that of the tapir. 

Merychyus, so fixr as known, is intermediate in character witli Oreodon and 
Merycochoerus. Its molar teeth are like those of the latter ; its face appears 
not to be so abruptly narrowed; and the infra-orbital foramina hold an inter- 
mediate position. 

Another member of the oreodont family, from a formation probably of 
equivalent age to that which has yielded the remains of the Oreodons, has been 
named Leptauchenia. Its molar teeth agree in character with those of Mery- 
cochoerus and Merychyus, but are more strongly folded internally in the case 
of the lower ones, externally in the case of the upper ones. The face is more 
like that of Oreodon ; has the infra-orbital foramina in the same relative posi- 
tion, but has large unossificd spaces at the upper part of the face. 

Oreodon superhus, the name which appears at the head of this chapter, was 
applied to a species, indicated more recently than any of the preceding, from 
specimens belonging to Mr. Condon's collection of Oregon fossils. The species 
exhibits characters which make it somewhat peculiar, and place it in a position 
intermediate to the White River Oreodons and the genus Merycochoerus. It 
is exemplified by a number of specimens, among which is the mutilated skull, 
represented, one-half the natural size, in Fig. 1, Plate I. Other specimens, 
consisting of detached mutilated crania, portions of others, and fragments of 
jaws and teeth, pertain to half a dozen or more individuals. 

The skull of Oreodon superhus is about the size of that of Merycocharus 
proprius. In form, proportions, and constitution, and in the number, relative 
position, and construction of the teeth, it nearly resembles the other known 
species of the genus from the Mauvaises Terres of White River, Dakota. 

The cranium proper is a magnified likeness of that of Oreodon Culbertsoni 
or O. ?n(iJor, and more especially agrees with the latter in the possession of 
large inflated ear-capsules. It presents the same kind of variation in different 
specimens observed in O. Culbertsoni. In most of the specimens the tempo- 
ral surfaces slope from the sagittal crest with a slight sigmoid curve. In one 



214 

specimen the parietal surface is deeply depressed on each side of the sagittal 
crest. In another specimen a pair of well-marked grooves follow the course of 
the fore part of the squamous suture, one in front, tlie other behind it. In all 
the specimens the front groove is more or less distinct; in some of them the 
back groove is bai'ely perceptible. 

The auditory capsules are ovoidal, with the greater diameter fore and aft, 
and the length exceeding the widtli. They extend from the paramastoid 
process forward to the middle line of the glenoid articular surface, and project 
below the level of this for half their length. 

The face of Orcodon superhus differs from that of the other species of the 
genus more than it does among these. It especially differs in the position of 
the infra-orbital foramen, and in the great proportionate depth of the infra- 
orbital arch. In the other known species of Oreodon the infra-orbital fora- 
men occupies a position above the third premolar. In O. superbus it is placed 
above the last premolar, as in Merychyus. In Merycochoerus it is placed fur- 
ther back over the interval of the first- and second true molars. The infra- 
orbital arch is proportionately as deep as in Merycochoerus, and like it presents 
a broad, nearly flat surface, extending forward below the position of the lach- 
rymal fossa. The latter is relatively shallow. The forehead is more flat than 
is usual in Oreodon Culbertsoni. The anterior nasal orifice is like that in other 
species of the genus. 

The teeth of Oreodon superhus, so far as we have had the opportunity of 
examining them, appear to agree in all respects witli those of the other known 
species. 

Fig. 16, Plate II, represents a fragment of the lower jaw, natural size, con- 
taining the premolars and the fii'st molar. A view of the triturating surfaces 
of the premolars is given in Fig. 9, Plate VII. 

Figs. 7, 8, Plate VII, represent a first molar, part of the second, and the 
last molar from a lower-jaw specimen. 

Fig. 10, of the same plate, represents a facial specimen, with a view of the 
forehead, one-half the natural size. 

Measurements obtained from several specimens of portions of skulls of 
Oreodon superbus arc as follows : 

Estimated length of skull, approximating 14 incbes. 



215 



Breadth of forehead between orbits on line with supra-orbital 

ioramiua 

Length of face from orbit to lateral nasal notch , 

Height of face on line with the second true molar 

Depth of orbital entrance 

Transverse diameter of the same 

Depth of infra-orbital arch 

Length of upi^er molar series, estimated at 

Antero-posterior diameter of last upper molar 

Transverse diameter of last upper molar 

Breadth of nasals together 



Liucs. 



50 
54 
48 
21 
19 
18 
70 



Lilies. 



L'l 



174 
15i 



Lines. 



50 



IG 



Measurements obtained from lower-jaw fragments detached and not per- 
taining to tlie preceding : 



Liues. 



Lines. 



Lines. 



Lines. 



Sjmce occupied by the lower molar series 

Space occupied by tire lower premolars 

Space occupied bj- the lower molars 

Depth of jaw below back of last molar 

Depth of jaw below fore part of last molar 

Depth of jaw below middle of first molar 

Depth of jaw below middle of second premolar 
Antero-posterior diameter of first premolar . . . 

Transverse diameter of .first premolar 

Antero-posterior diameter of second premolar. 

Transverse diameter of second premolar 

Antero-posterior diameter of third premolar . , 

Transverse diameter of third premolar 

Antero-posterior diameter of first molar 

Transverse diameter of first molar , 

Antero-j)osterior diameter of second molar 

Transverse diameter of second molar 

Antero-posterior diameter of third molar 

Transverse diameter of third molar 

Transverse diameter crown of lower cauine 



GO 
25 
40 



27 



41 
33 
26 

24 



10 

7 
114 

8.J 
19J 

9 



30J 



9 
10 

^ 
11 

64 



274 



31 
31 



11 



216 

LEPTOMERYX. 

Leptomeryx Evansi. 

A small ruminant, related to the musks, was originally described under the 
above name, from remains discovered by Dr. John Evans and Professor Hay- 
den in the Mauvaises Terres of White River, Dakota. 

Two small fragments of jaws, the one containing a well-preserved upper 
molar and the other a lower molar, from John Day's River, agree in all re- 
spects with the corresponding parts of Leptomeryx Evansi. 

AGRIOCHCERUS. 
Agriochcerus antiquus. Agriociicerus latifeons. 

The above genus and species were originally characterized from remains 
found in the Mauvaises Terres of Dakota. The genus is related with Oreodon, 
but exhibits peculiarities enough to regard it as pertaining to another family 
of extinct ruminating hog-like animals. 

A small fragment of an upper jaw with portion of a molar, and a few frag- 
ments of detached molars from John Day's River, appear to indicate the 
presence of both the above-mentioned species. 

Artiodactyla. 

DICOTYLES. 

DiCOTYLES PRISTINUS. 

An extinct animal about the size of and nearly allied to the living collared 
peccary, Dicotyles torquatus, is represented in the Condon collection by 
several detached lower molar teeth. These have nearly the size and consti- 
tution of those of the collared peccary, though considerably worn and there- 
fore smoother than when in a younger condition. Independently of this 
smoothness, due to age, the constituent lobes of their crowns do not present 
the wrinkled condition observed in the living peccaries. 

The last lower molar, i-epresented in Fig. 14, Phite VII, has a five-lobed 

.crown with a basal ridge in frout and externally, and also postero-internally. 

Tlie lobes of the crown are comparatively simple, or but slightly complicated 

by oifsets or folds. The penultimate molar, represented in Fig. 13, Plate VII, 

has four principal lobes to the crown, arranged as in the recent peccary. 

An upper molar, from a younger animal, perha])s, belonged to the same 



217 

species. It is more square tlian in the recent peccary, and has llie (pur con- 
stituent lobes of the crown comparatively smooth and devoid of wrinkles. 

Measurements of the specimens referred to Dicotyles pristinus are as fol- 
lows : 

Lines. 

Auteroposterior diameter of last lower molar 9 

Trausverse diameter of last lower molar 5 

Auteroposterior diameter of penultimate lower molar 7 

Trausverse diameter of peuultimato lower molar ^\ 

Autero-posterior diameter of lirst or secoud upper moJar 

Transverse diameter of first or secoud upper molar 5.J 

Professor O. C. Marsh has also described some remains of peccaries from 
the same locality, which he attributes to two species under the names of 
Dicotyles hesperius and Platygonus Condoni. The former is estimated as about 
half the bulk of the collared peccary, the latter as being about the size of 
the li0£ 



■'&• 



ELOTHERIUM. 

Elotherium imperatoe. 

Mr. Condon's collection of Oregon fossils contains portions of several teeth 
of large size, which are supposed to belong to a huge species of Elotherium, 
for which the above name is proposed. 

One of the specimens, represented in Fig. 3, Plate II, is a portion of a 
large canine tooth, from Bridge Creek. In the perfect condition the tooth 
would appear to have measured upward of 7 inches in length. The crown 
has measured about 3^ inches long, with the diameter at base antero-posteriorly 
about 22 lines, and transversely about 20 lines. The enamel is moderately 
rugose, except near the back border of the crown, where it exhibits a more 
folded or ridged appearance. The gibbous fang has been over 4 inches in 
leneth, with the fore and aft diameter about 2 inches and the transverse 
diameter 20 lines. 

Another mutilated specimen, from Bridge Creek, supposed to be an upper 
incisor, is represented in Fig. 27, Plate VII. When complete, the tooth has 
measured over 4 inches in length. The fang is long, conical, and nearly 
straight. The crown forms with its fang an obtuse bend or angle. It is 
conical, compressed from without inwardly, and has the lateral borders sub- 
acute and somewhat expanded toward the base. 
28 G 



218 

A tliii;d specimen, from John Day's River, represented in Fig. 4, Plate II, 
consists of tlie greater portion of the crown of an anterior premolar. It is 
blunted at the apex as the result of wear. When perfect and unworn it has 
measured about 1^ inches in length, about 16 lines antero-posteriorly, and 
about 9J lines in thickness. 

It is not improbable that part or the whole of the specimens pertain to the 
species named Elotherium superbum, from an isolated incisor tooth found in 
Calaveras County, California, in the same formation in which was discovered 
the specimen of a lower jaw referred to Rhinoceros hesperius. 

Solidungula. 

ANCHITHERIUM. 
Anchitherium Baiedi. 

The extinct genus of solidungulate animals, Anchitherium, was originally 
described from remains found in the middle Tertiary formation of France. 
Abundant remains of a species have also been found in the Mauvaises Terres 
of White River, Dakota, which have been described under the name of 
Anchitherium Balrdi. The Condon collection contains several specimens, 
consisting of detached molars and fragments of others, apparently of the 
same species. One of the best preserved of these, the crown of an upper 
molar, is represented in Fig. 15, Plate VII. In every respect it agrees with 
the upper molars of the Anchitherium Bairdi of White River. 

Anchitherium Condoni. 

A specimen in the Oregon collection of fossils, consisting of a small jaw- 
fragment with a mutilated molar, represented in Fig. 5, Plate II, I have 
referred to a species of Anchitherium, though several points lead me to sus- 
pect that it may belong to a different though closely allied genus. The gen- 
eral form and construction of the teeth are the same as in A. aurelianense and 
A. Bairdi. The intermediate lobes of the crown are proportionately larger, 
more distinct from the others, and more prominent than in the species just 
mentioned. A tubercle springing from the basal ridge between the antero- 
interual and antero-median lobes is obsolete in the true Anchitherium. 

The diameter of the crown in both directions is about three-fourths of an 
inch. The species was named in compliment to the Rev. Thomas Condon, 



219 

lliruiigli whose iulerch;! ia natural history most of the Oregon fossils have been 
brought to the notice of the world. 

Perissodactyla. 

LOPHIODON? 

Among the fossils from Bridge Creek, in the Condon collection, there is a 
small fragment of an upper jaw containing two molar teeth, represented in 
Fig. 1, Plate II, which proljably indicates a tapiroid animal, allied if not 
actually pertaining to the extinct genus Lophiodon. The teeth, which appear 
to be the upper back premolars, are much worn, and the last one is mutilated. 
They belonged to an animal about the size of the common American tapir, 
( Tapirus terrestris.) 

The teeth neai'ly resemble the corresponding ones, as we might suppose 
them to 1)6 in the same state of wear, of Lophiodon isselense, of the Eocene 
formation of France, as represented in Gervais's Plate XVIII, of the Zoologie 
et Paleontologie francaises ; or they would appear to bear a nearer resem- 
blance to those (A PalcRosyops paludosus of the Bridger Tertiary formation of 
Wyoming. 

The teeth are inserted with three fangs, two externally and a broader one 
internally. The crowns are widest transversely, square without, semicircular 
within. They are composed of a pair of pyramidal lobes externally and an 
internal median conical lobe embraced by a thick basal ridge. The antero- 
external lobe extends in a ridge to the fore part of the base of the inner lobe, 
and the postero-external lobe appears to have been continuous by a ridge 
with the base of the inner lobe. A thin basal ridge festoons the outer part 
of the crown. 

In the worn condition of the teeth they present a wide tract of dentine 
continuously on the outer lobes. In the penultimate premolar the tract ex- 
tends inwardly from the postero-external lobe on the inner lobe, and from 
the antero-external lobe to the base of the latter in front. In the last pre- 
molar the dentinal surface of the outer lobes extends continuously on the 
inner lobe. 

The penultimate premolar measures 8J lines antero-posteriorly, and \\\ 
lines transversely; the last premolar measured about 10 hues antero-poste- 
riorly, 11 lines traoisversely. 

The size of the specimen, and its apparent rclatiiniship with Lophiodon, 



220 

led me to suspect that it might pertain to the same animal as an isolated 
molar tooth, from the Mauvaises Torres of White River, Dakota, described 
under the name of Lopliiodon occidentaUs. 

RHINOCEROS. 

A number of fossils in the Oregon collection appear to indicate two differ- 
ent species of Rhinoceros, or perhaps the hornless form Aceratherium. One 
of them was about the size of the Rhinoceros occidentaUs of the Tertiary of 
the Mauvaises Terres of White River, Dakota, and was first supposed to 
belong to that species. A more attentive examination of its remains has led 
to the detection of several peculiarities which render it probable it may be a 
distinct species. As the specimens co-ordinate in size with the lower jaw 
from the California Tertiary, on which was founded the R. hesperius, they 
may perhaps pertain to this species ; and in this view I will so consider them. 
Of course, more ample material may confirm or refute our position, and may 
determine the fossils to indicate an animal different from 7^. occidentaUs and 
R. hesperius. 

The second species, a larger animal, intermediate in size to the latter ones, 
and the R. crassus of the Niobrara Pliocene Tertiary, has been distinguished 
with the name of R. pcmficus. 

Rhinoceros hesperius? 

The fossils of the Condon collection, attributed with some probability to 
this species, consist of a mutilated portion of an upper jaw an isolated upper 
molar, and a lower-jaw fragment containing one entire molar. 

The upper-jaw specimen contains portions of the fangs of the molars, of 
which there were seven, occupying a space of about 7^ inches, or about 
equal to that in Rhinoceros occidentaUs. 

The anterior extremity of the space included by the zygoma extends to a 
line with the interval of the second and third molars; in R. occidentaUs it 
extends only to a line with the back part of the last molar. 

The infra-orbital foramen is large, and occupies a position alcove the second 
premolar; in R. occidentaU's it is over the third premolar. 

Tlie upper molar, the last of the series, represented in Fig. 8, Plate II, has 
nearly the size and form of that of R. occidentaUs. As in tliis, the crown 
consists of a pair of lobes diverging inward from the antero-cxternal corner. 



221 

A strong bulge iirqjecls from the middle of the anterior lol:)c into the valley 
of the crown, which is not so well developed in It. occidentalis, and a second 
bulge at the bottom of the valley is absent in the latter. The basal ridge is 
stronger in front, and internally at the entrance of the valley of the crown it 
forms two conspicuous, rounded tubercles not seen in a corresponding posi- 
tion in R. occidentalis. The presence of these tubercles, however, is, perhaps, 
merely an individual peculiarity. The tooth measures 15 lines antero-poste- 
riorly and internally, and is estimated to have been 19 lines transversely. 

The lower-jaw fragment, containing a molar, represented in Fig. 9, Plate 
II, exhibits nothing peculiar distinguishing it from the corresponding part 
either of R. occidentalis or R. hesperius. 

Rhinoceros pacifictis. 

The fossil specimens indicative of the second species of rhinoceros from 
the Oregon Tertiary consist of a mutilated right side of the upper jaw with 
portions of fangs of the molars, except of the first premolar, and several iso- 
lated molar teeth. 

The specimens indicate a species larger than the preceding, but not reach- 
ing Rhinoceros crassus of the Niobrara Tertiary, which was about the size of 
the existing India rhinoceros. 

The upper-jaw specimen retains portions of the fangs of six molar teeth, 
counting from behind. The space occupied by the back two premolars and 
the molars is estimated at nearly 7^ inches ; that occupied by the true molars 
at rather more than 5 inches. 

The fore part of the zygomatic space is on a line with the fore part of the 
last molar tooth. 

Fig. 6, Plate II, represents an upper molar which is supposed to belong to 
this species. The specimen is broken at its back part, and is labeled "Alkali 
Flat." The crown at the fore part measures 21 lines in diameter, and is esti- 
mated to have measured IJ inches antero-posteriorly. The bottom of the 
crown is embraced with a strong basal ridge, which is strongest anteriorly 
and internally. The inner lobes expand inwardly, but do not bulge in the 
abrupt manner posteriorly to the same degree that they do in R. occidentalis. 
The bottom of the oblique valley of the crown is expanded, and is compli- 
cated by the projection into it of four folds. 

Another tooth, represented in Fig. 7, Plate II, likewise labeled "Alkali 



222 

Flat," has the appearance in condition of i)reservation, color, and wear, as if 
it might have pertained to the same individual as the former specimen. If 
so, it is related to it apparent!}' as the last premolar to the first molar. The 
antero-posterior diameter of the crown is nearly 16 lines; the transverse 
diameter is 19 lines. The basal ridge and inner lobes are as in the former 
tooth. Traces at the bottom of the oblique valley appear to indicate a dispo- 
sition to the formation of two folds like those existing in the same position in 
the larger tooth. 

It is not unlikely that this second molar tooth may be a true molar of the 
preceding species. 

The crown of a lower molar tooth, represented in Figs. 24, 25, Plate VII, 
from Bridge Creek, is supposed to belong to R. imcificus. It measures 20 
lines fore and aft, and 1 inch transversely, at base. 

HADROHYUS. 

Hadrohyus supremus. 

Among the Condon collection of Oregon fossils there are several, apparently 
of a large pachyderm, differing from those previously indicated, and likewise 
different in character from such as have been heretofore described. 

Fig. 26, Plate XVII, represents a fragment of a tooth which I have sup- 
posed to be a last upper premolar. The crown of the tooth would appear in 
its entire condition to have nearly the form and construction of the corre- 
sponding tooth of the Oreodonts, but differs especially in the proportionately 
less degree of development of the inner lobe and the greater degree of pro- 
duction of the inner basal ridge. The remains of the inner lobe have the 
appearance of being composed of a nearly connate pair, which no doubt 
would be found better developed and more distinct in the succeeding teeth. 
In the specimen the inner lobe appears notched, and the dentine is exposed 
on the outer lobe and the anterior division of the inner lobe. 

The transverse diameter of the specimen is 1^ inches. The tooth is 
labeled "Alkali Flats," and may be regarded as representing the animal to 
which the above name is given. 

Another specimen pertaining to an animal as large as that to which the 
tooth just described belonged, and perhaps actually belonging to the same, 
consists of a brain-cast, or rather the cast of the interior of a cranium. The 
cast has nearly the size and shape of the brain of a horse. The cerebral 



223 

hemispheres arc nearly as much convohitcd as in the latter, and measure 
about Ah inches in length and breadth. 

A third specimen, which may likewise be suspected as belonging to Had- 
rohyus, is a large atlas, which measures 5 inches in width between the outer 
acute borders of the articular cups for the occipital condyles, and about 4i 
inches from the neural tubercle to the hypapophysis. The vertebra differs in 
several important points from the atlas of the rhinoceros, horse, ox, &c., but 
the want of the requisite means of comparison prevents me from determin- 
ing its nearer relationship. 

AN UNDETERMINED CARNIVORE. 

A supposed carnivorous animal of large size is indicated l)y the portion of 
a large canine tooth, represented in Fig. 26, Plate VII. The specimen per- 
tains to the Condon collection of Oregon fossils. 

CHELONIA. 

TestudinidiB. 

STYLEMYS. 

The extinct genus of turtles above named, and originally described from 
remains found in the Miocene Tertiary formation of the Mauvaises Terres of 
White River, Dakota, was most nearly related with the existing land-tortoises. 
The shell is of the simplest form, and is about as prominent as in the less 
vaulted forms of the living species of Testudo, or the more vaulted ones of 
the terrapenes. The proportions nearly accord with those of our southern 
gopher, but the carapace is more uniformly convex. 

The carapace is most prominent just back of the middle, and is abruptly 
rounded posteriorly as usual in the tortoises. The margin is entire, feebly 
emarginate in front, somewhat expanded and everted over the axillary spaces, 
and in a less degree everted over the inguinal spaces. 

The plastron holds the ordinary proportions to the carapace as in Testudo 
and Emys. It is for the most part flat, and only moderately turned up in 
front. The extremities are nearly equal and rounded. The anterior is 
slightly narrowed ; the posterior is moderately notched. 

The number, shape, and relations of the bones of the shell are nearly the 
same as in Testudo and Emys. The number of the vertebral plates is ten, 
occasionally eleven, from subdivision of the usual eighth plate. 



224 

The ninth plate appears like a correspoiuling pair of costal plates connate 
in the median line. The tenth plate is lozenge-shaped, and occupies a 
similar shaped interval of the ninth vex'tebral and the pygal plates. 

The eight pairs of costal plates in their alternate narrowing and widening 
toward the extremities resemble those of the living tortoises, though the 
variation is not so great as usual in these. 

The interior of the vertebral plates of Styleuiys exhibits a deep, narrow, 
keel-like ridge, as represented in Fig. 6, Plate III, and Fig. 9, Plate XIX, in- 
tended for union with the neural arches of the vertebrae. A similar con- 
dition exists in the Gallipagos and other living tortoises. 

The costal capituli, as seen in Fig. 6, Plate III, and Fig. 9, Plate XIX, 
are feebly developed as in most species of Testudo, but are not reduced to 
the rudimental condition observed in our gopher. 

The first pair are as well developed as usual. The sixth and seventh pairs 
unite with processes of the corresponding vertebral plates. The eighth and 
ninth pairs, better developed than those in advance, unite in the root of the 
process of the eighth costal plate for the attachment of the pelvis. 

The scutes of both the carapace and plastron of Stylemys correspond with 
those of Testudo. The pygal scute is single as in all living tortoises, except 
Manouria. The pectoral scutes are very narrow, as usual in Testudo. 

The thickness and strength of the shell of Stylemys is greater than ordi- 
narily in the latter, liut proportionately not more so than in several living 
species. 

The bones of the limbs, so far as we are acquainted with them, approach 
in character those of the tortoises. The concavity above the articular surface 
of the distal extremity of the humerus, but especially of the femur, is deeper 
than in the living forms. 

The remains of Stylemys are apparently referable to three species, all 
geographically and perhaps geologically separated. 

Stylemys nebrascensis. 

The remains of this species form one of the most abundant fossils of the 
Miocene Tertiary deposit of the Mauvaises Terres of White River, Dakota. 
A multitude of specimens of nearly entire shells have been collected by all 
explorers of the locality in which they are found. Tliey present a great 



variety of age, size, aiid coiulilioii ol' prcsicrvalion. Many exhihil in tlicii- 
clistortioii evidences of considerable pressure, while others are so well pre- 
served as to appear entirely iitibroken. Their varied conditions, added to 
slight anatomical variation, led me at first to attribute them to five different 
species, which I now view as one. 

Mature speciinims are comparatively rare, at least in an entire condition 
One, broken into two pieces, is represented in Plate XXIII of "The Ancient. 
Fauna of Nebraska."' A second, more complete, was obtained by Professor 
Hayden for the Academy of Natural Sciences of Philadelphia. 

Very few other bones of Stylemys nebrascensis, other than those of the 
shell, have come under my notice. Among hundreds of shells and fragments 
of others, I never met with any portions of the skull or jaws. 

Fig. 10, Plate XIX, represents a fragment of tlic scapula with part of its 
precoraco'id. It agrees with the corresponding portion of the Ijone in Testudo. 

Fig. 7, of the same plate, represents the distal extremity of a humerus of 
a youtig individual. The hollow above the articular surface is rather deeper 
than in Testudo. 

Stylemys niobrarensis. 

Numerous fragments of shells and a few portions of other bones of a 
second species -of Stylemys were discovered by Professor Hayden in the 
Pliocene sands of the Niobrara River in the year 1857. • All the anatomical 
characters of the specimens indicate the same genus as the former, but 
several of them point to a different species. It was about the same size as 
the S. nebrascensis. 

Fig. 4, Plate III, represents the anterior portion of a plastron of the 
natural size, and therefore supposed to have belonged to a young animal. The 
episternals are more prouiinent forward than in S. nebrascensis, and they are 
deeply excavated beneath the broad scute-covered margin, which is not the 
case in the species just named. 

Fig. 5 represents the last vertebral and the pygal plates ol" . an 
older animal. It shows that the investing scute is single, as in Testudo. The 
lower margin of the pygal bone is slightly but decidedly everted, which is 
not the case in S. nebrascensis. 

Fig. 6 represents an inner view of a portion of a carapace one-halt the 
natural size. It belonged to a mature animal, aiul is the most (Complete por- 
20 a 



226 

tion of the shell of the species whicli has been submitted to me. It com- 
prises the vertebral plates from the sixth to the ninth inclusive, and portions 
of the corresponding costal plates on each side. The narrow character of the 
costal capitida is observable in the sixth and seventh pairs ; and the two suc- 
ceeding pairs are observable as they spring from the strong process for the 
attachment of the pelvis. 

Fig. 8, Plate XIX, represents the distal extremity of a right humerus, and 
Fig. 6 the same part of a left femur, both half the natural size. The femur 
would appear to have belonged to a larger animal than the humerus. The 
concavity above the articular surface is much deeper tlian in other known 
turtles. The l)readth of the femur, at the condyloid eminences, is 32 lines ; 
that of the humerus, in a corresponding position, has been nearly the same. 

Stylemys oeegonensis. 

An isolated vetebral plate, in the Condon collection of Oregon fossils, is 
supposed to indicate a third species of Stylemys. The specimen was found 
on Crooked River, and is represented, one-half the natural size, in Fig. 10, 
Plate XV. It exhibits a transverse groove defining two vertebral scute areas, 
and on the interior a narrow crest for union with the corresponding neural 
arch. The plate appears to be the third of the series, and is tliicker in pro- 
portion with its length and breadth than would appear to be the case in the 
preceding species of Stylemys. The specimen is 2 inches wide, IJ inches 
long, and 7 lines thick. 



DESCRIPTIONS OF REMAINS OF VERTEBRATA FROM TERTIARY 
FORMATIONS OF DIFFERENT STATES AND TERRITORIES 
WEST OF THE MISSISSIPPI RIVER. 



The fossil remains described in the succeeding pages consist mainl\' of 
isolated specimens obtained from Tertiary formations in various parts of the 
country west of the Mississippi River. They are nearly all remains of mam- 
mals. Included in the series there are descriptions of a few other Tertiary 
mammalian fossils, from the country east pf the Mississippi, described on 
account of their relation with the former, and for the most part for the first 
time. 

MAMMALIA. 

Order Carnivora. 
FELIS. 

FeLIS AUC4USTUS. 

Several teeth in fragments of jaws, and portions of other teeth, indicate a 
sjjecies of tiger apparently diiferent from any previously described. The 
specimens were discovered by Professor Hayden, during Warren's expedition 
of 1857, on the Loup Fork of the Niobrara Eiver, iSTebraska. They belong 
to the Pliocene Tertiary formation, and were found in association with remains 
of Mastodon mirificus, Merychyus elegans, Frocamelus occidcHtalis, &^'c. 

The most characteristic of the specimens, represented in Fig. 19, Plate VII, 
is an upper sectorial molar contained in a small jaw-fragment. The tooth is 
about the size of that of the Bengal tiger, and is therefore too large to have 
belonged either to the panther or the jaguar. It is as much too small to 
have belonged to the extinct American lion, or Felis atrox, as its l)Veadth is 
but little greater than the sectorial molar contained in tlie lower jaw from 
which the latter was described. The form of the tooth is the same as in the 
American panther and Bengal tiger. The breadth of the crown is slightly 
less, and its thickness proportionately greater than in the corresponding teeth 
of a skull of the latter with which the fossil was compared. 



228 



If the upper sectorial molar of Fells atrox had the same proportionate size 
to the lower one as in the Bengal tiger and other feline animals, it measured 
nearly an inch and three-fourths in breadth. That of the Loup Fork fossil 
is a little over an inch and a quarter in breadth. From the difference iu size 
thus indicated between the sectorial molar of the Loup Fork fossil and that of 
the previously described largest American cats, recent and extinct, we -may 
fairly regard the specimen as characteristic of another species, for which the 
'name heading this chapter has been proposed. 

Comparative measurements of the upper sectorial molar are as follows — 
those from Fells atrox being estimated, and that from the jaguar being taken 
from Plate XIV of De Biainville's Osteographie: 



Upper sectorial molar. 


F. concolor. 


F. onfa. 


F. augustus. 


F. tigiis. 


F. atrox. 


Breadth of crown 

Tliif'lcnp.ss in front 


Lilies. 
11 
5J 


Lines. 
12 


Lines. 

15J 

8 


Lines. 

16 


Lines. 
20 
10 







Another Specimen, represented in Fig. 18, Plate VII, consisting of a frag- 
ment of a premaxillary retaining the second incisor, the first alveolus, and part 
of the last one, agrees in size and other characters with the corresponding 
part in the Bengal tiger. 

The remaining specimens are fragments of an upper last premolar and of a 
canine from the same individual. 

A specimen, represented in Fig. 24, Plate XX, found by Professor Hayden 
on the Niobrara River, but not in proximity with the preceding, consists of 
the distal extremity of a humerus, probably of the same animal. It has 
about the same size, proportions, and form as in the corresponding part of 
the arm-bone of the Bengal tiger. Its diameter at the supracondyles is 3| 
inches ; the breadth of the articular surface in front is 2| inches. The hole 
for the brachial blood-vessels and accompanying nerve is quite evident, though 
the bony bridge defining it is broken. 

Felis imperialis. 

Among a collection of fossils belonging to the cabinet of Wabash College, 
Crawfordsville, Indiana, purchased from Dr. Lorenzo Y. Yates, of Centreville, 
Alameda County, California, there are several which were kindly loaned to 



229 



mc for investigation. The specimens consist of jaw-fragments of a large 
wolf and tiger. 

Professor E. O. Hovey writes me that they are part of a collection of fossil- 
bones which were obtained from a wash in the side of a hill about twenty- 
five miles inland from San Leandro, California. 

The fossils are not petrified, and indeed have undergone almost no altera- 
tion, and are probably quaternary. 

The fossil pertaining to a tiger consists of an upper-jaw fragment, repre- 
sented in Fig. 3, Plate XXXI, one half size. It contains the second pre- 
molar, and retains the alveolus of the one in advance and that of the canine. 

The specimen indicates a species as large as the largest living Bengal tiger, 
and, indeed, is slightly larger than the corresponding part of the largest spec- 
imen of a skull among many in the Academy Museum of Philadelphia. 

The proportions of the specimen indicate a larger animal than the extinct 
Fells augustus^ as represented by the fossil-fragments from the Niobrara 
River of Nebraska. They also indicate an animal as much smaller than the 
extinct F atrox, as represented by the ramus of a lower jarw found in associ- 
ation with remains of the Mastodon americnnus and Megalonyx Jeffersoni, 
near Natchez, Mississippi, as the Bengal tiger is compared with the latter. 

Taking into consideration the extent of variation in size of the same 
species, there can be no question that the California fossil might pertain to 
either the Felis augustns or the jP. atrox. Its associations might aid in the 
determination whether it was either of these, or whether it is distinct. If 
found in association with remains of Alastodon americanus, it might reason- 
ably be supposed to pertain to a smaller individual of Felis alrox ; if with 
any of the peculiar species of the Niobrara fauna, it might be supposed to be 
a larger individual of F. augustus. 

Comparative measuremeuts of the fossil with the corresponding portion of 
the skull of a large Bengal tiger from Hindostan are as follows : 





Fossil. 


Bengal 
tiger. 


Space occupied by the upper premolars and canine 


Lines. 
34.0 
21.8 
1-J. 2 
14.0 


Lines. 
33. .5 


From back of lust premolar to canine alveolus 


19.0 


Antero-posterior diameter of second premolar 


12.0 


Diameter of canine alveolus . . . . '. 


13.5 


• 





230 



CANIS. 

Can IS INDIANENSIS. 

The fossil specimen pertaining to a wolf consists of the right ramus of a 
lower jaw, represented in Fig. 2, Plate XXXI. The specimen indicates an 
animal larger than any individuals of tiie recent wolves of North America 
and Europe, as represented by skulls I have had the opportunity of examin- 
ing in our Museum of the Academy. It, however, indicates a less robust 
animal than that formerly described by me under the name of Canis primcevus, 
and subsequently as C. indianensis, from an ujjper-jaw fragment, found in 
association with reiliains of Megalonyx, &c., on the banks of the Ohio River, 
Indiana. 

The specimen likewise indicates a less robust species than the C Haydeni, 
of the Pliocene formation of the Niobrara River, but a larger one than C. 
scevus, of the same formation. 

I am disposed to view the specimen as pertaining to the C indianensis, 
and perhaps it was not different from the existing C. occidentalis. 

Measurements of the fossil, in comjiarison with those of the skull of a large 
wolf from the Columbia River, Oregon, and of another from Germany, are as 
follows : 



Fossil 
jaw. 



Oregon 
wolf. 



European 
wolf. 



Length of jaw from condyle to fore part of canine 

Beptli of jawat condyle 

Depth of jaw at corouoid process 

Depth of jaw at sectorial molar 

Depth of jaw at second i^remolar 

Length of molar series with caniue . . „ 

Length of molar series 

Anteroposterior diameter sectorial molar 

Anteroposterior diameter caniue 



Lines. 
96.0 
21.2- 
40.0 
18.0 
16. G 
66.»0 
54.0 
16.4 
8.4 



Lines. 

90.0 
20.5 
36.4 
17.0 
14.0 
61. 
50.0 
14.6 
6.8 



Lilies. 

86.0 
20.5 
37. 5 
15.0 
12.5 
55.4 
45.0 
14.3 
6.2 



LUTRA ? 

A specimen of a tibia, submitted to my inspection l)y the Smithsonian 
Institution, is represented in Fig. 4, Plate XXXI. It was presented by 
Clarence King, and was obtained by him on Sinker Creek, Idaho, in associ- 
ation with remains of Equus excehus and Mastodon mirificus. 



231 

The tibia pertains to a carnivore, and resembles Ihat of an otter more than 
that of any other animal witii which I have an opportunity of comparing it. 
Its differences, excepting size, are trifling. The tubercle for insertion of the 
quadriceps extensor is less prominent, so as to give the head of the bone pro- 
portionately less thickness in relation with its breadth. The ridge for the 
•attachment of the interosseous membrane at the lower part of the bone is 
more prominent and sharper. The distal end in front just above the- articu- 
lation is flatter, and the groove for the flexor tendons behind is deeper. 

Liues. 

Length of the bone internally 50 

Width of the head 1.5 

Thickness at the inner condyle lOA 

Width of the distal end between the most prominent points , 11 

Thickness at the inner malleole 8 

Order Proboscidea. 
MASTODON. 

Mastodon obscurus. 

Besides the well-known American mastodon, M. americaniis, of the post- 
Tertiary period, there appear to have been at least three others which in- 
habited this continent. Characteristic remains of a species, to which the 
name of M. mirijicvfi was given, were discovered by Professor Hayden, in 
association with an abundance of remains of many other extinct animals in 
the Pliocene formation of the Lonp Fork of Platte River, Nebraska. Re- 
mains also, apparently of the same species as the South American M. andium, 
have been foOnd in Central America. For an account of the remains of the 
two species last named, the reader is referred to the "Extinct Mammalian 
Fauna of Dakota and Nebraska." 

In the Mnseum of the Academy of Natural Sciences of Philadelphia, 
there is a cast in plaster of a mastodon tooth, the original of which is nsputed 
to have been found in the Miocene formation of Maryland. The original 
specimen having been lost, the cast is represented in Fig. 13, Plate XXVII. 
of t-he work just named. This, together with the fragment of a similar 
tooth, represented in Fig. 1 6, of the same plate, has been taken in evidence 
of the existence of a fourth species, to which the name of M. ohsatrus has 
been given. 

Dr. Lorenzo G. Yates, of Centreville, Alameda County, California, has 
communicated to the writer a list of localities in which he has discovered re- 



232 ■ . 

iiiaiufi of mastodons in that Stale. Specimens collected by him were sent to 
Professor C U. Shrpurd, of Ainlierst, Massachusetts, who has submitted 
them to the examination of the author. 

One of the specimens, a last inferior molar tooth, represented in Figs. 1, 2, 
Plate XXI, was found together with the mutilated lower jaw and upper molars, 
at Oak Springs, in Contra Costa County. The remains were obtained from 
the rock at the' base of one of the rounded hills, of Tertiary age, mentioned 
in Professor Whitney's Geological Survey of California, p. 32, stretching 
along near the edge of the San Joaquin plain. According to Mr. William M. 
Gabb, the formation belongs to the PHocene Tertiary period. 

A small photograph, sent to me by Dr. Yates, exhibits the lower jaw with- 
out the ascending portions- behind, and with straight tusks projecting with an 
upwar-d direction. The tusks appear to be as long as the jaw was in its com- 
plete condition. 

The molar tootli has the same general form and constitution as the corre- 
sponding one of the American mastodon, but is smaller than is usual in this 
species. It resembles the plaster-cast above mentioned sufficiently to render 
it pi'obable that it belonged to the same animal. 

The crown of the tooth is composed of four transverse pyramidal ridges, 
each consisting of a pair of lobes, and conjoined in a common, broad, low 
base, without a conspicuous offset- or heel. As in the cast of the Maryland 
tooth, the inner lol^es are more mammillary or less angular than in M. ameri- 
canus. In this respect they approach the condition, even more marked, how- 
ever, in the M. angustidens of Eui'ope, and they are well separated to their 
base as in M. americamis. The outer lobes of the crown have the same form 
as in the latter, but are provided with distinct offsets projecting from their 
inner part fore and aft. The contiguous- offsets come into contact, and thus 
obstruct the transverse valleys of the crown. This arrangement accords 
with that of the cast of the Maryland tootli. In M. ^wmcrtwws similar offsets 
from the outer lobes are usually but feebly developed, and scarcely obstruct 
the bottoms of the ti^ansverse valleys. 

The enamel worn from the summits of the anterior of the inner lobes 
leaves a transverse ellipsoidal cup of exposed dentine, as usual in the same 
position in the American mastodon. A greater degree of wearing on the 
corresponding outer lobes has produced quadrilobate excavations of dentine, 
in which the specimen agrees with the plaster-cast. In the same stage of 
wear in M. ainericaniis, the excavations have a more lozenge-like outline. 



233 



Tlic anterior three divisions of tlie crown arc nearly alike in size and con- 
struction. The fourth division is less well developed, and consists of a pair 
of conical lobes, but the inner is much smaller than the other, and is connate,, 
with a supplemental lube in advance. Back of these there is a small conical 
tubercle, corresponding with the heel or rudimental fifth division of the crown 
in M. americanus. 

In the plaster-cast of the Maryland tooth, the fourth division of the crown 
consists of a pair of nearly equal conical lobes, embracing a smaller pair 
at their fore part. Behind these there is a pair of conical tubercles corre- 
^nding \yith the single one in the California tooth. The ditlerences indi- 
cated between the posterior extremity of the crown of the latter and the 
cast of the Maryland tooth are not greater than those observed between the 
same teeth of diflferent individuals of M. americanus, and are therefore unim- 
portant as distinctive characters. 

Well-developed elements of a basal ridge, in the California tooth, occupy 
the outer fore part of the crown and the intervals of the outer lobes. Between 
the posterior three divisions of the crown they are better marked than in the 
cast of the Maryland tooth, or even than is usually the condition in the 
American mastodon. The ridge is also distinctly produced around the outer 
part of the third and fourth external lobes and the back of the crown, which 
is not the case in the cast, nor usually in M. americanus. 

The jaw-fragment containing the tooth is too much mutilated to ascertain 
anything of importance in regard to it, other than that it measured about 6.^ 
inches in depth at the fore part. 

. Comparative measurements of the California tooth, the cast of the Mary- 
land tooth, and two teeth of M. americanus are as follows : 





California. 


MaryhuKl. 


M. americauns. 




Female. 


Male." 


Fore and aft diameter of crowu 

Breadth at anterior tliree ridges 

Breadth at fourth ridge 

Height of third inner lobe, unworn 


Lines. 
75 
33 
25 
25 
10 
■ 24 


Lines. 
75 
33 
28 
26 
20 
22 


LAncs. 
75 
38-42 
33 
28 
20 
22 


Lines. 

90 

41-45 

39 

34 


Height of fourth inner lobe 


30 


Height of fourth outer lobe 


30 







' The 8i>ecimeu of the tooth of a male has iive transverse divisions to the crown in addition to a small 



heel. 



30 G 



. 234 

The second specimen received from Professor Sliepard consists of the 
fragment of a tusk, from Dry Creek, Stanislaus County, California. It was 
discovered by Dr. Yates imbedded in the bluff of a hill, about ten feet above 
the bed of the creek. The hill, upward of a hundred feet in height, is one 
of those mentioned in Professor Whitney's Geological Sux-vey as being 
scattered over the San Joaquin plain, at the base of the foot-hills of the 
Sierra Nevada. 

The specimen is represented in Figs. 3, 4, Plate XXI, and is remarkable 
from its exhibiting characters which indicate the species to have been nearly 
related with the Mastodon augustidens of Europe. The molar tooth frdit 
Contra Costa County, likewise presents a form which approximates it to the 
same animal, so that it is probable both specimens may belong to the same 
species. 

The fragment is six inches long, sliglitly curved in two directions, and in 
transverse section (Fig. 3) is ovate, with the anterior pole acute. The pulp- 
cavity, opening half the diameter of the tusk at its larger broken end, extends 
half the length of the specimen. On one side of the tusk, as in Mastodon 
augustidens, there is a broad layer of enamel, which extends from the acute 
border two-thirds the width of the specimen. The enamel is somewhat 
rugose, and is two-thirds of a line thick. In one position, near the smaller end 
of tlie fragment, it has been worn through irregularly for the extent of about 1 J 
inches. The convex or thicker border of the tusk has also been worn off to 
an extent of two-fifths of the surface. The broken ends of the fragment exjiibit 
the usual decussating lines of structure of the dentine so characteristic of 
the ivory of the great proboscidians. 

The entire length of the tusk appears to have approximated two feet. The 
other dimensions are as follows : 

Linos. 

Long diameter of the larger extremity 28 

Short diaTueter of the larger extremity 19 

Long diameter of the .smaller extremity 22 

Short diameter of the smaller extremity IG 

Breadth of enamel layer at larger extremity 22 

Breadth of enamel layer at smaller extremity 19 

In the form of the tusk and the possession of an enamel band it resembles 
the same organ in the Mastodon augustidens. The specimen when first de- 
scribed was viewed as probably representing a species distinct from that to 
which the Contra Costa specimens pertained, and was therefore referred to an 



235 

animal with the name of Mastodon Shcjmrdi, in honor ot" Professor C. U. 
Siicpard. 

Since writing the above, I have received another specimen from Professor 
Shepard, consisting of a last inferior molar tooth, obtained hy Dr. Yates in 
Contra Costa County, California. It is almost identical in form and size with 
the one previously described from the same locality, but appears to have l)e- 
longed to an older individual, as indicated by the more worn condition. 

From the Smithsonian Institution I have recently I'eceived for examination 
some remains of a mastodon and an elephant, which were found near Santa 
Fe, New Mexico, and were presented to the institution by the Hon. W. F. 
M. Arny. The mastodon remains consist of three fragments of a lower jaw, 
a vertebral body, and a rib-fragment. They are white, and from adherent jior- 
tions of matrix appear to have been imbedded in an indurated clay. The 
cancellated structure of the bones is filled with the same matter together 
with crystalline calcite. 

The lower-jaw fragments appear all to have pertained to the same specimen. 
One of them, repi'esented in Fig. 1, Plate XXII, consists of a portion of the 
right ramus containing the last molar tooth nearly of the size of the corre- 
sponding part in the American mastodon. The molar tooth, represented in 
Fig. 4 of the same plate, has lost the portion back of the third ridge of the 
crown. The portion preserved sufficiently resembles in its construction the 
corresponding portion of the California tooth above described to behmg to 
the same species, which I suspect actually to he the case. It also resembles 
more nearly the corresponding portion of the same tooth of M. augustidens 
of Europe than it does that of the M. americanus. 

The other jaw-fragments, represented in Figs. 2, 3, form together the 
anterior, extremity of an enormously prolonged symphysis, like that of J/. 
augvstidens. The specimen is rather more than a foot in length, and contains 
jiortions of tusks extending through the pieces and broken ofl" on a level with 
the extremities of the .symphysis. This has been somewhat crushed laterally, 
so as to disarrange the proper relative position of the two tusks. It is ot 
nearly uniform width, but widens at the posterior extremity. Below, it is 
slightly convex or nearly straight longitudinally, and is depressed along the 
median line. The sides are convex, and extend upward in ridges which form 
the boundaries of a deep groove at the upper part of the symphysis. The 
groove is narrower behind, and becomes shallow in front. The tusks are 



23() 

slightly compressed cylindrical, and curved in their course. They are oval in 
transverse section, with the long diameter directed from within upward and 
outward. They are unprovided with enamel, and at the broken ends exhibit 
the decussating curved lines of structure of the ivory enveloped in a thick 
layer of dense cementum. At the posterior extremity the broken ends ex- 
hibit the pulp-cavity occupied with matrix and surrounded with a margin of 
about a line in thickness, so that the symphysis is broken off near the bottom 
of the incisive alveoli. 

Frooi the thinning of the anterior alveolar borders of the symphysis it 
would appear as if the latter was nearly complete, so that if we Siippose the 
lower tusks projected about 6 inches from the jaw, it would give them an 
entire length of about 20 inches. 

The breadth of the fore part of the symphysis, in its complete condition, 
is rather more than 5 inches. At the back part, corresponding with ttie posi- 
tion of the bottom of the incisive alveoli, it has been about an inch wider. 

The long diameter of the tusks, at their anterior broken ends, is about 20 
lines; the short diameter 17 lines. These diameters are nearly uniform 
throughout as existing in the specimen. 

The fore and aft diameter of the last molar tooth, when complete, is esti- 
mated to have been full (ij inches. The width of the crown at the base of 
the second and third ridges is 35 lines. The measurements indicate the pro- 
portioBS of the tooth to be slightly greater than in the corresponding Califor- 
nia tooth or the cast of the Maryland toyth. 

The depth of the lower jaw below the second ridge of the last molar is 6^ 
inches ; and the thickness is 5 inches. 

I think it probable, without being positive in the matter, that the Masto- 
don remains above described, which have been referred to species under the 
names of Mastodon ob.scurus and M. Shepardi, including those from New Mex- 
ico, belong to one and the same species. This, from the form of the molar 
teeth, the constitution of the upper tusks, and the prolonged symphysis of 
the lower jaw, was clearly a near relation of the Mastodon augustidens of 
Europe. 

In a note, on page 74, of volume II, of the Palaeontological Memoirs of the 
late Dr. Falconer, it is stated that at Genoa he had seen a cast of a lower jaw 
of a mastod'on from Mexico, with an enormous iec abruptly deflected down- 
ward, and containing one very large incisor. The beak is much thicker than in 



237 

M. augusUdens and larger than in M. loitgirostris. • ".The outline of the jaw re- 
sembles very uuich the figiira in D'Orliigny's voyage, descriljed by Laurillard 
as M. andium. The Genoese paleontologists had named it lihynchotherium, 
from the enormous development of the beak, approaching Dinotherium.'' 

Perhaps this Mexican specimen of a lower jaw may pertain to the same 
species as the specimens above described, though tlie beak of the New Mex- 
ican specimen is unlike that of the figure above alluded to in tiie work of 
D'Orbigny. 

The vertebral body and rib-fragment accompanying the jaw-fragments from 
New Mexico present nothing remarkable. The former is of a lumbar verte- 
bra, and would indicate an animal about as large as the living Asiatic elephant. 
Its length is 34 lines; its breadth is about-5 inches at the posterior border; 
and its height is 3^ inches. 

Mastodon mirificus. 

Some small fragments of jaws and teeth, apparently referable to this species, 
in the museum of the Smithsonian Institution, were obtained by Mr. Clarence. 
King, from Sinker Creek, Idaho. 

Mastodon amkricanus. 

Among a collection of remains of the American mastodon, from Benton 
County, Missouri, deposited in the museum of the Academy of Natural Sciences 
of Philadelphia by the American Philosophical Society, there is a singular' 
tooth, which I suppose to be of abnormal character and to pertain to the 
Mastodon americanus. The specimen is in the same state of preservation as 
the associated remains, and is repre.sented in Figs. 5 and 6, Plate XXII. It 
consists of the complete crown of a molar tooth without the fangs. Its shape 
is so peculiar that I can form no clear idea as to the relative position it occu- 
pied in the jaws, or as to its homologous character in comparison with normal 
teeth. 

The crown in transverse outline is irregularly oblong oval, more bulging 
on one side than the other, and somewhat prolonged at the extremities. From 
a thick expanded base there project four conical lobes, of which the interme- 
diate two are nearly equal and nearly twice the size of the others, also nearly 
equal in size. The basal ridge on the more prominent side of the crown is 
mammillated, and twice the depth that it is upon the other side, in which 
l)Osition it is comparatively smooth. 



238 

The long diameter of the crown is 55 lines ; the short diameter, 29 lines. 

A small collection of fossil teeth, from near Pittstown, on the Susquehanna 
River, in Luzerne County, Pennsylvania, now jjreservecl in the Museum of the 
Academy of Natural Sciences, is of interest on account of the association. 
The specimens consist of two molai's of Equus major^ hereafter described, a 
molar of Bison kU/frons,.£dso to be described, and three first premolars, ap- 
parently from as many different individuals of Mastodon americaiius. Of these 
one is represented, of the natural size, in Fig. 9, Plate XXVIII. 

ELEPHAS. 
Elephas americanus. 

In the preceding account of the remains of mastodon from near Santa 
Fe, New Mexico, those of an elephant are referred to which were found 
in association with them. There is but one specimen, consisting of the back 
part of a molar tooth, apparently the last upper one. It is composed of eight 
unworn lobes, decreasing successively in length. They present the ordinary 
thin, elongated, palmate appearance, with the digitate extremities curving for- 
ward and ending in manimillary points. The eight plates occupy a space 
of 4| inches. The second of 'the .plates is 3f inches broad near the middle,- 
and when entire was upward of 7 inches in length. 

The specimen is insufficient to determine whether it pertained to a species 
different from the ordinary Eleplias amei-icanus, and it presents nothing pecu- 
liar. The thickness of the lobes, or double plates, indicates the coarse-plated 
variety of teetli of the American elephant, named by Dr. Falconer Elephas 
columhi. 

Since the above was written I have received; from the Smithsonian Insti- 
tution, for examination some remains of an elephant from Chihuahua. Pro- 
fessor Baird rej)orts that the remains came from an ancient lagoon-bed at 
Potos Spring, seventy-five miles south of El Paso, Texas, and were presented 
to the institution by General Carleton, United States Army. 

The specimens consist of fragments of molar teeth with adherent gravel, 
and with the exterior cementum much worn away by water action. Tliey 
indicate the coarse-plated variety of teeth of the American elephant. One 
of the better preserved specimens consists of the fore part of a last lower 
molar about one-third worn down. It comprises about eight lobes, or double 
plates, included in a space of 5| inches. The width of the sixth lobe is 3*f 



239 

inches. The first lobe is nearly obliterated, and its back plate conjoins tlie 
contiguous one of the second lobe. 

Another specimen consists of the ])ack part of a molar with six lobes, 
occupying a space of nearly 4^ inches. The lobes exhibit the same narrow, 
elongated, palniated form, with curved digitate extremities, as in the molar 
fragment from New Mexico. The first of the six lol)es is worn off at the 
summits of the digitate ends. The others are unworn, and the second plate 
is 3| inches wide near its middle. 

MEGACEROPS. 

Megaceeops coloradensis. ■ 

An imperfectly known extinct animal, which was supposed to be related 
with the great ruminant, the Sivatherium of the Tertiary formation of the 
Sewalik Hills of India, is indicated by a singular looking fossil discovered in 
Colorado. The specimen belonged to Dr. Gehrung, of Colorado City, by 
whom it was presented to Professor Hayden. It is represented one-half the 
natural size in Figs. 2, 3, Plate I, and Fig. 2, Plate II, and was originally 
described in the Proceedings of the Academy of Natural Sciences of Phila- 
delphia for January, 1870, under the name heading this article. 

The fossil is singularly puzzling in its character, and possesses so little in 
common with the homologous portion in ordinary animals that its relation- 
ship would have remained unknown, or entirely conjectural, had we not been 
previously acquainted with the Sivatherium. The specimen appears to cor- 
respond with that portion of the face of the latter which comprises the upper 
part of the nose, together with the forehead and the anterior horn-cores. As 
is described to be the condition in the corresponding portion of the skull of 
Sivatherium, all the bones entering into the constitution of the fossil are 
completely co-ossified, so as to leave no traces of the original course of the 
sutures. The nasal and contiguous bones arc of great thickness, and as solid 
as those generally in the living Sirenians. 

The horn-cores of the Colorado fossil resemble the anterior ones of Siva- 
therium both in form and relative position. They are large, dense, conical 
knobs, somewhat trilateral, and with a rounded, dome-like smnmit, which is 
more porous on the surface than any other part of the fossil. They are 
nearly straight, and divergent from each other, and their summits project 
more over their base externally than in Sivatheriinn. 



240 

The space between the horn-cores extending across the forehead forms a 
deep concavity divergent outwardly. The surface of the forehead from the 
broken border of the specimen behind to the end of tlie nasals forms a mod- 
erate uninterrupted convexity. In Sivatherium, the rhinoceros, and the tapir, 
the corresponding surface is interrupted by a concavity at the root of the nose. 

The face, as formed by the nasals and tlicir apparent conjunction with the • 
maxillaries in advance of the position of the horn-cores, is exceedingly short 
in comparison with the corresponding part in Sivatherium and the rliinoceros, 
and is more like that in the tapir. 

The nasals together form a strong, thick, tongue-like process, projecting 
free from their conjunction with the frontals in advance of the horn-cores. 
The overhanging process of the nose is proportionately wider, thicker, and 
longer than that of Sivatherium. Its upper surface is not vaulted as in the 
latter and the rhinoceros, but simply continues the convexity of the forehead. 
The lateral margins are sqmewhat expanded, (not sufficiently expressed in 
Fig. 2, Plate I,) and are thinner than elsewhere. Tlie end is thicker than at 
the sides, is more obtuse than in Sivatlierium or the tapir, and is roughened 
and porous, probably to have given firmer attachment to a proboscis. A 
notch occupies the extremity of the obliterated internasal suture. 

One of the most remarkable characters of the Colorado fossil is the great 
comparative extent of the lateral nasal notch. It not only exceeds that of 
Sivatherium, but also that of the rhinoceros and tapir. In the former its 
bottom is far in advance of the position of the lK)rn-cores, and in the rhi- 
noceros it holds nearly the same relative position. In the tapir the notch 
extends back over the position of the orbits. In the Colorado fossil it 
extends far back beneath the position of the horn-cores, wdiere the nasals 
apparently conjoin the maxillaries. The relative position of the orbits cannot 
be ascertained in our fossil, as all the contiguous parts are broken away. 
They appear as if they had been situated farther posteriorly in relation with 
the position of the horn-cores than in Sivatherium. The horn-cores, project- 
ing forward and outward, overhang a large recess, which would appear to 
have been just in advance of the orbit, and is situated externally above and 
behind the lateral nasal notch. 

The broad and stout projecting nasals were probably intended as a point 
of attachment for a movable snout or proboscis, intermediate in degree of 
development to that of the tapir and elephant or mastodon. The similar 



241 

constitution of the nose ot SivHtlieriiuu led ils (li.scoverei- and descriher, Dr. 
Falconer, to attribute a like prehensile organ to tiiat animal. The strength 
and co-ossitication of the nasals, together and with the frontals and niaxilla- 
ries, are also no doubt related with the unusual position of the horn-cores, just 
as a similar condition of things in the rhinoceros is related with the support 
of a Iiorn on the nose. 

^[(gacerops coloradcnsis is estimated to have approximated two-thirds the 
size ot the Sivatherium g'lganteum. 

Measurements from the fossil referred to Mpgacerops coloradenus are as 
follows : 

luches. Liues. 

Distauce from the summit ot oue horucore to tbe otlicr ' 10 

Length of curve between the same two poiuts I'j 10 

Length of Literal nasal notch from end of nasals 1 

Distauce from end of nasals to center of space between liorncores 

Breadth of nasals 2^ inches behind the end 4 o 

Thickness of nasals where co-ossifiod ... « 1 3 

Diameter of born-cores 2i inches from summit fore and aft 2 10 

Diameter of horn-cores 2^ inches from saiiuuit transversely 2 5 

Breadth of face below born-cores 8 8 

Breadth at bottom of lateral nasal notches 5 6 

Since writing the above, I have recalled to mind a specimen of a horn-core 
which was obtained by Dr. John Evans from the Mauvaises Terres of AVhite 
River, Dakota, and which is noticed in the account of Titanotherium, on page 
216 of the " Extinct Mammalian Fauna of Dakota and Neliraska," The ref- 
erence of the specimen to any particular animal was considered very uncer- 
tain, though it was suspected that it might pertain to Titanotherium. It is 
now represented in Fig. 3, Plate XXVIII, and is seen by comparison to bear 
a near resemblance to the horn-cores of Megacerops. It is rather larger and 
slightly more tapering and curved than in the latter. The specimen may, 
perhaps, belong to another species of Megacerops. 

Since the foregoing was written. Professors Marsh and Coi)c have repoiied 
the discovery of i-emains of several huge nuimmals in the Bridger Tertiary 
beds, which they have described under the names of Tinoceras, Dinoceras, 
Eobasileus and Loxolophodon. The ordinal relations of these is a matter of 
dispute, and it is a question especially whether they are proboscideans, or are 
representatives of a previously unknown order. One of their most remarkable 
pecuharities is the possession of several pairs of bony jirotuberances to the 
skull, which are viewed as horn-cores. 
31 G 



242 

In a recent paper cntilled '-00 the Gigantic Fossil Mammals of the Order 
Diiiocerata,'' by Professor Marsh, published in the American Journal of Sci- 
ence for February, 1873, there is a representation of an almost complete skull, 
described under the name of Dinoceras mirahilis. This skull, which appears 
to agree with the corresponding parts, including the teeth, described in the 
preceding pages under the name of Uintatherium rohustum^ is represented 
with three pairs of bony protuberances, or horn-cores. In comparing the 
Colorado fossil, it would appear that the lun-n-cores accord with the second 
pair of the Wyoming fossil, in which they are seen to spring from the upper 
part of the maxillaries, where these join the nasals. 

The resemblance between the si^ecimen belonging to Megacerops and the 
skull described by Professor Marsh renders it probable that the former 
belongs to the same order, instead of to the ruminants, as previously sup- 
posed. 

Order Solidungula. 

EQUUS. 

Equus occidentalis. 

I The remains of equine animals which of late years have been discovered 
both in North and South America indicate a number of species and genera 
really wonderful, when we take into consideration that neither continent pos- 
sesses a single living indigenous species. The reiliains from many parts of 
North America, mainly consisting of isolated molar teeth, which have come 
under my observation, exhibit so much difference in size and variation of the. 
enamel- folding, as displayed on the worn triturating surface, that in many 
cases I have fliiled to refer them to species with any degree of certainty. 

In the Proceedings of the Academy of Natural Sciences of Philadelphia 
for 18(J5, page 94, I have given a notice of two specimens of upper molars 
from California, submitted to my examination by Professor J. D. Whitney, 
which were referred to a species uith the name of Equus occidentalis. One 
of these specimens is represented in Fig. 2, Plate XXXIII, and was obtained 
from auriferous clay, at a depth of thirty feet from the surface, in Tuolumne 
County, Cahfornia. 

Subsequently, in the same Proceedings for 1868, page 26, and in the 
"Extinct Mammalian Fauna of Dakota," &c., I described a number of re- 
mains obtained by Professor Hayden on Pawnee Loup Fork of the Platte 



243 



River, and on the Niobrara River, Nebraska, which I referred to a species 
with the name of E. excehus. A characteristic specimen referred to the latter 
consists of a portion of the upper jaw containing the back four molars, repre- 
sented in Fig: 31, Plate XXI, of the work last named. The teeth in this 
specimen are so nearly identical in character with those from California, 
referred to E. occidentalism as may .be seen by comparing the figure with 
Figs. 1, 2, Plate XXXIII, of the present work, that there can be little doul)t 
of the two named species being the same. 

Since the original description of the two specimens referred to E. occiden- 
talism I have seen others of half a dozen ditferent individuals from California. 
All these present sufficient correspondence in peculiarity of character as to 
render them fairly representative of an extinct species, for which the name 
of E. occidentalis is appropriate. Fig. 1, Plate XXXIII, represents a series 
of the anterior four upper molars contained in a jaw-fragment. Tlie speci- 
men, together with another similar one fiom a second individual, and contain- 
ing all the molars except the last one, were obtained by Dr. George H. Horn 
from an asphaltum deposit near Buena Vista Lake, California, and presented 
to the Academy. Similar specimens have also been submitted to my exam- 
ination, obtained at the same locality by Professor Whitney. 

The upper molar teeth of E. occidentalis are about the size of those of the 
larger varieties of the domestic horse. From them they arc in general 
readily recognizable l)y the greater simplicity in the course of tlie enamel 
lines, as displayed on the worn triturating surface, and in the absence of the 
small enamel-fold, directed inwardly, at the bottom of the oblique valley 
between the inner principal folds of the crown, in wliich point these teeth 
accord w'ith those of the existing ass. 

The measurements of the specimens referred to E. occidentalis and repre- 
sented in the figures are as follows : 



Specimen of Fig. 1. 



Diameter of first molar . . 
Diameter of second molar 
Diameter of third molar . , 
Diameter of fourth molar. 



Autero- 
liosterior. 


Transverse. 


iiwes. 


Lines. 


18 


13 


14^ 


14J 


144 


14.i 


12i 


134 



244 

Speciincii ot Fig. "2, representing a second ur third molar : 

Lines. 

LcTigtb externally 127 

Autero-posterior diameter of triturating surface 15j 

Transverse diameter 13i 

A tooth in the collection of" the Smithsonian Institntion, apparently refer-- 
al)le to the same species, was discovered by Mr. Clarence King on Sinker 
Creek, Idaho. 

Equus major. 

Figs. 3 to 1 7, Plate XXXIII, represent specimens, from different localities 
of the United States, which are viewed as pertaining to an extinct horse, 
originally referred by the author to a species under the name of Equus com- 
plicatus, and which is suspected to be the same as that which was first desig- 
nated by Dr. Dekay under the name of Equus major. 

Figs. 3, 4, 7 to 10, 12, 13, represent specimens of teeth submitted to my 
examination by Messrs. D. C Elliot and George N. Lawrence, of New York. 
They were obtained from an asphaltum-deposit and from a stratum of clay 
beneath, in Hardin County, Texas, and were found in association with remains 
of mastodon and other extinct animals. 

Figs. 3, 4 represent a first upper molar of the right side. It differs in no 
important degree from the corresponding tooth of the domestic horse, l)ut is 
somewhat larger than usual, and is less simple in the course of the enamel 
lines on its triturating surface. 

Figs 5, 6 represent a similar tooth, from Illinois Bluffs, Missouri, six miles 
west of Saint Louis. According to the late Dr. B. F. Shumard, it was derived 
from the quaternary formation of Missouri. 

Figs. 7, 8 represent a last superior molar of the right side, accompanying 
the first molar, from Hardin County, Texas. It is remarkable for its great 
extent of curvature compared with the corresponding tooth in the recent 
horse. The arrangement of the enamel is similar to that in the latter, and is 
but little more complex than usual. 

Fig. 9 represents a last lower molar, and Fig. 10 a fifth lower molar. These 
present nothing peculiar distinguishing them from the corresponding teeth of 
the recent horse. 

Fig. 11 represents a second or third upper molar of the right side. The 
specimen was found liy Dr. Thomas H. Streets, in a gully of Galveston Bay, 



Texas, and prosoiited hy him to llic Academy of Philadelphia. In the eom- 
plexity of lijlding oi" the enamel, as seen on the triturating surl'aee, this looih 
is quite characteristic of Eguus comjdicatus. 

Fig. 12 represents a first lower temporary molar, one of tlie specimens from 
the asphaltum-bed of Hardin County, Texas. 

Fig. 13 represents an. upper last temporary molar, another of the specimens 
from the locality just indicated. 

Fig. 14 represents an upper molar of Equus complicatus from the " phos- 
phate-beds" of Ashley River, South Carolina. 

Fig. 15 represents an inferior molar from the same locality. The upper 
molar, in the complex condition of its enamel-folding, i§ characteristic of the 
species. The lower molar presents nothing distinctive from those of the 
recent horse. 

Teeth of horses are frequently found in the Ashley phosphate-beds, mingled 
with abundance of fossil shai'k-teetli, remains of mastodon, elephant, &c. 
Many of them are undistinguishable from those of the recent horse, but others 
in size and complexity of the enamel-folding in the superior molars are suffi- 
ciently characteristic of Equus compUcatus. 

Figs.' 16 and 17 re|)resent an upper and a lower molar, which were found 
associated with remains of mastodon at Pittstown, on the banks of the Sus- 
quehanna River, Luzerne County, Pennsylvania. . The teeth are more than 
half worn away. Their size, and a rather greater degree of complexity than 
usual in the enamel lines of the triturating surfece of the upper molar, would 
probably indicate that they belong to Equus conqdicatus. 

Measurements of the specimens, represented in-Figs. 3 to 17, and referred 
to E. compllcatits, are as follows : 

First upper molar, Figs. 3, -1.— Leugtli of crown externally, 35 lines ; antero-posterior 
diameter. 21 Hues; transverse diameter, 15 lines. 

First upper molar, Figs. 5, C— Length of crown, 33 lines; antero-posterior diameter, 
21 Hues; transverse diameter, 15J lines. . 

Lust upper molar, Figs. 1, 8.— Leugtli at antero-extermil border from end of fang, 3G 
lines; length posteriorly ,,19 lines; breadth of triturating surface, 10 lines; width, 21 
lines. 

Last lower molar. Fig. 0.— Breadth, 10.^ lines; width, 7 lines. 

Fourth or fifth lower molar, Fig. 10.— Length of crown, 34 lines; breadXh, 13i lines; 
width, 73 lines. 

U2)per second or third molar, Fig. 11.— Length of crown, 32 lines; breadth, 11 lines; 
width, 15 lines. 

First lower temporary molar, Fig. 12.— Breadth, 174 lines; width, 8 lines. 



24G 

Last vpper iemporunj molar, Fig. lo. — Bicadtli, 17 linos; width, ]0 lines. 

Ujyper second or third molar, Fig. 1-1. — Length of erown, U.j lines; breadth, 14 liues; 
width, 13 lines. 

An intermediate lower molar, Fiij. 15. — Length of crown, 134 liues ; breadth, 13^ lines; 
width, 9J liues. 

TIpi)cr molar, Fig. IG. — Length of crown, 22 lines; breadth, 13i lines; width, 14J liues. 

Loiver molar, Fig. 17. — Length of crown 22J lines ; breadth, 14| liues ; width, 11 J 
liues. 

Among a small collection of fossils from Texas, snbmitted to my examina- 
tion by Professor S. B. Buckley, there is a specimen of an npper molar tooth 
of a horse of peculiar character, represented in Fig. 18, Plate XXXIII. 
The exact locality from whence the specimen was obtained is unknown. 
The tooth is apparently a fourth or fifth of the series, and is only sufticiently 
worn to exhibit the course of the enamel layers on the triturating surface. 
The tooth is longer than in the domestic horse, and is rather narrower than 
usual in relation with its fore and aft diameter. The folding of the enamel 
defining the median lakes of the triturating surface is as complex as in Equus 
complicatus, but in a ditferent position. In the latter the folding is greatest 
on the contiguous sides of the lakes, as seen in Figs. 11 and 14, but in the 
tooth under consideration the contiguous sides of the lakes are less .folded 
than usual even in the domestic horse, while the enamel border at the inner 
sides of the lakes is folded in an unusual degree. Further, the broad inner 
peninsular fold of the triturating surface, which in the domestic horse and 
other known species has a simple oval, elliptical, or reniform outline, in this 
specimen is of extreme width, narrow, and folded at the extremities. The 
width of this inner fold or column is uniform throughout the length of the 
crown. 

The length of the crown of this tooth, without the fangs, in the entire con- 
dition has been upward of 4 inches. Its fore and aft diameter at the trit- 
urating surface is 16 lines; its transverse diameter at the middle of the same 
is 1 inch. 

Fig. 19, Plate XXXIII, represents a fragment of an ii|)per molar sub- 
mitted to my examination by Professor J. S. Newberry. It was obtained 
from the lignite-beds of Shoalwater Bay, Washington Territory. It presents 
nothing which distinguishes it from the corresponding part of the molars 
of the domestic horse. 

The length of the crown externally is 2f inches, and the fore and aft 
diameter of the trituratin"; surface is 14 lines. 



247 

HIPPARION. 

A small collection of fossils, submitted to my examination l)y Professor S. 
B Buckley, mainly consist of equine remains, of wliich the determination is 
uncertain and the near relations obscure. Most of them were obtained in 
Washington County, Texas, a few in the contiguous county of Bastrop, and 
several others in Navarro County. They were usually Ibund in digging wells, 
at the depth of from 25 to 30 feet, imbedded in a rocky stratum. Most of 
the specimens are free troui matrix, but several have attached portions of a 
hard arenaceous limestone. From the character of the fossils, I suppose the 
formation to be of contemporaneous age with that which has been called Plio- 
cene Tertiary of the Niobrara River, Nebraska, Little White River, Dakota, 
and that noticed in the preceding pages of the Sweetwater River, Wyoming. 

Fig. 14, Plate XX, represents a specimen labeled as having been obtained 
from an ossiferous rock at a depth of 25 feet, in Washington County, Texas. 
It is a last upper molar of a small equine animal, and is moderately worn' 
away at the triturating surface. It is strongly curved, and is nearly twice the 
length antero-externally that it is postero-internally. In the isolation of the 
antero-internai column from the antero-median column, as seen on the triturat- 
ing surface, it accords with the character of Hipparion. It sufficiently re- 
sembles in its relative proportions, and the complexity of arrangement of its 
enamel-folds, the fragment of a tooth, represented in Fig. 17, Plate XVIII, 
of the Extinct Mammalian Fauna of Dakota, &c., to belong to the same species. 
The latter specimen was also obtained in AVashington County, Texas, and has 
been referred to Hipparion speciosum, a species originally proposed from 
specimens discovered at Bijou Hill, Dakota, and represented in Figs. 1(1, LS 
and 19 of the work just indicated. 

The measurements of the specimen are as follows: 

Lines. 

Length of crown anfero-externally H^ 

Length of crowu postero-internally ^h. 

Breadth of crown antei'o-posteriorly ^k 

Breadth of crown transversely - ^4 

Another specimen, consisting of the middle portion of an upper molar, from 
its proportions and the folding of the enamel lakes of the triturating surfece, 
is supposed to belong to the same species. It was obtained in Navarro 
County, Texas. 



•248 

Fig. 15 represents a specimen found in associaliuii witii that oC Uic jire- 
vitins figure of" the same plate. It appears to be a tiiird or fourth up|)er 
molar, ami, IVom the size and arrangement of enamel on the triturating sur- 
liice, might be supposed to belong to the same animal as the former speci- 
mens. In the proportions of the tooth it resembles those of Merychippus 
more than it does those of Hipparion. The crown is quite short, and exhibits 
a considerable degree of curvature. It is al^out 2 lines long on the inner side, 
iind three times that length on the outer side. On the triturating surface the 
antero-internal column appears as an elliptical ring, as in Hipparion, Ijut it 
exhibits a pointed process indicative of continuity at a later period with the 
antero-median column, as in Protohippus and Merychippus. The tortuous 
enamel-line on the inner part of the triturating surface presents no median 
fold directed toward the elliptical ring, as is the case also in the fourtii molar 
of Protohij^ius, as seen in Fig. 2, Plate XVII, of the Extinct Mammaruiu 
Fauna of Dakota, &c. 

The antero-pqsterior diameter of the tooth is Tjj Hues, and its transverse 
diameter 8.^ lines. 

Another specimen, consisting of a mutilated, unworn molar, from its pio- 
p(jrtions, is supposed to Ijelong to the same species as the former. It was 
obtained at a depth of 30 feet from the surface in Washington County, Texas. 
The crown internally is 5.J lines long, and has measured externally about 10 
lines. Its breadth is 9 lines, and its transverse diameter has been but little 
less. 

PR(JTOIIIPPUS (?) s. MERYCHIPPUS? 

Among the Texan collection of fossils there are several which are suspected 
to belong to one or other of the equine genera above named. 

Fig. IG, Plate XX, represents a specimen obtained from a well, at a dciith 
of 32 feet, at Independence, Washington County, Texas. It is an upper 
molar, apparently the second or third of the series of the usual complement 
of six large teeth in equine animals. In its proportions it would appear to 
belong to the genus Merychippus rather than Protohippus. The crown is 
from 3J to 4 lines in length on the inner side, and from 7 to 8 lines on the 
outer side. The median enamel lakes of the triturating surface are of simple 
character, and widely gaping, apparently indicating but comparatively little 
wear, notwitiistanding the shortness of the crown. In the appearance of the 
triturating surface it resembles more the teeth of Piotoliippus 'peiditus, as 



249 



represented in Fig. 2, Plate XVII, of llie Extinct Mammalian Fauna of 
Dakota, &c., than it does those of Merychippus, represented in Figs. 5 and 9 of 
the same plate. On the other hand, it bears a near resemblance to the teeth 
from Little White River, Dakota, represented in Fig. 1, Plate XXVII, of the 
work just quoted, which were supposed to pertain to Merychippus mirahUis. 

Another specimen, from Bastrop County, Texas, consists of an upper molar 
with the portion internal to the median enamel lakes broken away. It is 
rather smaller than the preceding, and would ai)pear to hold the relation with 
it in the series of a fourth or fifth molar. 

A third specimen, accompanied l)y a label in the handwriting of Dr. Shu- 
mard, is marked ("Eocene,) Trinity River, Navarro County, Texas." It is a 
lower molar, represented in Fig. 20, Plate XX, and may perhaps lielong to 
the same species as the preceding. 

The measurements of the specimens are as follows: 

Lines. 

Bi-eadth of the second upper molar 9| 

Width of the secoud upper mokxr IQi 

Breadth of the fourth upper molar ' S 

Breadth of the lower molar 9 

Width of the lower molar 53 

Fig. 17 represents a specimen found in association with those of Figs. 14, 
15, at a depth of 25 feet, in Washington County, Texas. It is an upper 
molar of the right side, probably the fourth of the series. It is but moder- 
ately worn, and is imperfect at the back inner corner. In its proportions and 
degree of curvature it agrees with the teeth of Protohippus. In size and 
arrangement of the enamel it approaches in character some of those referred 
to Protohijypus placidus, represented in Figs. 39 to 48, Plate XVIII, of the 
Extinct Mammalian Fauna of Dakota, &c. 

The measurements of the specimen are as follows : 

Lines. 

Length on inner side 8 

Length at antero-external corner lli 

Breadth of triturating surface 7i 

Transverse diameter of surface 7 

Fig. 18 of the same plate represents a specimen from '"Little's Well,'" 30 
feet in depth from the surface, in Bastrop County, Texas. It is a iirst upper 
molar, and is sufKciently like the former to belong to the .same species. It 
32 G 



250 



also resembles the corresponding toolli of Fii^f. 6, Plate XXVII, of the Ex- 
tinct Mammalian Fauna of Dakota, &c., sufficiently to pertain to the same 
species. This specimen was obtained on Little White River, Dakota, and 
was referred to Protohiiipus placidus. The proportions of the former are the 
same, but, being more worn, it is shorter, and appears larger at the triturating 
surface. At the same stage of abrasion they would even bear a greater 
resemblance to each other, as the open fold on the posterior part of the Little 
White River specimen, in a more worn condition, would then form an islet on 
the triturating surface, as in the Texas specimen. 

The measurements of the specimen, in comparison witii those of the Little 
White River specimen, are as follows: 



Texas 
specimen. 



Dakota 
specimen. 



Length of crown at tbe antero-internal column.. 
Length of crown at the postero-external cohiinn . 

Breadth of crown at the triturating surface 

Width of crown at the triturating surface 



Lines. 

6 
10 

H 

7 



Lines. 
S 

9 

S 



The Museum of the Smithsonian Institution contains several specimens of 
teeth apparently of ProtoMppus perdilus and Meryckippus mirabUis, obtained 
by Mr. Clarence King in Utah. 

AXCHITHERIUM. 

AnCHITHERIUM (?) AUSTRALE. 

Among the Texan collection of fossils there is a specimen of peculiar 
character rejn-esented in Fig. 19, Plate XX. It was tbund in association with 
that of Fig. 16, of the same plate, in Washington County, Texas. It is the 
first of the series of six large upper molars as existing in equine animals, but 
exhibits in front the impress of a premolar larger than usual in members of 
the order. The specimen is broken at its outer part, but the remainder 
is nearly as characteristic as if the whole were complete. The crown is so 
worn away that the dentine is continuous upon all the constituent lobes. An 
olilique valley extends from the inner side and ends in a foot-like expansion 
near the center of the triturating surface, and l)ack of the center there re- 
mains a crescentic enamel lake. 



2.51 

The tootli i.s devoid of" eoinentuni, and resembles in its constitution the cor- 
responding one of Anchitherium nearer than it does that of other known 
equine animals. The inner and intermediate lol)es appear somewhat fuller 
than in Anchitherium, and the intermediate spaces narrower and less con- 
vergent at bottom. 

It maj' perhaps belong to Anchippus, founded on an imperfect tooth from 
the same locality, and represented in Fig. 13, Plate XXI, of the Extinct 
Mammalian Fauna of Dakota, &c. It presents important peculiarities, l)ut 
these may depend on the difierence of position of the tooth in the series. 
There is, however, one feature in the tooth of Anchippus which is absent in 
the specimen under consideration, rendering it probable that the teeth per- 
tain to different genera: The feature to which I allude consists of a con- 
spicuous fold or offset from the postero-median lobe projecting into the oljlique 
valley of the crown toward the antero-median fold. In Parahippus the same 
fold exists in a more complex condition. 

The tooth in question likewise resembles that represented in Fig. 11, Plate 
XXI, of the work above quoted, as characteristic of the genus Hypohippus, 
nearly as much as it does those of Anchitherium, and may, perhaps, belong 
to a smaller species of the former. 

In the uncertainty as to the nearer generic relationship of the specimen it 
may be regarded as indicative of a species of Anchitherium with the name 
given at the head of the chapter. Tiie species was about as large as the 
Anchitherium aurelianense of the Eocene Tertiary deposits of France. 

The estimated size of the tooth is 11 lines in diameter antero-posteriorly 
and nearly the same measurement transversely. 

Anchitherium agreste. 

During Professor Hayden's exploration in Montana, he discovered several 
fossil jaw-fragments of a species of Anchitherium. They were found in asso- 
ciation with a Helix, partially imbedded in an indurated, gray, arenaceous 
marl, and were derived from a lacustrine Tertiary deposit on Red Rock 
Creek, one of the head Ijranches of the Jefferson Fork of the Missouri 
River. 

The jaw-specimens belonged to a species considerably larger than the 
Anchitherium Bairdi of the Miocene Tertiary of White River, Dakota, and 
approached in size (lu,^ A. aurelianense of the Pliocene Tertiary of France. 



252 

The teetli in the specimens, as represented in Figs. IG, 17, Plate VII, are 
considerably worn, but retain their anatomical characters snfHciently to show 
that they are identical in form with those of the two species just named. 
They nearly accord in size \\'ith the mutilated upper molar, represented in 
Fig 5, Plate II, from Oregon,' referred to Anchitherium Condom. In the doubt 
whether the latter is really a true species of the genus in which it has been 
placed, the lower-jaw fragments in cpiestion are regarded as representino- a 
species with the name heading the chajiter. 

Measurements from the specimens are as follows: 

Lilies. 

Space occupied bj' tbe back four molars 34 

Space occupied by the back three molars 27 

Fore and aft diameter of last premolar .... , S 

Transverse diameter of last premolar G4 

Fore aud aft diameter of first molar 73 

Transverse diameter of first molar 7 

Fore and aft diameter of last molar 11 

Ti'ausverse diameter of last molar 5a 

Anchitherium (?) . 

In digging a well at Antelope, Nebraska, in the summer of 1868, at the 
depth of 60 feet a stratum was found which was stated to be remarkable 
for the number of fossil-bones it contained. The relative age of the stratum 
has not yet been ascertained, but from the character of the fossils it is sus- 
pected to be contemporary with the Mauvaises Terres formation of White 
River, Dakota, or perhaps with the later formation of the Niobrara River, 
Nebraska. From among the specimens collected at the time, my friend Dr. 
John L. Le Conte obtained a coronary bone of a small equine animal, which he 
sent to me- for examination . 

The specimen was exhibited to the Academy of Natural Sciences, and is 
noticed in its Proceedings for August, 1868. Subsequently, some remains, 
apparently of tlie same animal, from the same locality were described by 
Professor Marsh in the American Journal of Sciences for October, 1868, and 
referred by him to a diminutive horse with the name of Equus parmilus. 

The specimen of the coronary bone is represented in Fig. 23, Plate XX. 
It is only a little over half the length and is considerably less than half the 
breadth of the corresponding bone of the horse, so that it indicates an animal 
of little more than half its height and of more slender proportions. Its 
size would about accord with Anchitherhan Bairdi of the White River 
Tertiary formation of Dakota. 



253 
The nieasurciiiLUits of the specimen nre as follows: 

Lill(^S. 

Lcngtli ill the axis 9 

Breadth at tTie upper extremity !) 

Thiclvuess at the upper extremity (> 

Breadth at the lower extremity 8 

Order Ruminantia. 

BISON. 

Bison latifeons. 

Remains of large oxen which were contemporaneous witli the American 
mastodon have been discovered in several parts of North America. They 
have been referred to several extinct species, but the materials have been too 
incomplete to determine the question with any degree of satisfaction whether 
they pertain to more than one. The fossils indicate individuals very greatly 
diflfering in size, but the difference is perhaps sexual rather than sjjecific: 
The more robust specimens probably belonged to males, and the smaller 
ones to females. 

The most complete specimen which the author has had the opportunity of 
examining is the cranium, retaining the horn-cores, represented in Figs. 4, 5, 
Plate XXVIII, one-fifth the natural size. It was discovered by Mr. Calvin 
Brown and his son Wilfred, of San Francisco, California, while engaged as 
engineers in the construction of the Spring Valley water-works of that city, 
and by these gentlemen was presented to the Academy ot Natural Sciences of 
Philadelphia. Mr. Calvin Brown informs me that tiie cranium was found 
in a bed of blue clay, 21 feet below the surface, in Pilarcitos Valley. 

The specimen resembles the corresponding part of the skull of the living 
buffalo {Bison mnericanus) so closely that it will be unnecessary to describe' it 
in detail. Besides being larger, the horn-cores are especially dispropor- 
tionately larger, and are more transverse in their direction, or are less inclined 
backward. The occiput appears proportionately wider and lower from the 
less degree of prominence of its summit. The latter is, however, ^\•ider, 
and is more distinctly defined from the posterior occipital surface by the 
rougher and more prominent protuberance of attachment for tlie nuchal 
ligament. The occipital foramen is no larger than in the l)uffalo., and the 
notch below, between the condyles, is more contracted. The Ibrelicad, near 
its middle, is rather more protuberant than in the bnlfalo. 



254 



Comparative measurements of the fossil with the correspoudiug part of 
the skull of a large buffalo are as follows : 



Bison 
latifrons. 



Distance between tips of horn-cores 

Distance between bases of born-cores 

Circumference at bases of born-cores 

Lengtb of born-core along lower curvature 

Breadth of forehead where narrowest 

Breadth of forehead at back of orbits 

Length of forehead from occiput to fronto-nasal suture 

Breadth of occiput 

Depth of occiput 

Breadth of condyles together 

Transverse diameter of occipital foramen 

Vertical diameter of occipital foramen 

Distance between ends of paramastoid processes 

Length of temporal fossa - - 



Indies. 
.36 
15J 
14 
Uh 
13^ 
16 
13J 
12A 

7 

6 

2 

53 



Bison 
americanus. 



Inches. 
26 
12 
11 
12 
11 

10 
10 

5 
2 

43 

4f 



The California collection of fossils, belonging to the cabinet of Wabash 
College, Indiana, contains several specimens of teeth which I suppose to 
belong to Bison latifrons. They were loaned to me for examination through 
the kindness of Professor E. O. Hovey, and are represented in Figs. 6, 7, Plate 
XXVIII. They consist of the second and third upper molars, and agree in 
constitution with the corresponding teeth of the recent buffiilo, and in size 
correlate with the skull above described and referred to B. latifrons. 

The measurements of the specimens, in comparison with those of the 
buffalo, are as follows : 





Bison 
latifrons. 


Bison 

americanus. 


Secontl upper molar : 

A iitorn-i^nsit'pririr diMTTiPtpr of t,rif,nrnt'iill<T' SUvfMfiP, 


Lines. 

11 

14 

18 
13i 


Lines. 
15 


Transverse diameter of triturating surface - 

T'i'missv'prQfi flininptpr of orown iionr l"»nsp ■ - ^ 


lOa 
123 


Third upper molar : 
Aiifpro-no<*tprior (liniiifteT of tritnratitisr surface 


15 


Transverse diameter of tritui^ating surftice 

Transverse diameter of crown near base 





255 

An isolated iippcr secuiul molar of Biison laufrons^ found in association 
with remains of Mastodon ainericanus and Equus major at Pittstown, on the 
Susquehanna River, Luzerne County, Pennsylvania, is represented in Fig. S, 
Plate XXVIII. It is considerably worn, the usual median internal fold of 
the tooth, in a less worn condition, being seen in the specimen as an 
oval islet. 

The fore and aft diameter of the specimen is 16.j lines, and its transverse 
diameter at the triturating surface I'/ lines. 

A specimen of a last inferior molar of a Bison, represented in Fig. 4, 
Plate XXXVII, and a metacarpal bone of the Megulonyx Jeffersoni, 
presented to the Academy l)y Dr. Edward D. Kittoe, of Galena, were 
obtained, together with some additional bones, from a crevice of the 
lead-bearing rocks, at a depth of 130 feet from the surface, near 
Elizabeth, Jo Daviess County, Illinois. The tooth is about the size of 
that of the recent bulfalo, and may pertain to that species, though it is not 
improbable it may have belonged to a small individual of Bison latifroiis. 

The specimen is but little worn. The length of the crown at its fore part 
is '2| inches ; its breadth 23 lines ; its thickness at the base anteriorly 10 
lines ; and near the triturating surface 7 lines. 

AUCHENIA. 

AUCIIENIA HESTERNA. 

In the Proceedings of the Academy of Natural Sciences for 1870, page 
125, the writer described some fossil remains from California, submitted to 
his inspection by Professor J. D. AVhitney. Among the fossils were several 
which were attributed to a large extinct llama, with the name of Auchenia 
californka. The specimens upon which the species was founded consisted 
of a metacarpal l)one, the fragment.of another, the proximal end of a femur, 
an acetabulum, and portions of a tiliia. The species indicated was much 
larger than the camel, as the head of tlie femur is 3 inrlios in diameter, and 
the metacarpal is 19 inches long, whereas the latter in the camel is but 13 
inches long. 

In the Philosophical Transactions of London for 1870, Professor Owen 
has described some remains of a large extinct llama from Mexico, under the 
name of Palauchcnia magna. This animal approximated in size the camel, 
whereas the remains attributed to Auchenia californica much exceeded it. 

Of the remains referred by Professor Owen to Palauchenia, there is a 



256 

series of" molar teeth described and figured from casts and photographs. The 
teeth are considered as pertaining to the lower jaw, but from a view of the 
figures I cannot avoid the suspicion that they really belong to the upper jaw. 
In the form and proportions of the molars, but especially in the form, consti- 
tution, and number of the premolars, the series appears to me to resemble 
more the upper one of the camel and llama than it does the lower one. In 
one respect one of the molars, the last of the series, approaches in character 
the last lower molar of the camel and llama. • This is in the possession of a 
fifth lobe, which is, however, much less well developed than in the latter 
animals. If the view I have taken is not erroneous, Palauchenia, so far as 
we know it from its remains, would not present sufficient distinctive char- 
acter to be regarded as of a different genus from Auchenia. 

Among the collection of fossils from California, belonging to the cabinet 
of Wabash College, Indiana, tliere is a well-preserved series of lower molar 
teeth, represented in Figs. 1, 2, Plate XXXVII. These, from their size and 
constitution, would appear to belong to a species of llama exceeding in size 
not only the existing llama, but also the camel and the Palauchenia. 

The question at once arises whether these teeth belong to Auchenia cali- 
fornica, Palauchenia magna, or to a third species. 

The proportions of the bones upon which the former was founded indicate 
an animal one-third larger than the camel, but the teeth above noticed might; 
belong to an animal but little exceeding a large camel or the P. magna. If 
the characters assigned to the latter as a genus are correct, it is clear that 
the series- of teeth from California do not belong to the same animal, and tliey 
then could only pertain to a small individual of Auchenia callfornica, or to 
another species rather larger than the existing camel. Under the circum- 
stances, until further light is thrown on the subject by the discovery of addi- 
tional material, we may suppose that two large species of llama, perhaps" 
exclusive of Palauchenia magna, were once inhabitants of the western por- 
tion of the North American continent, contemporaneously with the Mastodon 
americanus. One of these species, a third larger than tlie existing camel, is 
the Auchenia californica ; the second, intermediate in size to the two latter, 
may be named A. hesterna. . 

The teeth in question indicate an animal which had arrived at .maturity. 
While the first molar, which earliest acquired its functional position, is much 
worn, the last molar has its fifth lobe unabraded, and the pi-emolar has but 
partially lost its summit. 



257 



The molars sliow no cliaracteristic differences t'roni tliose of the llama and 
eamel. The narro\\' told seen projecting outwardly in advance of the antero- 
external lobe of the last molar, and in a less degree in the second molar, in 
the llama, is nearly obsolete in the fossil. 

The premolar presents some difference from the corresponding tooth *in 
the llama. The crown is thickest, and is romided behind, and it narrows 
lbr\\ard to the anterior subacute border, which is convex longitudinally, and 
is thickened toward the bottom. The outer side is not impressed at the back 
part, as in the llama, and is feebly impressed at the fore and upper part. The 
inner side also is but moderately impressed along the middle, compared with 
its condition in the llama. A deep enameled pit occupies the inner back part 
of the crown, penetrating from the triturating surface, as in the latter. The 
pit opens backward for a considerable portion of its depth, and is closed in 
this position by apposition with the succeeding tooth. 

The measurements of the teeth, in comparison with those of the camel 
and llama, are as follows : 



Fourtfi premolar: 

* Breadth of crovcu where greatest 

* Width of crown where greatest. . 
Length of crown to origin of fangs. 



■ First molar : 
Breadth of triturating surface. 
Width of triturating surface . . 
Length of crown 



Second molar: 
Breadth of triturating surface. . 
Width of triturating surface . . . 
Width of crown where greatest. 
Length of crown 



Third molar : 
Breadth of crown where greatest. 
Width of crown where greatest . . . 
Length of crown 



Aucheuia 
hesterna. 



Lilies. 

13 

G 

20 



20 

lOi 

20" 



20 
10 



ai 

10 

41 



Aucbonia 
lauia. 



Camel. 



Lines. 



•J.-i 



Lilies. 



12 



3 


7 


G 


14 


7 


18 


5 . 


9 


5 


5 


9 


23 


5| 


10 


5^ 


10 


G 


IG 


3 


28 


h.L 


10 


7 


17 



* For brevity I bave iised breadtb for tbo antero-posterior diameter, and width for tlio trausverso 

diameter. 



33 cf 



258 



The length of the sei'ies of lower inoLais and premolars together, in the 
clitFerent species, is as follows : 

Lines. 

LcTigtU of tbe series iu the llama 32 

Length of the series in the camel C(i 

Length of the series iu the Auchenia hesterna 84 

Accompanying the inferior molar specimens from California there is a 
specimen of an upper molar represented in Fig. 3, Plate XXXVII, which, 
from its constitution and size, is supposed to belong to the same species, if 
not the same individual. 

It is a first or second true molar of the left side, and closely resembles tlie 
corresponding teeth of the llama. 

Its comparative measurements are as follows : 



Second upper molar. 


Llama. 


Camel. 


Auchenia 
besterua. 


Palauchenia 
magna.* 


Breadth of the triturating surface 


Lines. 

8 

8 


Lines. 
20 
11 
13 
10 


Lines. 
23J 
12 

29 


Lilies. 
21 


Width of the triturating surface 

Width of crown near base 


11^ 


Length of crowu 


lOJ 





"Professor Owen's measurements giveu as those of the secoml lower molar. 



PROCAMELUS. 

The genus Procamelus, or Protocamelus, was originally named from remains 
discovered by Professor Hayden, in the Tertiary sands of the Niobrara Eiver, 
Nebraska. Three species were indicated from tlie locality under the names 
of Procamelus rohustus, P. occidentalism and P. gracilis. The specimens show 
that Procamelus possessed a series of four premolars and three molars to the 
lower jaw, from which we may infer an equal number to the ujiper jaw. The 
molars and last premolar have the same form as those of the camel. 

Among the Texan collection of fossils, loaned by Professor Buckley, there 
is a specimen of a tooth supposed to belong to Procamelus. It is repre- 
sented in Fig. 21, Plate XX, and was found in association with the equine 
teeth before described, and represented in Figs. 14, 15, and 17 of the same 
plate. It is a first or second upper molar, and sufficiently resembles the 
corresjiftnding tooth of P. occidentalism as we may suppose it would appear in 



259 

the same stage of wear, as to render it probable tliat it may Ijelong to. the 
same species. 

The tooth is much worn, leaving two narrow crcscentic enamel pits in the 
middle of the triturating suriace. No trace of an internal column or tubercle 
e.xists in the interval internally of the inner lobes of the crown. 

The specimen measures 11 lines antero-posteriorly, and nearly the same 
extent transversely. 

Fig. 22 represents an astragalus found in association with the molar tooth 
just described, and probably belonging to the same animal. It has nearly 
tlie size and form of those of the common deer, but is proportionately a little 
longer and narrower. 

Another specimen in the same collection consists of a cubo-navicular bone 
of a ruminant a fourth smaller than the common deer. It was found in asso- 
ciation with the equine tooth above described, and represented in Fig. 16, 
Plate XX. 

An additional specimen consists of a last lumbar vertelri'a, a])parently of a 
ruminant. It was obtained in Washington County, at a de[)th of 30 feet, 
from a hard arenaceous limestone. It is white in color, crushed downward, 
and has a portion of the matrix adherent. The vertebra has nearly the size 
and form of the corresponding bone of the camel, and tnay have pertained to 
the largest species of Procamelus, named P. rohustus. 

Procamelus virginiensis. 

I may here indicate the recent discovery of some remains, apparently of a 
species of Procamelus, in the Miocenj3 Tertiary formation of Virginia, the 
first which have yet been noticed of the family in any locality east of the 
Mississippi River. 

Mr. C. M. Smith, of Richmond, Virginia, while engaged in excavating a 
tunnel beneath the city, discovered a number of bones and teeth, which he 
has loaned to me for investigation. They were found imbedded in blue clay 
containing numerous infusorial remains, among which the beautiful frustules 
of a Coscinodiscus are especially conspicuous. The fossil-bones mainly 
consist of those of cetaceans and fishes, but among them are a few of 
land-animals, and also a portion of a humerus of a Inrd. The forma- 
tion from which the fossils were derived is proliably an estuary deposit of 
Miocene age. Among the fossils there are several tcetli, which arc sup- 



260 

l)ose<l to belong to a species of Procainelus. The spcciiiieiis, consisting of a 
last premolar, aud the first and last molars of the lower jaw, are represented 
in Figs. 26 to 29, Plate XXVII. The teeth have the same form and consti- 
tution as those of the western species of Procamelus above named, and they 
appear to indicate an additional species, which was about the size of the ex- 
isting llania, and intermediate in size to P. occldcntaHs and P. graciUs 
The measurements of the teeth are as follows : 

LiiR's. 

Autero-posterior diameter of last premolar 7 

Transverse diameter of last jiremolar 4 

Anteroposterior diameter of first molar 7;^- 

Transverse diameter of first molar (] 

Anteroposterior diameter of last molar ll'i 

Transverse diameter of last molar 

MEGxVLOMERYX. 
Megalomeryx niobrarensis (?) 

The genus to which the above name was applied has not been determined 
by ])()sitive characters, and may prove not to be distinct from Procamelus. 
It was i)roposed on two specimens of teeth of a large ruminant, apparently 
of the camel family, discovered by Professor Hayden in the Pliocene Tertiary 
sands of the Niobrara River, Nebraska. The teeth, both lower molars, are 
described in the " E.\tinct Mammalia of Dakota and Nebraska,'' page 161, and 
are represented in Figs. 12-14, Plate XIV, of tliat work. 

•A similar tooth was submitted to my examination, by Professor J. D. Whit- 
ney, fi-om the Pliocene Tertiary of Tuolumne County, California. 

Figs. 24, 25, Plate XXVII, represent a mutilated lower molar, apparently 
(d'the same species. This was found in L'Eau qui Court County, in Northern 
Nebraska, and was presented to Swarthmore College by George S. Truman. 

H E L N I A . 

EMYS. 

Emys petrolei. 

An extinct species thus named is indicated l)y a number of fragments of 
several turtle-shells, which were found in association with remains of Masto- 
don, Megalonyx, Equus, Tnicifrlis fafalis, &c., in Hardin County, Texas. 
They were ol^tained I'roin a stratum of clay beneath a bed of bitumen, and. 




261 

lik(! must of IIr' otliLT i'ostiiLs aecoinpauyiiig them, are tliuroiighl}- saliiratcd 
with bitumen. 

Tiie most characteristic specimens consist of two isolated cpisterna, repre- 
sented in Fig. 7, Plate IX. They indicate an animal al)()ut tin? size of the 
recent Emys scabra of the Southern States, but the hones are proportionately 
more robust tlian in that species. They abruptly project in advance of the 
lateral grooves defining the gular scutes, antl are squarely Iruneate'd. Tiie 
upper gular surface is nearly square, and slopes forward to an acute edij:e. 
In one specimen it is wider fore and aft than transversely; in the other rather 
less. Behind the gular surface, the bone is deeply hollowed into a concavity. 

The measurenients of the specimens are as follows : 



Wkltli of episternal at the front bonlor ... I 10 

Length of internal border 11 

Leugtli of po.stero-lateral border 12 

Greatest thickness of tlie bone j 5J 

A hyposternal bone about the middle is 28 lines fore and aft, 26 lines wide 
behind the inguinal notch, and half an inch where thickest internally. 

The fore part of a nuchal plate of the carapace resembles the corres|)on(l- 
ing portion in Emys scabra, but is more deeply indented. Its width in IVont 
is an inch; the length of its median ridge is 10^ lines; and its thickness where 
greatest is half an inch. 

FISHES. 

The following species of extinct fishes were first described by the writer 
in the Proceedings of the Academy of Natural Sciences of Philadelpliia iiir 
June, 1870. Tiie specimens were borrowed for my examination from a 
gentleman ot New York, by my friend Mr. George N. Lawrence, of the 
same city. The locality of the specimens was not ascertained other than 
that they came from the Rocky Mountains. They were accompanied with 
some shells, evidently of the later Tertiary period, and also with a coronary 
bone, apparently of Equus exceisiis. The fish-rcmains consisted of eight 
detached i)haryngeal bones of a cyprinoid. and a single dermal bone of a ray. 

Subsequently, while a notice of these fossils was in press, the writer 
received from Professor Hayden a pharyngeal bone of the same species and 
ap[>earauce as the Ibrmer, which was labeled "Castle Creek, Idaho." 



2(32 

More recently, Prulbssor J. S. Newberry sent to me a small collection of 
fossils, among which were seven additional specimens of pharyngeal Itones, 
identical in appearance with the former, which were stated to have been 
fonnd at Castle Creek, Idaho. 

Later, Professor Cope described, in the Proceedings of the American 
Philosophical Society, a number of species and genera of extinct cyprinoid 
fishes from Catharine's Creek, Idaho. Among these he indicates the same 
species as that to which the above-mentioned pharyngeals have been 
attril)nted, and which have been referred to a previously undescribed genus, 
as follows : 

Family Cyprinidce. 
MYLOCYPRINUS. 

MvLOCYPfilNUS EOBUSrUS. 

The specimens, consisting of detached pharyngeal bones with teeth, from 
which the genus and species were oi'iginally described, were all imperfect. 
Having attempted the description without a previous comparison with the 
corresponding bones of a recent cyprinoid, I find I have been so careless as 
to have described them in an inverted position. The specimens later received 
are better preserved, and among them are five complete ones. All the 
specimens together exhibit such a variety in size and detail as to lead one to 
suspect they may- represent sevei'al different species, though I view them as 
belonging to a single one, the diiferences being, as I suppose, mainly due to 
a difference of age. Six specimens, from Professor Newberry's collection, 
are represented, of the natural size, in Figs. 11 to 17, Plate XVII, all of them, 
excepting Fig. 16, being views beneath with the back part directed upward. 
Fig. IG represents an inner view, exhibiting the masticatory surfaces of the 
teeth. 

The principal i-ow of teeth consisted of five, as may be seen by the organs 
themselves and their remains in Figs. 11 to 14, inclusive. They are all of 
the true masticatory type, and are directed inwardly, opposed to those of th(; 
other side. Tiic first and last of the series are the smallest, and the inter- 
mediate ones are comparatively large. 

In the smallest specimens, and the youngest, as I suppose them to be, the 
second tooth is the largest, and from this they .successively decrease in size 



263 

to the last, as seen in Fig. 13. In tlie largest and oldest specimens, tiie in- 
termediate three teeth are nearly equal in size, as seen in Figs. 16, 17. In 
the specimens of intermediate size and age we notice some irregularity, hut 
generally a disposition to increasing uniformity of size in the corresponding 
teeth. 

The first tooth is directed backward toward those behind; the otliers are 
parallel in their direction inwardly. 

The crown of the terminal teeth is more mammillary than in the interme- 
diate ones, in which it is oval with the longer diameter directed from above 
downward, and the short diameter fore and aft. The masticating surface of the 
teeth is broad, oval, moderately convex, sometimes nearly flat, and usually 
slightly depressed at the middle or at the center. The crowns resemble 
strikingly those of worn human premolars, and are covered by tliick, smooth 
^nameloid substance. 

The teeth are supported on strong bony columns as long as the crowns 
They project from the lower ramus of the pharyngeal below tlie position of 
the upper or postei'ior ramus. The last of the series projects backward and 
inward from the conjunction of the two branches, as usual in cyprinoids. 

In the older specimens, it would appear that the first tooth of the series 
was after a certain time not replaced. 

Most of the specimens present evidences of the existence of two minute 
teeth forming a secontl row above the principal one. 

The pharyngeal bones, in accordance with the strong crushing teeth they 
sustain, are stronger than usual in the ordinary living carp-like fishes. 

The pharyngeal bone is widest opposite the larger teeth. The oblique 
surface directed forward and outward exhibits the usual deep hollows extend- 
ing to the bases of the teeth, or through the bone in some cases when the 
latter are absent or shed. The posterior and inferior surfaces are flat, and 
transversely striated, or, in the older ones, more or less strongly ridged. The 
anterior border is vertically concave. The external border, acute below and 
obtuse behind, is unusually thick. The inner border, extending backward 
beyond the conjunction of the two branches of the bone, is that wliich sus- 
tains the teeth. 

The upper or posterior ranuis is- comparatively short, bent forward and 
inward, and ends in a p(jint by which it was suspended from tlie occiput. 
The extremity of (he louiT or anterior ramus, extending in advance of the 



264 



teeth, ends in a triangular process vvitli a lozeuge-like articular surface Ibr 
symphysial attachment with the bone of the opposite side. 
Measurements derived from seven specimens are as follows: 



. Measurements. 


Spec. 1. 


Spec. 2. 


Spec. 3. 


Spec. 4. 


Spec. 5. 


Spec. 6. 


Spec. 7. 


Leiigtli of .series of five teeth , . . . 


Lines. 


Lines. 


Lines. 


Littcs. 


Lines. 

73 

G 

54 

11 
2i 

2 

^ 
2 


Lines. 

7 

G 

1 

2i 
2 
2 
1* 


Lines. 


Leugtli of series of four teetbj exclud- 


15* 

12 


12 
10 


8 


9 

7 


5 


Length of series of intermediate three 
teeth 


4 


Leugth of series of anterior three teeth. 




Lone" diameter of crown of first tooth . . 












Long diameterof crown of second tooth. 
Short diameter of crown of second tooth. 
Long diameter of crown of third tooth . 
Short diameter of crown of third tooth . 
Long diameter of crown of fourth tooth. 


4| 

3| 

5 
3J 


H 

H 

3 
3 

20* 

12.J 


2J 

H 

22 
4 

2i 


3 

2.r 

H 

2i 

3" 



2i 

IS 
li 
•14 

1 


Short diameterof crown of fourth tooth. 






Long diameter of crown of tifth tooth . 






1 


Short diameter of crown of fifth tooth . 












a 


Length of lower branch from back of 
iiharvniieal. 


24* 

17* 
14 


17 

lU 
10 


IG 

11 
9 


14 
10 


11 

8 


lOJ 


Depth of upijer branch to bottom of 
pliaryngeal 


Widtli of pharj'ngeal iuferiorly 


7 



Estim.ated. 



Family Raice. 

ONCOBATIS. 

Oncobatis pentagonus. 

An extinct ray, before alluded to, is indicated by a single dermal Ijone, of 
which two views are given, of the natural size, in Figs. 18, 19, Plate XVII. 
The bone has a pentagonal outline with curved margins, with the under or 
inner surface strongly convex and smooth. The upper or free surface presents 
five sloping planes more or less well defined by prominent borders. Less 
lliaii half the extent of the external surface at the center is occupied by an 
areola of thin enameloid substance which is smooth and shining nnd marked 
with concentric lines. The summit of the lione, in the center of the areola, 
l)rojects as a point of harder and more translucent osseous substance. 



The measurements of the specimen are as follows: 

Lines. 

Greater diameter of the dermal bone , IG 

Shorter diameter of the dermal bone 15 

Thickness from summit 8 

The many more fossil-remains of fishes from the Tertiary formation of 
Idaho, described by Professor Cope, he attributes to two additional species 
of Mylocyprinus, seven species of four other genera of Cyprinidse, and a 
species of Salmonidse. Fossil-shells described by Mr. Meek from the same 
formation, as well as the cyprinoid fishes, indicate a fresh-water deposit. The 
presence of a ray may probably indicate an easy communication with salt 
water. 

34 G 



DESCRIPTION OF REMAINS OF REPTILES AND FISHES FROM 
THE CRETACEOUS FORMATIONS OF THE INTERIOR OF THE 
UNITED STATES. 



The Cretaceous formation in the interior of the United States covers an 
area reaching southerly into Texas, and extending over a large portion of tiie 
eastern slope of the Rocky Mountains, northerly along the region of the 
Upper Missouri River to its sources. Exposed to viisw over a great extent 
of this area, a still larger portion underlies the vast Tertiary deposits of the 
country, Its thickness ranges from 800 to 2,500 feet, and it consists of 
various colored strata of indurated clays and sandstones, and indurated marls 
and limestones. So far as known, most of them are of marine origin, and 
contain an abundance of characteristic fossils. Some of the strata con- 
tain remains of terrestrial plants, proving that the country in the vicinity of 
the great Cretaceous seas was clothed with forests resembling, in the generic 
characters of the trees, the forests of our own time. Species of sweet-gum, 
poplar, willow, biroh, beech, oak, sassafras, tulip-tree, magnolia, maple, and 
others have been described from the fossils. With such a vegetation we 
would expect the contemporaneous existence of some forms of mammalian 
life, but as yet, in these as well as in other Cretaceous deposits of the world, 
no remains of mammals have beeu discovered. We are, however, still on 
the lookout for some lacustrine or river deposit of the Cretaceous era which 
perhaps will reveal early forms of mammals — forms which may more nearly 
relate the mammal with the reptile than any now known to us. 

Remains of birds have been found in the Cretaceous formation of Kansas, 
and have been described by Professor Marsh. Two genera indicated by him 
under the names of Ichthyornis and Apatornis are the most I'emarkable of 
their kind, and may be viewed as tbe most interesting and important paleoii- 
tological discovery yet made in the West. They have biconcave vertebivne, 
and the j^ws are furnished with teeth. Like the Archeeopteryx of the Solen- 
hofen limestone, they make the relationship of birds to reptiles much nearer 
than appears among existing forms. 



267 

111 remains of reptiles and fishes the western Cretaceous formation abounds. 
Many of these have been described by Professor Cope and Professor Marsh. 
Araoiiir the reptiles are some of the largest and most wonderful of their kind, 
represented by great turtles allied to Atlantoclielys ; numerous species of 
Mosasaurus and closely related genera ; the Polycotylus and the long-necked 
Discosaurus allied to Plesiosaurus ; and Pterodactyls, with an enormous 
expanse of wings. 

The following pages contain descriptions of remains of reptiles and fislies 
which have come under tlie observation of the author mainly from the west- 
ern Cretaceous deposits. A few of the remains are doubtful as to the forma- 
tion from which they have been derived, but are believed to be Cretaceous 
fossils. As intimately related with the western Cretaceous fossils, descrip- 
tions of a few others are included from eastern localities. 

Most of the fossils were submitted to the examination of tlie author by the 
Smithsonian Institution, and form part of a collection from the Smoky Hill 
River, Kansas, and from the Indian Territory, presented to the Army Medical 
Museum of Washington by Di-. George M. Sternberg, United States Army. 
Others from the Smithsonian Institution were collected in the vicinity of 
Fort McRae, New Mexico, and were presented to the Army Medical Museum 
by Dr. W. B. Lyon, United States Army. Many of the fossils were collected 
during the explorations of Professor Hayden. The remainder form part of 
the Museum of the Acadeiny of Natural Sciences and Swarthmore College, 
or have been contributed by Dr. William Spillman, Dr. John L. Leconte, 
Professor George H. Cooke, William M. Gabb, George II. Truman, and 
others. 

REPTILES. 

Order Dinosauria. 
POICILOPLEURON. 

POICILOPLEUKON VALENS. 

During Professor Hayden's expedition of 1869, a fossil was given to him 
as a " petrified horse-hoof" The specimen was found in Middle Park, Col- 
orado, and according to Professor Hayden was probably derived from a forma- 
tion of Cretaceous age. Similar specimens were reported not to be uncommon, 
and were known as above designated. Indeed the writer has seen a second 
specimen, which was also called a fossil horse-hoof, but unfortunately liis 
notes in relation to it have been mii-laid. 



2G8 

The fossil in question consists of one-half of a vertebral body as repre- 
sented in Figs. IG to 18, Plate XV. When resting upon the articular face, 
it is not surprising that it should have been taken tor a '' petrified horse- 
"hoof" by those not conversant with anatomy. 

The vertebral body in its entire condition would resemble in form those of 
Megalosaurus, and in shape and other characters resembles those of Poicilo- 
pleuron Bucklandi. This is an extinct reptile, from the Oolitic formation of 
Caen, Normandy, described by M. Deslonchamps ; and remains apparently 
of the same animal, from the Wealden formation of Tilgate, England, have 
been noticed by Professor Owen. It has been viewed as a crocodilian, and 
is estimated to have been about 25 feet in length. 

The Colorado fossil would indicate an animal approximating 40 feet in 
length. 

One of the most remarkable characters of Poicilopleuron is the presence 
of a large medullaiy cavity within the bodies of the vertebrae, as well as in 
the long bones of the limbs. Among living animals I know of a similar con- 
dition in the vertebrae of none except in the caudals of the ox. This curious 
"feature is a striking one in the Colorado fossil, as represented in Fig. 18. 
The lower two-thirds of the body appear occupied hy a large cavity, crossed 
by a few osseous trabeculse. The cavity is bomided by a thick lateral and 
inferior wall of compact substance, resembling that of the shaft of the long 
bones of most mammals. The wall is about 2 lines thick, and thins away 
at the upper part of the body where this is occupied by the ordinary spongy 
substance. The latter extends into the abutments of the neural arch, and is 
here more dense in character. The cavernons structure of the fossil is filled 
with crystalline calcite. 

The estimated length of the vertebral body is about G inches. At the sides 
and beneath it is much constricted or narrowed toward the middle. The 
transverse section approaching the latter position is vertically ovoid, with the 
lower and narrower end forming an acute angle. 

The articular end of the specimen, Fig. 16, is moderately depressed its 
greater extent, most so above and becoming more superficial below. Its 
upper border overhangs the deepest portion of the surface ; the lateral bor- 
ders are obtusely rounded, and widen below in a strongly convex ledge, prob- 
ably for the accommodation of a chevron bone. The bi'eadth of the articular 
surface is nearly 4 inches ; Its vertical extent a little over that measurement. 



270 



The abuliuents of the iieurul arch are tirraly co-ositied wilh the body, but 
tlieir SLitiiral connection is plainly visible. Just l)elow the suture, the side of 
the body presents a concavity. The beginning of a groove or narrow con- 
cavity is also seen extending forward beneath the body. The lateral surfaces 
of tlie specimen are smooth, excepting near the everted articular border of 
(he body, where they are roughened for the firmer attachment ot ligaments. 

Poicilopleuron was probably a semi-aquatic Dinosaurian, an animal equally 
capalile of living on land or in water, and perhaps spending most of its time 
on shores or in marshes. Whether the cavernous structure- of its skeleton 
was related to pneumatic functions, as in birds, flying reptiles, and some 
others, or whether it was only occupied with ordinary marrow, is a question 
that appears uncei'tain while our knowledge of the skeleton itself is so 
incomplete. 

Order Clielonia. 

Among Dr. Sternberg's collection of fossils from the Smoky Hill River, 
Kansas, there are several which appear to be the limb-bones of a turtle. 
Similar bones from the Cretaceous formal ion of New Jersey and Mississippi' 
I formerly attributed to species of Mosasaurus, but the recent discoveries of 
characteristic portions of the skeleton of this and allied animals, retaining 
the limbs, have proved that view to be erroneous. 

A huge turtle, represented" by the proximal extremity of a humerus ibund 
in the green sand of New Jersey, was named by Professor Agassiz Atlan- 
tochelys Mortoni. Professor Cope has described some remains of a species 
nearly as large as the former, from Kansas, under the name of Protosfega 
gig'is; and an arm-bone of a smaller turtle, from the Cretaceous formation 
of Mississippi, he has referred to a species with the name of P. tuberosa. 
Remains of a turtle, about the size of the Mississippi snapper, from Kansas, 
he has attributed to another genus with the name of Cynocerciis incisus. The 
specimens of limb-bones above mentioned, and represented in Figs. 17 to 21, 
Plate XXXVI, are not large enough to pertain to the smallest of the three 
species of Atlantochelys indicated, but would sufficiently relate in size with 
the remains of Cynocercus incisus to belong to that animal. 

The bones appear unusually flat, but this condition, in part at least, is due 
to compression. 

Fig. 17, Plate XXXVL represents the upper extremity of a luuncrus 




270 

extencling to the commencement of the distal expansion of the shaft. It 
resembles nearly the corresponding })ortion of the humerus of the snapper 
completely flattened, or a miniature of that of Atlantochelys in the same con- 
dition. The greater tuberosity appears to spring from above the top of the 
head externally, so that its upper anterior border looks like an extension of 
the articular surfiice of the latter. A strong muscular impression is situated 
upon the inner fore part of the shaft. The lesser tuberosity projects poste- 
riorly, and ends in a thick, roughened, convex surface. 

The breadth of the specimen between the two tuberosities obliquely meas- 
ures 33 lines ; the breadth of the shaft, where narrowest, is 10 lines. 

Fig. 18, represents a complete femur, apparently from the same individual 
as the former. As in the snapper and Trionyx, it is of proportionately less 
breadth than the humerus. It is apparently much flattened by pressure, so 
as to differ considerably from its exact original form. The trochanters appear 
I'elatively to have been as well developed as in the snapper, and the distal 
articulation may be supposed to have had nearly the same form. 

The length of the femur is 64 inches. The breadth of the upper ex- 
tremity is 20 lines, of the lower extremity 16 lines, and of the middle of 
the shaft 7 lines. 

Several additional bones accompanying the former appear to belong to the 
shoulder of the same animal. 

Fig. 19, represents what appears to be a portion of the left scapula with its 
upper end and the prge-coracoid prolongation broken away. The specimen 
appears distorted and flattened from its normal condition as the result of 
pressure. 

Fig. 20, represents what appears to be a portion of the coracoid bone of 
the same side, also somewhat distorted by pressure. 

Fig. 21, represents another bone-fragment, apparently from the same indi- 
vidual, which I cannot determine to my own satisfaction. Like the other 
specimens, it appears flattened from its normal condition. 

Order Mosasauiia. 

Large, extinct, marine saurians, most nearly ccHistructed as in Lacertilians, 
but having limbs constructed as paddles for swimming. The relations of these 
reptiles with the serpents, as suggested by Professor Cope, in his Synopsis of 
the Extinct Batrachia, Reptilia, &c., have been much reduced by the subse- 



271 

quent discoveries of Professor Marsli ; and tlicy appear hardly sufficient to 
justify the name of Pytlionomorplia. 

Tlie remains of mosasauroid reptiles are comparatively aljundant in the 
Cretaceous formation of the United States. The specimens collected have 
formed the basis of a multitude of species and genera, the number of which 
will probably be somewhat reduced on more careful study and comparison of 
the materials. 

In the description of the few mosasauroid remains which have been sub- 
mitted to my examination, I have referred them to species for the most part 
as recently named by Professor Marsh, who, with the rich materials in his 
jjossession, has the best opportunity of determining their generic and specific 
characters. 

TYLOSAURUS. 
Tylosaurus dyspelor. 

Among the fossils submitted to my examination by the Smithsonian Insti- 
tution, there are some bones of a large mosasauroid animal, collected by Dr. 
W. B. Lyon, United States Army, in the vicinity of Fort McRae, New Mexico. 
They consist of vertebra?, mostly more or less crushed and otherwise muti- 
lated, and a few limb-bones, and were ol)tained from a stratum of soft, yel- 
lowish chalk. Specimens from the same collection and skeleton were de- 
scribed by Professor Cope, and referred to a species with the name of Liodon 
dyspelor. This was subsequently referred to a genus, by Professor Marsh, 
with the name of Rhinosaurus, which, being pre-occupied. Professor Cope 
proposed that of Rhamphosaurus, and, as this also was previously approjiri- 
ated, Professor Marsh has now proposed the name of Tylosaurus. 

Of the specimens selected by me for examination half a dozen consist of 
centra and parts of others of posterior dorsal vertebras, most of which are 
remarkable for tha extent of compression they have undergone with little 
appearance of fractures. They look as if they had been in a plastic condi- 
tion, and in this state had been flattened from above downward. 

In three of the specimens, consisting of posterior halves of dorsal centra, 
the articular ball presents a iialf oval outline below, with slanting sides above, 
and an emarginate summit. The measurements of the ball, indicating a suc- 
cessive increase in the degree of flattening in the three specimens, arc as 
follows : 



272 

Liucs. 

Depth of specimen represented in Fig. 1, Plate XXXV , 44. 2 

Breadth of specimen - CO. 

Depth of second specimen 42. 

Breadth of second specimen 01. (J 

Depth of specimen represented in Fig. 2 39. 8 

Breadth of specimen 63. 

In the other three sijecimens, consisting of nearly complete dorsal centra, 
and measuring about 4J inches in Jength, the compression is still greater. 
In one of the specimens the distal articulation, represented in Fig. 3, is so 
flattened as to appear transversely lenticular in outline and emarginate above. 
It measures 30 lines in depth and 62J lines in breadth. 

Seven selected specimens consist of caudals which have mostly undergone 
little or no compression. They all pi'esent beneath a pair of strong processes 
projecting obliquely backward from nearer the posterior part, and excavated 
ill a conical pit directed backward and downward for articulation with chev- 
rons. Three have been provided with strong diapopliyses projecting in 
advance of the middle and nearly half way up the sides. A fourth specimen 
has a small, narrow diapophysis projecting in advance of the middle and 
about two-thirds up the sides. The remaining two vertebrae have no dia- 
popliyses. 

The caudals with diapopliyses have the articular ends of the body trans- 
versely oval, witli a slightlj' hexahedral outline, emarginate above, and in a 
less degree below. Tliose without diapopliyses have the articular ends of 
proportionately less width, of less hexahedral outline, and not emarginate 
below, so that they appear more cordiform than oval. 

The largest caudal with diapophyses has measured as follows : 

Lines. 

Estimated length of centrum beneath 37.5 

Estimated breadth of articular ends 48. 

Depth of articular ends 42. 

A smaller caudal with diapophyses, less mutilated, and represented in Figs. 
4, 5, measures as follows : 

Linos. 

Length of centrum beneath 28. 5 

Breadth of articular ends 44. 

Depth of articular ends , , 40. 

The caudal with small diapophyses, represented in Figs. 6, 7, measures as 
follows : 



273 

Liues. 

Length of centrum bcueatli .'><>. 

Breadth of articuhir emls tO. 5 

Depth of articular ends 30. 

The better preserved of the caiidals without diapophyses, represented in 
Fig. 8, measures as follows : 

Lines. 

Length of centrum beneath 24 

Breadth of articular eud.s 38 

Depth of articular ends 3G 

The researches of Professor Marsh have proved the mosasauroid reptiles 
to have had four limbs constructed as paddles and adapted to swimming. 
Previous to his discoveries it was supposed that posterior limbs were absent. 

Specimens of limb-bones, found in association with the vertebral specimens 
above described, are supposed to belong to the posterior limbs, from the latter 
pertaining to the back part of the column. 

The femur represented in Fig. 9, Plate XXXV, is a broad bone strikingly 
diiFerent from the humerus of Clidastes. The specimen is probably more^ 
flat than in the normal condition, as its many fractures are evidences of its 
having been crushed. 

The distal extremity is much the wider, and the upper extremity is but 
little wider than the shaft. The head appears as a wide, lenticular, convex, 
and very rugged surface. The lower extremity ends in a long, narrow, ellip- 
tical, rusared surface for articulation with the bones of the fore-arm. From 
the posterior part of the shaft there projects a thick, convex ridge, which 
terminates above in an oval, flat, rugged surface, sloping from that of the 
head of the bone. 

The rugged, articular surfaces of the femur would appear to indicate a 
cartilaginous continuity with the contiguous bones more intimate than in 
Clidastes. 

The measurements of the specimen are as follows : 

Liues. 

Length of femur ^" 

Breadth of head ^^i 

Breadth of distal extremity ^^ 

Breadth at narrowest part of shaft ^^ 

Thickness of head and trochanter 28 

Greatest thickness of lower extremity '■ ^'^ 

The remaining two bones I take to be those of the leg, though I am 
uncertain in regard to their relative position with cacli otlier mid llic icmm: 
35 G 



274 



ni 



The specimen represented in Fig. 10 I suppose lu be a filnila, though it may 
he an uhia. It is a broad bone, almost as wide as the femur, but not so long. 
Its flatness has been somewhat increased by pressure. The upper extremity 
presents a wide, lenticular, uneven, convex, and roughened surface for carti- 
laginous union witli the femur. The lower extremity presents a similar sur- 
face, Init wider and of less depth or thickness. 

The measurements of the specimen are as follows: 

Liues. 

Length of fibula ". 66 

Width of upper extremity 54: 

Thickuess of upper extremity 21 

Width of lower extremity, partly estimated 65 

Thickuess of lower extremity 17 

Width of shaft near middle 38 

Thickness of shaft 13 

The supposed tibia, represented in Fig. 11, is a mucii smaller bone than 
the fibula. It is clavate, witli the lower extremity the more expanded and 
thinner. The upper part of the shaft is compressed cylindroid, and becomes 
wider and more compressed below. The upper extremity presents a trian- 
gularly oval, slightly convex, articular surface, rugged as in the other bones. 
The lower articular surface is transversely convex and widely lenticular. 

The measurements of the specimen are as follows : 

Lines. 

Length of the tibia 45 

Width of upper extremity 21 

Thickness of upper extremity 14 

Width of lower extremity 34 

Thickness of lower extremity 11 

Width of narrowest part of shaft 12 

Thickness of narrowest part of shaft 10 

Tylosaurus prorigee. 

Dr. Sternberg's collection of Kansas Cretaceous fossils, ])reserved in tiie 
Museum of the Smithsonian Institution, contains specimens pertaining to 
several individuals of a large Mosasaurus-like reptile, approximating in size 
the Maestricht Monitor of Europe, and tlie Mosasaurus MitcheUi of New 
Jersey. The specimens appear to pertain to the same animal as that de- 
scribed by Professor C-ope under the names of Macrosai/rus and Liodon pro- 
riger, and afterward, as in the case of the former species, referred to another 
genus by Professor Marsh, under the name of Rhinosaurus, then by Professor 



275 

Cope to Rliampliosauniy, and finally by Professor Harsh in Tylosaurus. A 
series of specimens belonging to one individnal, from the yellow chalk ol 
Kansas, consists of several' small fragments of jaws with bases of toetii, a 
basi'OCcipital bone, and five vertebrsa. 

The basiroccipital is obliquely distorted, from pressure. It has attached 
the diverging processes of the basi-sphenoid. The condyle has approximated 
3 inches in transverse diameter, and is about 2 inches in depth. The diverg- 
ing processes of the basi-sphenoid, at their conjunction with the basi-occipital, 
are about 3f inches wide. The vertebras are all more or less crushed ar/d 
distorted. One of the specimens, a posterior cervical, has the body below 3 
inches in length, and the truncated hypapophysis about 1^ inches in diam- 
eter. The articular ball and socket approximate 2^ inches in diameter. 

In three of the vertebral specimens, of about the same length as the pre- 
ceding, the hypapophysis is rudimental. The remaining specimen is a more 
posterior dorsal, and is of nearly the same size as the other vertebras. 

A second series of specimens, belonging to another individual, consists of 
several much-mutilated cervical centra, small fragments of jaws with bases 
of teeth, a coronoid bone, a fragment of a quadrate bone, and the end of the 
premaxillary. 

The latter specimen, represented in Fig. 12, Plate XXXV, exhibits tlie 
peculiar character of the extremity of the muzzle in Mosasaurus and its allies. 
It forms a solid, conical, osseous prominence, with the end obtusely rounded 
and projecting beyond the anterior teeth. The sides of the premaxillary 
toward the end are perforated with large" vasculo-neural foramina. The pro- 
jecting end of the bone extends about IJ inches in advance of the bases of 
the first pair of teeth. Immediately in front of the latter there is a small 
conical process. 

Several specimens of a third individual consist of a caudal verteljra and 
two teeth, which, from the adherent matrix, have been obtained from white 
or creatn-colored chalk. 

The vertebra is comparatively well preserved, not being crushed nor hav- 
ing its body distorted, as is so frequently the case in the specimens which 
have come under my observation. It is from the caudal series wifhout 
diapophyses or transverse processes, and is represented in Figs. 1, 2, Plate 
XXXVI. The posterior ball, defined from the body by a narrow ledge, and 
the anterior cup are nearly circular, with a slight hexahedral disposition 



276 

The neural arch exliibits rudiments of zygapophyses. The bottom of the 
body is provided with a pair of deep, conical pits for the attachment of a 
chevron-bone. The pits are defined with a prominent margin most project- 
ing anteriorly. 

The measurements of the specimen are as follows : 

Lines. 

Leugth of the body inferiorly 20 

Diameter of the body at the extremities 30 

Of the two specimens of teeth, one is crushed nearly flat; the other, well 
preserved, is represented in Fig. 3. It presents the usual form more or less 
characteristic of Mosasaurus. It is curved conical, with the inner and outer 
surfaces defined by acute ridges. The surfaces ai-e subdivided by longitudinal 
ridges, becoming obsolete toward the point of the tooth. The intervals of 
the ridges are feebly concave and faintly rugose. Internally near the base 
they are delicately striate. 

The length of the crown externally is 20 lines ; the diameter at base is 10 
lines. 

Several additional specimens, apparently belonging to another individual, 
consist of small fragments of jaws and palatine bones with bases of teetli. 
Among the" specimens is a portion of a splenial bone, with" its posterior artic- 
ular surface nearly entire, as represented in Fig. 13, Plate XXXV. The 
articular surface is a pyriform excavation, with a ridge descending from the 
upper part internally to near its center. 

LESTOSAURUS. 
Lestosaurus coryph^us. 

Dr. Sternberg's collection of fossils from the Smoky Hill River, of Kansas, 
belonging to the Smithsonian Institution, contains numerous specimens of 
dorsal vertebrae of a mosasauroid, which have the appearance as if they had 
pertained to a single individual. There are about fifty of these vertebras, 
but all have been more or less compressed from pressure of the superincum- 
bent beds to that in which they lay, so that not a single specimen preserves 
the exact original lorni. They ditfer but little in size, the more anterior 
being somewhat shorter than the others. 

The specimens appear to belong to the animal described by Professor 
Cope under the name of Holcodus corypliceus, which Professor Marsh has 
referred to another orcnus with the name of Lestosaurus. 



277 

• 

Fig. 5, Plate XXXVI, represents one of the best preserved of the speci- 
mens from the back of the series. In its present condition the centrum 
beneath is 27 Unes long, and the ball and socket ends are about 16 lines in 
depth and 2 inches in width. The neural atch between the ends of the fore 
and aft zygapophyses measures 34 lines. 

Another similar specimen, represented in Fig. 4, exhibits distinct rudiineuts 
of a zygosphenal articulation. The length of its centrum beneatli is 33 lines. 

The shortest of the series of the dorsals measures beneatli about 2 inches 
in length ; the longest from the back of tlie series measures about 3f inches 
in length. 

The same collection contains six specimens of cervical vertebrae, which 
may perhaps belong to the same species, if not the same individual, as the 
dorsals above noticed. The specimens are all distorted from pressure. One 
of them is an axis without the odontoid process and the suturally connected 
pieces of the atlas. The articular ball of the centrum is transversely hexa- 
gonally oval, 1.2 inches wide, and scarcely 1 inch deep. 

Another cervical centrum, in some degree compressed from above down- 
ward, is represented in Fig. 6, Plate XXXVI. It measures 1.9 inches in 
length below and is 3 inches wide between the ends of the transverse 
processes. 

Another specimen, represented in Fig. 7, probably a second cervical, is 
nearly complete, but considerably distorted. Its measurements are as 
follows : * • 

luelies. 

Length of centrum inferiorly 2. 00 

Length between fore and back zygapophyses 2. 80 

Height from hypapophysis to end of spinous process 3. 20 

De])th of posterior ball of centrum 1. 55 

Width of posterior ball of centrum 1. 05 

Dr. Sternberg's collection further contains a number of specimens of 
caudal vertebra, probably belonging to the same species as the former, anil 
apparently pertaining to two different individuals. There are twenty-six 
.specimens, all provided wdth diapophyses or transverse processes, and with 
hypapophyses for chevron articulation. 

Figs. 8, 9, 10, Plate XXXVI, represent the first and last of a consecutive 
series of four anterior caudals. The body of these has tiie length nearly as 
great as the breadth and about equal to the depth. The neural arches are 
without zygapophyses, or exhibit mere rudiments of tiiein. Tin- articular 



278. 

• 

ball anil socket are wider tiiau high, and arc widest below the middle. The 
outline of the articular surfaces is emarginatc and sloping at the sides above, 
and seniicircular below. The neural canal is triangular. The transverse pro- 
cesses project obliquely from th"fe lower part of the body, and they become 
successively narrower. The hypapophyses are excavated into deep conical 
pits, directed obliquely backward, for movable ai-ticulation with chevrons. 
The pits are small in the first of the series of specimens and become succes- 
sively larger. 

Measurements of the two vertebrae represented are as follows : 



Inches. 1 Inches. 



Li^iigth of ceutrum, including edge of ball 

Width of ball 

Depth of ball 



1. G5 1. 45 

1.75 I 1.65 
1. 50 1 1. 45 



In a consecutive series of four posterior caudals with small diapophyses, 
the bodies have nearly the same form as in the preceding, but the articular 
extremities are of more uniform diameter and of a more hexahedral outline. 
The transverse processes are small and project just below the center of the 
sides. The chevron-pits are well developed, and resemble those of the pre- 
ceding caudal specimens. Two of the caudals are represented in Figs. 11, 12, 
Plate XXXVI. 

The four caodals together measure f).3 inches in length. The diameters 
of the cup of the first of the series is 1.4 inches ; the diameters of the ball 
of the last of the series is 1.3 inches. 

A mutilated posterior caudal centrum, apparently of the same animal as 
the preceding, is without diajjophyses, but has well-produced chevron-pits. 
The length of the centrum is less than the depth, and this is greater than the 
width. The articular ends are hexahedral in outline. The ceutrum 
measures 9 inch in length; 1.2 inches wide, and 1.3 inches deep. 

The same collection contains the greater part of a palate-bone, with teeth, 
represented in Fig. 12, Plate XXXIV, which may perhaps belong to the 
same species as the specimens above described. The specimen contains the 
remains of seven teeth, which probably is within two or three of the 
complete series. The teeth are compressed conical, strongly curved back- 
ward or hooked, obtuse in Cront, acute-edged behind, are perfectly smooth, 
and present no facets or sul)divisioual planes of the surface. 



279 

Two limb-bones, represented in Figs 13, 14, Plate XXXVI, pertaining 
to the same collection, are supposed also to belong to the same animal as the 
above. I feel unable to determine their character. The broader one I sup- 
pose to be an ulna or a fibnla. It resembles in its shape and construction 
the corresponding bone of the New Mexico mosasauroid, represented in Fig. 
10, Plate XXXy, but is much smaller. 

Its measurements are as follows: 

Indies. Lines. 

Leugth at the upper extremity - 4 3 

Breadth of upper extremity 2 9 

Thickness of upper extremity 10 

Breadth of lower extremity 3 4 

Thickness of lower extremity 7 

Width of shaft at middle 2 

Thickness of shaft at middle 11 

The smaller bone of Fig. 14 is probably a radius or a til)ia. 
Its measurements are as follows : 

■Inches. Lines. 

Length 3 7 

Breadth of upper extremity •. ■ - 1 4.} 

Thickness of upper extremity 9 

Breadth of lower extremity * 1 10 

Thickness of lower extremity 9 

Width of shaft at middle . 9 

Thickness of shaft at middle 7 

MOSASAURUS (?) 

The cabinet of Swarthmore College, in the vicinity of Philadelphia, con- 
tains a number of fossils from the Cretaceous formation of Nebraska, pre- 
sented by Mr. George S. Truman. They were collected by him from the 
hills on the Missouri River, near the Santee Agency, in L'Eau qui Court 
County. They consist of bones and teeth of fishes and reptiles, among 
v^^hich are a number pertaining to the Polycotylus latiinnnls of Professor 
Cope, originally described from remains found in Kansas. 

An anterior caudal vertebra of a Mosasaurus, in Mr. Truman's collection, 
is represented in Fig. 15, Plate XXXVI. The vertebra has the Ibrm usually 
assigned to the genus. It retains the neural arch, but has lost its spine. 
From the lower part of the body project the roots of strong transverse pro- 
cesses. Beneath the body there is a strong pair of eminences projecting just 



280 

back of the middle and terminating in nearly flat articular fliccts fur a chevron. 
The surface between these eminences forms a moderately deep concavity. 
The measurements of the specimen are as follows: 

Lines. 

Lengtli of the body beneath 31 

Depth anteriorly 35 

Breadth anteriorly 42 

Mr. Truman's collection contains several t;eeth which may probably belong 
to the same animal as tlie vertebra just described. 

The largest of the teeth is represented in Fig. 18, Plate XXXIV. It pre- 
sents the usual mosasauroid form, being curved conical, with the inner and 
outer surfaces unequal in extent and degree of convexity and separated by 
acute ridges becoming more prominent near the apex of the crown. The 
enamel is longitudinally striate, especially toward the base of the crown, 
where more marked ridges show a tendency to divide the surfaces into narrow 
planes. 

The specimen is a shed tooth, and measures a little more than 2 inches in 
length ; and the diameter at base is about 14 lines. 

A second tooth, represented in Fig. 21, has nearly the same characters 
as the former. It is smalle*, more compressed, so that its section is 
more elliptical, and its inner and outer surfaces are more equal. It is also 
a shed specimen, and measures IJ inches in length. Its base, an outline of 
which is seen in Fig. 22, measures 10 lines fore and aft, and 8 lines trans- 
versely. 

The third specimen, represented in Fig. 19, has nearly the same form as 
the preceding, but has its surfaces distinctly subdivided into narrow, slightly 
depressed, smooth planes, of which there are six externally and seven intei-- 
nally. Transverse outlines of the base and of the crown a short distance 
above are given in Fig. 20. The length of the tooth, also, like the other, a 
shed sjiecimen, has been about 20 lines. The diameter of the base fore and 
aft is lOf lines; transversely 8|- lines. 

Fig. 16 represents a small tooth, accompanying the former specimens, 
which I suppose to be from the back pari of the series of the same spe- 
cies as the teeth of Figs. 18 and 21. It is more curved in proportion 
with its length than in these, but has nearly the same outline in trans- 
verse section, and has the enamel striated in the same manner. Its length 
when complete has been about an inch. Its diameter at base fore and aft 
is 64 lines; transversely .6 lines. 



281 

CLIDASTES. 

The extinct reptiliiin genus' CUdastes, characterized by Professor Cope, 
is especially distinguished from Mosasaurus and its nearer allies by the 
possession of an additional mode of articulation to the ordinary one in 
the vertebrae, such as is found in the living iguanas. The vertebrae are 
otherwise nearly like those of Mosasaurus. The general form and construc- 
tion of the skull and the character of the dentition are the same in both 
genera. 

Half a dozen species of CUdastes have been indicated by Professors Cope 
and Marsh, from remains found in the Cretaceous formations of New Jersey, 
Alabama, and Kansas. 

Clidastes intekmedius. 

A species different from those described by the authors just named is 
indicated by a small collection of remains, presented to the writer by Dr. J. 
C. Nott, formerly of Mobile. The specimens, consisting of several jaw-frag- 
ments and vertebrae, were taken from an excavation 40 feet beneath tlie 
surface, imbedded in the rotten limestone, . of Cretaceous age, in Pickens 
County, Alabama. 

The remains indicate a species of more robust proportions than Clidastes 
propi/tlwn, described by Professor Cope, from the great part of a skeleton 
discovered in the same formation near Uniontown, Alabama. It was a third 
less in size than the typical species C. iguanavus, described by the same 
author, from an isolated dorsal vertebra obtained from the Cretaceous green 
sand of New Jersey. 

Fig. 1, Plate XXXIV, represents the anterior extremity of a dentary bone, 
probably more than one-half of the whole. It would appear to have been 
proportionately of greater depth and thickness in relation with its length thim 
in C. propython. It is also of more uniform depth at its fore part and less 
pointed at the end. 

The fragment contains the remains of a series of nine teeth, occupying a 
space of 5^ inches. The teeth surmount robust osseous pedestals, of which 
about Iwo-thirds of the length are included within about an equal extent of 
the depth of the jaw. 

The crown of a second tooth, (Fig. 5,) inclosed within a cavity of the 
pedestal of its predecessor, is 5 lines in Icngtli and about 2i- lines in l)rca(lth 
36 G 



282 

at base. It is curved conical, feebly compressed from without inwardly, and 
has its inner and outer surfaces well defined b.y acute borders. The exposed 
inner surface of the crown exhibits no divisional planes, and lias its enamel 
minutely wrinkled. 

The crown of a tooth (Fig. 4) occupying a corresponding cavity of the 
ninth pedestal, probably not fully produced in its length, in its present condi- 
tion has a breadth exceeding the latter. The crown is a broad cone about 
the length of the tooth first described, ])ut with double the width at base. 
The exposed inner surface is defined in the usual manner from the outer, and 
exhibits no divisional planes. The enamel is minutely wrinkled. 

The depth of the jaw-fragment below the visible base externally of the 
first dental pedestal is. three-fourths of an inch ; the depth below the seventh 
pedestal is 14^ lines. 

The s[)lenial bone -advanced as far as the back part of the sixth tooth. 
Beyond it the Meckelian groove is deep and wide compared with that in C. 
yropython, and extends to near the end of the jaw. 

Fig. 2 represents a posterior fragment of the opposite dentary bone, con- 
taining the remains of a series of six teeth. The mutilated crowns of the 
anterior two teeth retained in the specimen exhibit a swollen base, which 
may also be seen to be the case in the crowns of the sixth and seventh teeth 
of the anterior dentary fragment. 

From the two fragments of opposite dentary bones I am unable to ascer- 
tain the number of teeth which belonged to the complete series, but it seems 
to me that the seventh tooth of the anterior fragment about corresponds with 
the first retained tooth of the posterior fragment, which would indicate a 
series of twelve teeth. 

Fig. 10 represents an axis from the same individual as the preceding speci- 
mens. It has the same form as that of C. i^yopijihon. The odontoid process, 
and the elements of the atlas, all of which articulate suturally with the axis, 
are detached from the specimen and do not accompany it. 

I'lie measurements of the axis are as follows : 

Lines. 

Length of body tbrough center, devoid of odoutoid process 18 

Breadth of axis between posterior ends of diapophyses , 28 

Widtli of posterior ball -. lOJ 

Height of posterior ball r ■ - • - r - 10 

Width of hypopopliysis 8 

Two mutilated dorsal vertebrae exhibit the zygosphenes and zygantra as 



283- 

well developed ])roporlionately as in Clidastes propi/tlion. Measurenieiils of 
the better preserved of the specimens arc as follows : 

Liues. 

Leugtli of the boil.v iiiferiorly : IS 

Width of the ball and socket 12 

Height of the ball and socket 10 

Clidastes affinis. 

Some remains submitted to my examination by the Smithsonian Institution 
-may perhaps indicate a species of .Clidastes distinct from the former. The 
specimens were discovered by Dr. George M. Sternberg, "United States Army, 
in the Cretaceous formation on the Smoky-Hill River, Kansas. 

Fig. 6, Plate XXXIV, represents a nearly complete dentary bone, which 
is accompanied by that of the opposite side. It contains the remains of a 
series of twelve teeth, while there is one less in the other bone. 

The anterior extremity of the jaw is of rather less depth and slightly 
greater thickness than in the corresponding part of Clidastes intermcdius. 
The splenial bone appears to have I'eached as far forward as the position of 
the fourth tooth. 

The anterior teeth appear to have been larger, and the intermediate ones 
smaller, than in C. intermedius, though this may have been a variable char- 
acter in the same species. Portions of the bases of the crowns of several of 
the back teeth exhibit the enamel strongly striated, and the surfaces of the 
teeth also present evidences of subdivision into narrow planes. 
. A fragment from the back part of a maxillary from the same individual 
contains the bases of four teeth. The last of the series retains part of the 
crown, which is strongly- striated internally, and distinctly subdivided, into 
narrow planes externally. In the remains of the teeth of the specimens 
referred to C. intermedius there is no trace of subdivisional planes to the 
crowns, but this may have been a variable character in the species. 

Fig. 7 represents the back part of the right ramus of the mandible of the 
same individual, seen on its inner side. It exhibits the same construction as 
the corresponding part in C. propython. The articulation is nearly equally 
divided between the angular and articular bones. 

Measurements of the jaw-specimens are as follows : 

Lines. 

Length of dentary bone 12G 

Length of serie.s of twelve teeth Ill 

Depth of jaw below first tooth 10 



•284 

Lines. 

Depth of jaw below fourth tooth 11 

Depth of jaw at the outer side of the glenoid articulation 24 

Length of projection back of the glenoid articulation 20 

Transverse diameter of glenoid articulation 18 

Vertical diameter of glenoid articulation 16 

An axis and a dorsal vertebra accompanying the former specimens probably 
pertained to the same individual. They are both considerably distorted from 
pressure at the sides. 

The axiS'is rather longer than that of C. interniedius, while its liypopophysis 
is considerably smaller at the extremity, and the ball of the centrum is more 
uniform in diameter, or is less emarginate above. The lower element of the 
atlas remains in firm sutural connection with the body of the axis, but the 
odontoid element of the latter and the lateral elements of the atlas are absent. 

The dorsal specimen retains the neural arch with its characteristic zygail- 
tral articulation. 

Measurements of the vertebrae are as follows : 



Length of axis through center of the body 



Lines. 
>>>> 



Width of ball of body of axis 10^ 

Height of ball of body of axis 104- 

Length of body of dorsal vertebra iuferiorly 22 

Accompanying the former specimens there are several othei's which, if 
they did not pertain to the same individual, probably belonged to the same 

species. 

Two fragments of the upper part of the cranium represented in Fig. 8 
resemble the corresponding portions in Clidastes propijtlion^ as described and 
figured by Professor Cope, and differ only in the greater size. Fig. 9 repre- 
sents an isolated basi-sphenoid bone, probal)ly from the same skull. 

These skull-fragments indicate an animal about one-third larger than C. 
propython^ as described by Professor Cope. 

It is a question of some importance how far. difference in size among the 
mosasauroids may be a test of difference in species. Among the numerous 
remains of these animals which have been discovered I have never yet 
observed any which presented any evidence relating to age. In no case 
have I seen a vertebra in which the neural arch was not continuous with the 
centrum, so that I have been led to suspect that the former grew out of the 
latter, as in most fishes, and was never united with it by articulation, as in 
the crocodiles, &c. In this view of the case, some of the many described 



285 

species of mosasauruids may have been foundccl on differeiit ages of the 
same. 

Fig. 11 represents a humerus accompanying the former specimens, and 
probably belonging to the same species, if not the same individual. In its 
form and construction it closely resembles the corresponding bone of C. 2^>'o- 
python. 

The specimen is somewhat crushed, which perhaps to some extent makes 
it appear proportionately flatter than the humerus of C. propython, described 
and figured by Professor Cope. 

The length of the bone does not exceed the breadth of its distal extremity, 
which is the wider one. 

The measurements of the specimen are as follows : 

Lines. 

Length of humerus at middle 35 

Breadth of iiroximal extremity 28 

Breadth of distal extremity 35 

Breadth at constricted middle of shaft 20 

Thickness of head 8i 

Thickness of distal end 9^ 

Order Lacertilia. (J) 

TYLOSTEUS. 

Tylosteus oenatus. 

The above name has been proposed for a supposed genus of lacertian 
reptiles, founded on a singular fossil represented in Fig. 14, Plate XIX. 
The specimen was obtained by Professor Hayden in the "Black Foot" 
country, at the head of the Missouri River, and was probably derived from 
the Cretaceous formation. It looks as if it might be an element of the 
osseous dermal armor of some animal, whether reptile or mammal is by no 
means certain, though, as before intimated, I suspect the former. 

The specimen is imperfect or broken at the borders. Its inner surface is 
concave !• the outer convex, and ornamented with large mammillary bosses. 
The latter are about fifteen in number and of different sizes. They are 
porous and of a less dense character than their shield-like basis. The 
diameter of the fossil is about 2 inches ; its thickness an inch. 

Accompanying the specimen just described there is an isolated phalanx, 
represented in Fig. 13. Though suspected to pertain to the same animal, 
the reference is uncertain. It is a ierminul phalanx nearly 2 inches long. 



286 

and with the expanded extremity nearly circular at the border and 16 lines 
wide. The upper part of the bone presents a nearly straight slope in its 
length, and is convex transversely. The under part is likewise straight along 
the middle, transversely convex posteriorly, and nearly flat at the expanded 
end. The lower surface of the latter presents near the middle a pair of 
vascular foramina, and several similar foramina are found near the border. 
The articular end is transversely -elliptical and barely depressed. Its trans- 
verse diameter is 15 lines; its vertical diameter 10^ lines. 

Order Sauro])te7-ijgia. 
OLIGOSIMUS. 

OlIGOSIMUS GRANDiEVUS. 

A fossil ol)tained on Henry's Fork of Grreen River, Wyoming, during 
Professor Hayden's exploration of 1870, would appear to indicate an extinct 
reptile allied to Plesiosaurus and Discosaurus. In general aspect, the 
specimen is different from those in company with it, and I think it doubtful 
whether it was an associate of the other fossils, which belong to the Bridger 
Tertiary formation. It was found as a detached specimen, and has no 
adherent matrix. It probably is of Cretaceous age. 

The fossil, represented of natural size in Figs. 18, 19, Plate XVI, consists 
of the body of a caudal vertebra, apparently from the root of the tail. It 
was evidently from a mature animal, as the neural arch was firmly co-ossified, 
leaving no trace of the original separation. 

In shape and construction the body resembles the corresponding portion 
of the vertebrae in Plesiosaurus and Discosaurus, but the proportion of length 
to the other dimensions is much less, and the depth also is not so great. 

The body is biconcave, the concavities being of moderate and nearly equal 
depth. Deepest at the central half of the area, the peripheral half of the 
articular surfaces becomes more aljruptly shallower, and with the deflexed 
edges somewhat convex. Near the border, the articular surfaces are defined 
by -a narrow circular groove. 

The posterior articular surface of the body at the sides below is deflected 
in a pair of widely separated facets for a chevron-l>one. The facets are 
sustained on processes extending forward more than a third of tlie length of 
the body. Similar facets and processes are absent on the front of the bone. 



2&7 

Tlie sides of" ilie IxkIv are coinparativcly fcel)ly coiistriclcd, much leys lliau 
in Plesiosaurus, and beneath, the constriction is triHing in degree. 

Transverse processes or diapophyses project from the sides of tlie l)ody, 
just above its middle and below tlic conjunction of the neural arch. Their 
bases ate broadly conical; wider than high, and appear originally to have had 
a sutural connection. The ends are broken off in the specimen. 

The nsual nutritive foramina are visible at the floor of the verteljral canal 
and beneath the body. 

The peculiarities of the fossil appear to justify its reference to a previously 
undescribed genus and species, and we have therefore attributed it to an 
animal with the name at the head of this chapter. 

The measurements of the specimen are as follows: 

Lines. 

Lengtli of body beneatb 12 

Depth of body in front 19 

Width of body iu front 23 

Widtli of body at chevron-facets . 18 

Width of vertebral canal 6 

Leugtb of axis of tlie body 8 

NOTHOSxiURUS. 

NOTHOSAURUS OCCIDUUS. 

The above name was appropriated to a saurian indicated by a detached 
vertebral body or centrum, represented in Figs. 11 to 13, Plate XV. The 
specimen was obtained by Professor Hayden on the Moreau River, a tribu-. 
tary of the Upper Missouri, and is probably a Cretaceous fossil. In form and 
construction it resembles the vertebral centra of Nothosaurus, an extinct 
reptile of the Triassic formation of Europe, and probably it belongs to an 
animal of the same order if not the same genus. The specimen appears to 
pertain to a dorsal vertebra, to which the neural arcli was attached by broad 
suture, as usual in the sauropterygians. 

The body is nearly cylindric, longer than wide or liigh, and is moderately 
narrowed a short distance from the ends. Inferiorly it jirescnts a central 
roughness, probably for ligamentous attachment. The articular ends are 
nearly round, but flattened above, and are neai'ly as wide as high. They are 
slightly concave and exhibit a slight central protuberance, apparently the 
ossified notochord. 

The sutures for the neural arch extend nearly three-fourths the length 



288 

of the centrum from its posterior end, and they reach downward to the 
middle of the sides. The bottom of the spinal canal is narrowest at the 
middle, grooved on each side, and widens toward the ends of the centrum. 

The measurements of the specimen are as follows : Length of centrum, 
1 inch; depth in front, 10^- lines; width, 10 hnes. 

FISHE8. 

TELEOSTEI. 

Order Acantlwpteri. 

Sphyr^nid^. 

CLADOCYCLUS. 
Cladocyclus occidentalis. 

The genus of fishes above named was proposed by Agassiz on some remains 
consisting of large scales and portions of a vertebral column found in the chalk 
of Lewes, England. The name was applied on account of the branching of 
the tube in the scales of the lateral line ; and the fish was referred to the 
sphyreenoids. (Poissons Fossiles, V, 103 ; Atlas V, Tab. 25 a, Figs. 5, 6.) 

Some large scales, found by Dr. John E. Evans, and subsequently by Pro- 
fessor Hayden and Mr. Meek, in ash-colored shales of the Cretaceous series 
of Nebraska, I have supposed to belong to the same or a nearly allied genus. 
The scales vary in form and size, and may probably belong to several species. 
Mostly they are oval, with the length but little more than half the depth, 
while others are circular, and these may really pertain to a different species, 
if not genus, from the former. 

A broad oval scale, somewhat distorted and broken at the edges, is repre- 
sented in Fig. 5, Plate XXX. The inner portion exhibits numerous radi- 
ating ridges, while the outer portion, separated from the former by a narrow 
smooth tract, presents a minutely tubercular or granular aspect. The depth 
of this scale is estimated to have been nearly 2^ inches, and its length nearly 
1^ inches. 

Another similar but less perfect specimen appears to have measured about 
If inches wide by \\ inches long. 

A third specimen^ represented in Fig. 21, Plate XVII, has measured rather 
more than 1 inch wide and f inch in length. 

Another scale, represented in Fig. 22, has (he same structure as the pre- 



289 

ceding, but is circular in tbrai. Its difimeter is about 14 lines. This prob- 
ably belongs to a ilillerent species, and perhaps genus, from the ibrnier. 

x\nother specimen is a nearly smooth oval scale, which has been about 13 
lines wide and 9 lines long. It exhibits obscure radiant lines on the inner 
portion, but no granulations are evident on the outer portion. This may 
belong to another fish than that of the preceding specimens. 

ENCHODUS. 

Enciiodus Shumakdi. 

The extinct genus above named was inferred by Agassiz from some remains, 
consisting of jaws and teeth, found in the chalk of Europe, and was by him 
attributed to the sphyreenoid family. Several species have been since de- 
scribed from similar remains found in the deposits of Cretaceous age in the 
United States. . One of these, under the above specific name, was indicated 
Iiy a dentary bone with teeth, found by Dr. Benjamin F. Shumard in the same 
formation in which were discovered the large scales referred to Cladocyclus. 

The specimen is rudely represented in a reversed position in Fig. 20, Plate 
XVII. The dentary margin of the bone is 11 lines long, and contains six long 
narrow teeth, and in the back intervals a number of minute ones. 

The first of the larger teeth is the longest, and is situated a short distance 
from the end of the bone. Including its thickened base it is 2 lines long by 
about one-fifth of a line wide. It is a long, narrow, straight cone, laterally com- 
pressed, trenchant at the borders, and ends in a point with a slight posterior 
projection or half barb. The posterior five larger teeth are situated at irreg- 
ular distances apart, and measure from one to one and one-fiflli lines in 
length by about one-sixth of a line in breadth at base. They are nearly like 
the largest tooth, but are slightly more curved, and have no projection to the 
back of the point. The minute teeth in the back intervals of the larger ones 
and back of these arc not over the one-fifth of a line long. 

PHASGANODUS. 

PlIASGANOEUS DIRUS. 

An extinct genus of fishes sujiposed to belong to the sphyrajnoid family, 
and nearly related with Enchodus, has been described under the above name. 
It was inferred from a specimen of a mutilated dentary bone with teeth, 
37 G 



290 

imbedded in a piece of brown sandstone, obtained by Professor Hayden from 
a Cretaceous deposit he has indicated as No. 5, on Cannon Ball River. 

The specimen with the remains of five large teeth, reduced one-third, is 
represented in Fig. 24, Plate XVII. The third tooth of the series, preserved 
entire and separated from the former, is represented in Fig. 23. 

The dentary bone exhibits nothing peculiar in the present condition of the 
fossil, and appears not to liave differed in any important point from that of 
Enchodus. 

The teeth differ from those of the latter. They are proportionately shorter, 
saber-like, and situated on broad bases, with an oblique direction to the edge 
of the jaw. The thick back border is directed inwardly ; the trenchant 
border forward and outward. The point is cut off in a slanting manner pos- 
teriorly. The back part of the crown toward tiie base and extending on the 
sides is fluted, but toward the point and trenchant border is smooth. In sec- 
tion the crown is ovate, with the long diameter 2| lines. The length of the 
tooth, including its thickened base, is 10 lines; without the base, the crown 
measures 7 lines. 

Order Malacoyteri. 
SlLURID^E. (I) 

XIPHACTINUS. 

XiPHACTINUS AUDAX. 

Under the above name, I described an ichthyodorulite belonging to the 
collection of the Smithsonian Institution. The specimen was obtained from 
the Cretacous formation of Kansas, by Dr. George M. Sternberg, United States 
Army. I supposed it to l)e the pectoral spine of a large siluroid fish, but 
according to Professor Cope, who has had the opportunity of examining many 
remains of fishes from the Cretaceous formation of Kansas, it belongs to a 
fish of a peculiar family. This he names Saurodontidee, represented by Sau- 
rocephalus and some other genera. At first the spine was referred to the 
last-named genus, but latterly he appears to be in doubt whether it belongs 
to this or some other nearly allied genus. The specimen is represented in 
Figs. 9, 10, Plate XVII, one-third the diameter of nature. 

The spine is unsymmetrical, thus rendering it probable that it belonged to 
one of the lateral pairs of fins rather than to any of the vertical fins. It is 
a broad saber-shaped wenpon, in its present condition about 16 inches in 



291 

length, which is nearly its entire extent, judging from the tliinning and round- 
ing of the broken end. Its breadth the greater part of the length is nearly 
uniform, and at tlic middle is nearly 2 inches. Toward the distal end it 
becomes slightly less wide and thinner; toward the proximal end it undei'goes 
a greater reduction in width, and becomes much thicker. 

The upper surface of the spine, represented in Fig. 10, for the most [)arl 
is nearly Hat except toward the rounded borders. It is invested with a 
tliiu layer of ossific substance of a nnn-e dense character than the compact 
bone beneath. The surface is striated or ornamented with raised lines, which 
are longitudinal and parallel, but on portions of the surftice are somewhat 
irregular. Some of the lines branch, and the slightly divergent branches 
include other commencing lines. At the distal end of the spine, near the 
anterior border, the lines break up into finer branches which curve outwardly 
to the edge. 

The under surface of the spine (Fig. 9) is uneven. A prominent ridge, 
commencing at its proximal extremity and occupying more than two-thirds 
its width, extends outwardly and gradually declines to a point near the center 
of the inferior surface. A shallow groove commences in front of the ridge, 
widens outwardly, and extends beyond the former upon the anterior half of 
the inferior surface of the spine. Back of the commencement of the ridge 
there is a concave hollow, which narrows outwardly into a deep groove, and 
this, pursuing the same course, widens and opens downward upon the posterior 
half of the inferior surface of the spine to its distal end. 

The posterior groove for nearly half its length proximally exhibits a row 
of irregular pits at the bottom. The upper boundary of the groove in advance 
of the pits is transversely striate, and beyond the position of the pits exter- 
nally the corresponding surface presents the striae curling outward to the 
back edge of the spine. The bottom of the groove, external to the position 
of the pits, continues as a shallow channel running along the middle of the 
spine inferiorly to its distal end. 

The anterior border of the spine is convex in the length, obtuse internally, 
and acute externally. The posterior border is concave longitudinally, obtuse 
internally, and less acute externally than the anterior border. 

The inner extremity of the spine appears bent upward into a hook-like 
eminence with a pyramidal base extending above the general level of the 
spine. The end of the hook-like process is broken off. Its inner surface 



292 

forms an ellipsoidal longitudinal convexity, with the lower half more 
prominent and appearing to be an articular eminence. The outer extremity 
of the spine is broken, but it appears to have been rounded transversely, 
though it may have been pointed. 

The measurements of the spine are as follows: 

Inches. 

Lengtli of the spiue iu its present couclitiou IG 

Lines. 

Breadth of the spiue beyond the articular hook 17 

Breadth at the iuuer third 21 

Breadth at tlie middle 23 

Breadth uear the distal eud 20 

Thickness of the spine beyond the articular hook 14 

Thickness at- the inner third 9J 

Thickness at the middle - 6 

Thickness near the distal end 3 

The transverse section of the spine near the middle forms an irregular 

ellipse, as represented in the accompanying 
figure. The left-hand side beneath represents 
the posterior groove opening downward. 

Since writing the above,* I have had the op- 
portunity of examining the proximal half of a similar spine, from L'Eau 
qui Court County, Nebraska. It was found in association with remains of 
Mosasaiirus, &c., by George S. Truman, and presented by him to Swarth- 
more College, Pennsylvania. 

aANOIDEI. 
PYCNODUS. 

This genus, typical of an extinct family of fishes, was originally indicated 
by Agassiz in the Poissons Fossiles. Many species have been described, 
mainly from teeth and fragments of jaws with teeth, which are comparatively 
large and stout, and were adapted to crushing hard food, such as mollusks 
with their shells, crustaceans, &c. The remains have been found in the Tri- 
assic, Jurassic, Cretaceous, and early Tertiary formations of Europe. 

Pycnodus faba. 

A specimen, represented in Fig. 16, Plate XIX, indicates a species to 
which the above name has been given. It was submitted to my examination 
by Dr. William Spillman, who obtained it from the Cretaceous formation near 
Columbus, Mississippi. ' . 




293 

The specimen consists of a fragment of the ramus of a U)\ver jaw con- 
taining a numl)er of teeth. Four principal teeth and part of the attachment 
of another are retaineil in the fragment. These teetli are ranged oblicpiely 
parallel with one another from within backward and outward. In outline 
they are elongated-bean shaped, being slightly concave in front and convex 
behind, and slightly wider externally than internally. The first of the series 
is 7i lines wide by 2| lines fore and aft, and they successively increase in 
breadth to the last, which measures 8| lines wide by 2j|- lines fore and aft. 

At the bottom of the slope, to the inner side of the large teeth, there is a 
row of three smaller teeth and the traces of attachment of a fourth one. 
The three teeth, like the others, successively increase in size from before 
backward. They are ovoid, and situated obliquely nearly opposite the inter- 
vals of the large teeth. The first of the series is 2J lines in diameter fore 
and aft and IJ lines transversely; the last one is 3 J fines by 2 fines. 

The jaw-bone internal to the teeth just described rises in a ri<lge toward 
the symphysis. The slope at the fore part of the ridge exhibits the attach- 
ments of two minute teeth, indicating a second row internal to the largest 
teeth. 

To the outer side of the latter the specimen retains evidences of two rows 
of smaUer teeth. Of these, the first row shows remains of seven teeth in 
the length of space occupied by the five principal teeth, and, like these, they 
successively increased in size. Only the fourth tooth of tln^ row is preserved, 
and this is transversely ovoid, with tlie long diameter 2 lines wide and the 
short diameter If lines. 

Fig. 15, of the same plate, represents a specimen apparently from the same 
species, belonging to tlie Museum of the Academy of Natural Sciences of 
Philadelphia. It was presented by Dr. J. H. Slack, who obtained it from the 
green sand marl of Crosswicks, Burlington County, New Jersey. It consists 
of a small jaw-fragment containing three broad teeth simihir to the largest 
ones above described. 

An isolated tooth from New Jersey, submitted to my inspection by 
Professor G. H. Cook, is noticed in the Proceedings of the Academy of 
Natural Sciences of Philadelphia for 1857, p. 1G8, under the name of 
Pycnodus rohustus. The specimen represented in Figs. 18, 19, Plate 
XXXVII, has the same shape as in the largest teeth of those referred to 
P. faba, but is mucli larger. Its long diameter is 14^ lines, and its short 
diameter nearly 4 lines. 



294 

A similar tooth, nearly the same size but slightly more sigmoid, is repre- 
sented in Fig. 96, page 244, of Professor Emmons's Report of the North 
Carolina Geological Survey, published in 1858. Tiie specimen is attributed 
to the Miocene Tertiary, and is referred to a species with the name of 
Pycnodus caroHnensis. 

HADRODUS. 
Hadrodus priscus. 

The genus above named is obscure in its relations, and was originally 
described in 1857, in the Proceedings of the Academy of Natural Sciences 
of Philadelj)hia. It was founded on a specimen consisting of a bone with 
two singular-looking teeth, discovered by Dr. William Spilhnan, in the Cre- 
taceous formation in the vicinity of Columbus, Mississippi. 

The specimen represented in Figs. 17 to 20, Plate XIX, I have supposed 
to be a jiremaxillary bone of an animal allied to the extinct genus Placodus, 
■formerly considered to be a pycnodont tish, but now determined to be a 
sanropterygian reptile, 

The bone is nnsymmetrical, and sujiports two strongly co-ossified teeth. 
Whether the specimen is complete in itself or whether it is part of a larger 
bone, I have not been able to ascertain. 

The bone is quadrate in outline; thicker and longer on one side, and 
oblique at the upper border. The anterior surface is convex and compara- 
tively smooth. On each side and extending posteriorly, the bone is deeply 
excavated into large reserve cavities for successional teeth. The back surface 
between the cavities inclines from each side, forming a median angular groove 
descending to the interval of the teeth. The bone is more porous and striated 
posteriorly than anteriorly. 

The teeth remind one of the premolars of some pachyderm, rather thau 
the teeth of a fish or reptile. They are not exactly alike, and are co-ossitied 
with the bone by a firm osseous base or root, striated in front. They are 
quadrate in outline, with the breadth and height nearly the same, and the 
thickness about half. The crown is convex in front and at \he sides, and is 
bilobed at the triturating border, which slopes off posteriorly. An acute 
ridge and the conical blunted summits of the lobes define the outer from the 
inner surface. Smooth enameloid substance invests the crown, extending" 
twice the depth on the outer surface that it does on the inner suritice. In 
transverse section the teeth are ovoid. 



295 
The measuremenfs of llic fossil are as follows: 

Lines. 

Depth of bone 18-20 

Breadth of the bone 17 

Length of the larger tooth 8 

Width of same 8 

Thickness of same 5^ 

Depth of enamel Cf 

Length of smaller tooth 7f 

Width of same 7J 

Thickness of same 4+ 

Depth of enamel 0;^ 

I have arranged Hadrodiis with the Pycnodonts, though, like Placodus, the 
discovery of additional material may prove it to be a sauropterygian reptile. 
Of Placodus, Professor Owen remarks that the "teeth are implanted by 
short simple bases in distinct hollow sockets," (Palaeontology, 218;) and IMeyer 
says, "In wircklichen Alveolen stecken eigentlichen nur die Schneidezixhne 
mit gut ausgebildeten Wurzeln, der Wurzeltheil der iibrigen Zahne ist mehr 
rait dem Knochen, dem die Zahne angehoren, verbunden.'' Hadrodus in 
the relation of the teeth would appear to be different, as they are firmly 
co-ossified by short bases with the border of the jaw. They exhibit no 
trace of implantation by sockets, though the successional teeth before being 
established in a fixed manner in functional position must appear at least to 
spring from sockets. 

BLASMOBRANCHII. 

Order Plagiostomi. 

PTYCHODUS. 

Ptychodus Mortoni. 

The extinct genus of cestraciont fishes above named was inferred by 
Agassiz, from isolated teeth, the only parts yet found which can l)c A\itii any 
certainty referred to the same animal. A number of species have been indi- 
cated, mostly by the same authority, from specimens ibund in the Cretaceous 
formations of Europe and America. 

Teeth of Ptychodus Mortoni have been discovered in the Cretaceous de- 
posits of Alabama, Mississippi, and Kansas, but I have seen none fi'rim the 
corresponding formation of New Jersey or elsewhere. 

The Smithsonian Institution has submitted to my examination a collection 



■296 



of fouiteeii specimens of toctli obtained by Dr. George M. Sternberg, United 
States Army, from the banks of Chalk Bluff Creek, a branch of Smoky Hill 
River, about sixty miles east of Fort Wallace, Kansas. The specimens were 
found in two parcels, each together, as if pertaiuiug to two individuals. 

The two largest teeth, of which one is represented in Figs. 1, 2, Plate 
XVIII, are probably from a median position in the mouth or jaws. They 
are symmetrical in form, and in outline arc transversely quadrate oblong with 
rounded angles. 

The ci"ovvn is prominently convex, with the front and lateral borders nearly 
straight, the back border slightly concave, and the angles rounded. Poste- 
riorly it is impressed with a moderately concave crescentoid sinus. The 
summit is crossed l)y a short transverse ridge, from which numerous ridges 
radiate. Descending on the sides of the crown the ridges branch, and about 
half way down terminate in a fine reticulation which extends to the borders 
of the tooth. The root is a quadrate plate with the same outline of form as 
the border of the crown. 

Three other specimens of the same parcel as the preceding appear to 
have been lateral teeth in relation to them in position in the mouth. They 
are nearly alike in shape and size ; one of them -being represented in Figs. 
3, 4. They are not symmetrical as in the larger teeth, and their onthne 
is more reniform. They are proportionately narrower at one side, and wider 
and more extended on a base beyond the conical elevation of the crown at 
the other side. The sinus is of less height, and the ridges of the crown 
are more convergent at the apex of the cone. The root appears to recede 
from the narrower side and reaches nearly to the edge of the crown on the 
opposite side. The remaining two teeth of the same parcel have the same 
character as those just described, but are considerably smaller. 

Measurements of some of the specimens are as follows : 



Breadth transversely 

Breadth antero-posteriorly . 
Height from bottom of root 





rig8.1,2. 




Figs. 3, 4. 


Lines. 


XijiM. 


Lines, 


Lines, 


22 


20 


m 


17 


V2i 


12J 


9 


9 


12J 


12 


8 


9 



Lines. 

1.3 



Of the two largest teeth, of the second parcel, which are nearly alike, one 
is represented in Figs. 5 and G. They are intermediate in character to those 



297 • 

previously described, being less symmetrical than the large teeth and more 
so than the smaller ones, and their crown is proportionately more prominent 
than in any of them. Of three teeth smaller than the former and succes- 
sively diminishing, that of intermediate size is represented in Figs. 7 and 8. 
They have the same form as the unsymmetrical ones of the first parcel, but 
have their crown proportionately much more prominent. 

The remaining two teeth are different in shape from the former. The 
larger one has tlie crown proportionately less prominent, with the central 
conical elevation less strongly radTate. The iimer side of the base forms an 
obtuse angle, and is strongly impressed toward the back border. The front 
border of the base of the crown is short, nearly straight, and forms with the 
oblique outer border an obtuse angle. 

The smaller tooth is represented in Figs. 9 and 10, and has nearly the same 
shape as the former, but the crown appears comparatively flat with a central 
nipple-like eminence, and the anterior and outer borders are more continuous. 

The measui'ements of the teeth are as follows : . 







Figs. 
5,6. 




Figs. 

7,8. 






Figs. 
9,10. 


Breadth of crown transversely 

Breadth of crown antero-posteriorly . . 
Height of crown from bottom of root. . 


Lines. 

7 


Lines. 

14 

8 

n 


Lines. 

6 

8 


Lines. 

^ 

5 
G 


Lines. 

7 
4 
4 


Linos. 

10 
G 
5J 


Lines. 
7 

U 
3i 



Several specimens of teeth of Plychodus Moitoni have been submitted to 
my inspection by Dr. William Spillinan, who obtained them from the Creta- 
ceous formation near Columbus, Mississippi. One of the teeth, of large size, 
and considerably worn at the summit of the crown, is represented in Figs. 
11 and 12. It is symmetrical in shape, but has a more reniforni ontline than 
the large teeth from Kansas. The anterior and lateral borders of the crown 
nearly form a semicircle, and the posterior border is deeply emarginate. 
The sinus is deeper than in the Kansas specimens, but the arrangement of 
the striations of the crown appear to be the same. 

Two other specimens, about half the size of the preceding, have nearly the 
same shape, but have their crown proportionately more convex at the fore 
part of the base. 
38 G 



298 



The measurements of the Mississippi specimens are as 


follows . 






Figs. 11, 1-2. 








Lines. 
20 
10 
9J* 


lAnes. 
12 
6| 


Lines. 

103 


Brofidth of cro VTTi foro mid aft 


7 




7 









* To wora summit. 

The Museum of the Academy of Natural* Sciences of Philadelphia contains 
nine specimens of teeth of Ptychodus Mortoni from the Cretaceous formation 
of Alabama. These in general resemble the symmetrical and unsymmetrical 
teeth above described. One of the specimens from Green County, Alabama, 
is represented in Figs. 13, 14. Its sinus is more sharply triangular than in 
the previous specimens. 

Another tooth, approaching in size the largest Kansas specimens, has a 
more distinct conical ridge on the summit of the crown from which the other 
I'idges radiate. A third tooth nearly resembles the Kansas specimen repre- 
sented in Figs. 3, 4, and has the summit of the crown worn away, as in the 
large Mississippi specimen, represented in Figs. 11, 12. 

Measurements of .Alabama specimens of teeth areas follows: 



Figs. 1.3, 14. 



Breadtli of crowu transversely 

Breadth of crown fore ami aft 

Height of crown from bottom of root. . 



Lines. 
16 
lOi 
10^ 



Lines. 

14* 
9 



Lines. 

16 

9 



Lines. 
13 

7 



Lines. 
9 



Ptychodus occidentalis. 

A peculiar species, to which the above name has been given, is indicated 
by specimens of teeth discovered by Dr. John L. Leconte in an ash-colored 
chalk of the Cretaceous formation a few miles east of Fort Hays, Kansas. 

The most characteristic, and at the same time the largest specimen, is 
represented in Figs. 7, 8, Plate XVII, of the natural size. 

The shape of the tooth and the arrangement of the ridges of the crown 
are quite different from what they are in the preceding species. The tooth 
is symmetrical, as in the largest teeth o? Ptychodus Mortoni., but it is propor- 
tionately of less brt'adtli transversely, and also higher. 



299 

The crown Ibniis a promiueiit cone with evenly sloping sides, and with a 
t rails versel_y oblong square base narrowing a little posteriorly. The posterior 
sinus t)t the crown comports in its height and breadth with the proportions 
of the Ibrmer. The principal ridges of the surface of the crown cross the 
summit and posterior slope transversely. Descending, they branch in a 
divergent manner and anastomose, so as to form a comparatively coarse retic- 
ulation, extending to the borders of the crown. The reticulation covers the 
anterior slope of the crown and the sinus posteriorly. The direction and 
arrangement of the ridges resemble those in the European Ptychodus decur- 
rens, but in this the principal ridges are much coarser and more widely 
separated. The root is mutilated in the specimen. The transverse diam- 
eter of the crown is 14 lines ; its fore and aft diameter and its height about 
1 inch. 

Figs. 15, 16, Plate XVIII, represent two views of a small tooth, wh.ich 
may probably belong to the same species. It is unsymmetrical, and is worn 
away at the summit of the crown. The latter is proportionately less promi- 
nent than in the large tooth, but has its ridges arranged in the same general 
manner. The root is very thick in comparison with the size of the tooth. 
The transverse diameter of the crown is 7i lines ; the fore and aft diameter 
J inch. 

Of five remaining specimens, one is a smaller and unworn tooth nearly 
like that last described. Its crown is 5 lines wide and 4 lines from before 
backward. 

The specimen represented in Fig. 17 is more symmetrical, and nearly 
resembles in shape the smaller symmetrical teeth of Ptychodus Mortoni, as 
represented in Figs. 13, 14. The apex of the crown is not so pointed, but is 
prolonged fore and aft in an acute ridge, and the rugae of the surface are not 
convergent, but cross the summit in the usual transverse manner of the otiier 
teeth. The breadth of the crown in this specimen is 4| fines ; the antero- 
posterior diameter 3f lines. 

The remaining teeth, of which the largest is represented in Fig. 18, have 
a transversely ovoidal crown slightly elevated to one side of the center. The 
surface is crossed by rugae in the same manner as in tlie large tepth. 



300 



The ineasiirciiioiils ol'tln^ three spi'oimeus aro 


a^ i" 


)ll()ws : 






■ 


Liues. 


Liues. 


Liues. 


Transverse diameter of the crown . . 




14 


o 


Antero-posterior diameter of the crowu 


IJ 





Ptychodus Whippleyi. 

Marcon, in his Geology of North America, describes and figures a tooth 
from the Cretaceous formation near Galisteo, New Mexico, and refers it to a 
peculiar species under the above name. 

A similar tooth submitted to my inspection by Dr. Benjamin F. Slnimard, 
from the Cretaceous rocks of Texas, is represented in Figs. 19, 20, Plate 
XVIII. It is remarkable for the abrupt nipple-like prolongation of the 
crown. 

The tooth is unsymmetrical, and probably held a lateral position in the 
series. The base of the crown is quadrate, witli the fore and outer borders 
forming a single curve, while the other borders form a nearly right angle. 
The nipple-like eminence of the crown inclines, as I suppose, outwardly. 
The posterior sinus is shallow. The rugae of the surface of the crown cross 
the summit transversely and diverge and branch descending upon the sides of 
the cone. They are comparatively feeble, but this condition may be partially 
due to friction. The surface of the base of the crown appears rather nodu- 
lated than reticulated. 

The breadth of the tooth at the base of the crown is 7 lines transversely 
and fore and aft ; its height from the bottom of the root 8 lines. 

The tooth resembles that of Ptychodus altior of Agassiz, from the chalk of 
Sussex, England, as represented in Fig. 10, Plate XXX, of Dixon's Geology 
of Sussex. 

ACRODUS. 

This extinct genus of cestraciont sharks, first described by Agassiz, was 
represented in Europe l)y many species whose remains occur in the various 
formations from the Permian to the Cretaceous inclusive. 



ACEODUS HUMILIS. 

A specicss to which this name has l)een given is indicated by an isolated 



301 

tuoth represented in. Fig. 5, Plate XXXVII, magnifieil 1^- diameters. The 
specimen was obtained from the yellow limestone of the Cretaceous series, 
near Vincentown, Burlington County, New Jersey, and it belongs to the 
Museum of the Academy. The erown of the tooth is 7^ lines by 2J lines. 
The extremities arc angular; the sides nearly straight or in the feeblest 
degree sigmoid. The upper surface is convex; and its median ridge is almost 
obsolete. The secondary ridges, proceeding transversely from the former, 
become branched and finely reticulated at the boundaries of the crown. 
The groove on the inner side of the latter, for co-adaptaticni to the contig- 
uous tooth, is about three-fourths of a line in width. The fang or con- 
tracted base of the tooth is about half the breadth of the crown. 

Professor Emmons has represented the tooth of an Acrodus in Fig. 97 of 
his Report of the North Carohna Geological Survey for 1858, which he attrib- 
utes to the Miocene Tertiary. If it really pertains to this formation, it indi- 
cates the latest known species of the genus. The species has been named 
Acrodus Emmonsi 

GALEOCERDO. 

Galeoceedo falcatus. 

The teeth of Galeocerdo are nearly as broad as they arc long, and the root 
is but moderately notched. The anterior border of the crown is strongly 
arched and oblique ; the posterior border is shglitly curved and nearly verti- 
cal, but is abruptly prolonged backward at its base. The border's of the 
crown are serrated ; the point is somewhat acuminate. 

Teeth frgm the chalk formations of Europe figured in the " Poissons Fos- 
siles," and ascribed by its illustrious author to half a dozen different species, 
are, with reason, by Reuss referred to a single one with the name of Corax 
heterodon. As Agassiz, according to Gibbes, does not now consider Corax 
different from Galeocerdo, I have used this name, together with the earlier 
specific one of falcatus, to represent the Corax heterodon of Reuss. 

Many specimens of well-preserved teeth, submitted to my examination, 
from various locaUties of the American Cretaceous formation, appear to belong 
to Galeocerdo falcatus. The variations in the form and size of different teeth 
I think are sufficiently accounted for from the difference of position the teeth 
occupied in the jaws and upon difference in age. 

Figs. 29 to 31, Plate XVIII, represent three of these teeth, obtained with 



302 

others by Dr. George M. Sternberg, United States Army, from the vicinity 
of Camp Supply, on the North Canadian River, Indian Territory, probably 
from a formation of Cretaceous age. 

Their apparent specific identity with the teeth of Galeocerdo falcatus of 
Europe is seen by comparing the figures with Fig. 43, taken from a tooth 
imbedded in a block of chalk from Sussex, England. 

Figs. 32 to 36 represent a series of similar teeth obtained, with many others 
of the same character, by Dr. William Spillman, from near Columbus, Mis- 
sissippi. 

Figs. 37 to 40 represent smaller teeth, which I suspect to belong to the 
same species, found by Dr. John L. Leconte, about three miles east of Fort 
Hays, Kansas. Similar specimens were also obtained by Dr. Hayden, in 
bed No. 2 of the Cretaceous rocks, near the mouth of Vermilion River, 
Kansas. 

Figs. 41, 42 represent small teeth, likewise of the same species, obtained 
by Dr. Shumard from the Cretaceous Ibrmation of Texas. 

OXYRHINA. 

The teeth of Oxyrhina have a simple, compressed demiconical crown, with 
sharp borders, and without lateral denticles. 

OXYEHINA EXTENTA. 

Figs. 21 to 23, Plate XVIII, represent specimens of teeth of an Oxyrhina 
discovered by Dr. George M. Sternberg, United States Army, in the vicinity 
of Camp Supply, on the North Canadian River, Indian Territory. Figs. 24, 
25 represent similar teeth found by Dr. William Spillman in the Cretaceous 
formation near Columbus, Mississippi. These teeth differ especially, from 
those of other species previously described and figured, in the greater pro- 
portionate extension laterally of the base of the ci-own. They most nearly 
resemble the teeth of the Oxyrhina Mantelli of the chalk of Europe. 

In the Museum of the Academy of Natural Sciences of Philadelphia there 
is a specimen of an Oxyrhina tooth in a block of chalk from Sussex County, 
England, resembling those just described in the unusual extension laterally 
of the crown. If this specimen pertained to O. ManteMi, it is probable that 
the specimens from Mississippi and the Indian Territory do likewise. It 
was not until after I had described the latter under the above name that I 



303 



noticed the specimen from the English chalk. My comparisons had been 
made with the figures of Agassiz, Dixon, and Reuss, and in none of" these do 
the teeth exhibit so conspicuous a lateral extension of the base of the crown 
as in the American specimens and the English chalk specimen of our Museum. 
An exception to this statement may be made in reference to Fig. 26, Plate 
XXX, in Dixon's Geology of Sussex, representing a tooth, which is rcferi-ed 
to Lamna acuminata. 

Measurements of the specimens referred to Oxyrhina extenta are as follows: 



Specimens represented in Pljite XVIII. 



Vis.. 21. 



FiK. 2-i. 



Fiff. 23. 



Fig. 24. 



Fiff. 25. 



Lines. 



Length from notch of root . 
Length of crown at middle 
Breadth of crown at base . 

Breadth of root 

Thickness of root 



9 

12 

5 



IJncs. 
12 

8- 
15 
17 

4.^ 



Lines. 

12 
13 
4i 



Lines. 

14 
12 

18 



Lines. 
10 

13 
14 

4 



LAMNA s. OXYRHINA. 

The teeth of Lamna are in general . characterized by the long, narrow 
crown, with a single denticle on each side of the base, and a strong root with 
narrow branches separated by a deep notch Those of Oxyrhina usually 
have a broader crown without lateral denticles, and also have a broader root 
with a shallower notch. In both genera, however, the proportion of breadth 
to length, and most other characters, except the presence or absence of the 
lateral denticles, vary in different parts of the jaws. In both, the side teeth 
are wider than those in advance, the disproportion usually being greater in 
Oxyrhina than in Lamna. Some of the teeth in the two genera so nearly 
assume the form of one another, that when isolated fossil teeth of either are 
•found without the base it is sometimes difficult to know to which to refer 
them. 

A number of times I have seen specimens of teeth, reputed to have been 
derived from the Cretaceous formation, which so closely resemble those of 
certain Tertiary species of Lamna, except in the possession of lateral denti- 
cles, that I have suspiciously regarded-them as pertaining to the same. The 
absence of denticles I tlionght might be accidental or abnormal. The report 
that the teeth had been found in a Cretaceous formation I suspected might 



304 

be a mistake ; or, if they had, that they were, perhaps, accidental in their 
occurrence in that formation, and had probably been derived from some con- 
tiguous Eocene deposit. The frequent repetition of the same thing has led 
me to view the specimens as having really pertained to Cretaceous fishes. 
The absence of the lateral denticles would refer the teeth to the genus Oxy- 
rhina, and the general form and other characters rather to the genus Lamua. 
May the teeth not be regarded as having belonged to Oxyrhina ancestors of 
some of the later Lamnse 1 
,.Fig. 44, Plate XVIII, represents a tooth which lies iml^edded in a portion 
of gray rock, obtained by Dr. John L. Leconte from the Cretaceous forma- 
tion three miles east of Fort Hays, Kansas. The specimen is perfect and 
unabraded. In all respects it is like the teeth of Lamna cuspidata of the 
early Tertiary deposits, except that it is devoid of lateral denticles, and pre- 
sents no trace of ever having possessed them. 

Fig. 45 represents a tooth, which lies in a block of chalk, from Sussex, 
England. The siiecimen is preserved in the Museum of the Academy of 
Natural Sciences of Philadelphia. Like the former, it closely resembles the 
teeth of L. cuspidata, but exhibits no trace of lateral denticles. 

Figs. 46, 47 represent two teeth which the writer found with the skeleton 
of Hadrosaunis Foulkii and shells of Exogyra costata, Ammonites placenta, 
&c., in clay near Haddonfield, Camden County, New Jersey. These speci- 
mens, unworn and perfect, except in positions having no relation with the 
point in question, are identical in character with the teeth of Lamna elegans 
of the early Tertiary deposits, except that they exhibit no trace whatever of 
the existence of lateral denticles. 

Figs. 48, 49 represent two teeth selected from eight specimens obtained 
by Dr. AVilliam Spillman from the Cretaceous formation near Columbus, Mis- 
sissippi. Most of the specimens are complete and well preserved, and in no 
instance exhibit traces of lateral denticles, while in all other respects they are 
like the teeth of L. elegans. 

Seven specimens of teeth from the Cretaceous formation of Green County, 
Alabama, presented to the Academy of Natural Sciences of Philadelphia by 
Dr. Joseph Jones, also agree with those of L. elegans, except that they have 
no lateral denticles. 

In a collection of similar teeth, presented to the Academy by "William M. 
Gabb, in all the specimens retaining the root, twenty in number, the lateral 



305 

denticles are absent. Most of the teeth appear slightly water-worn, but the 
best of them exhibit no trace of the lateral denticles. These specimens were 
obtained by Mr. Gabb from the Cretaceous green sand of Mullica Hill, Glou- 
cester County, New Jersey. 

Fig. 50 represents a tooth which lies partially imbedded in a fragment of 
gray sandstone, obtained by Professor Hayden from the Cretaceous deposit, 
indicated by him as No. 2, near the mouth of Vermilion River, Kansas. In 
the attempt to dislodge the tooth from its matrix the ends of the root were 
bi'oken off, but it is otherwise complete. It also appears not to have pos- 
sessed lateral denticles, but otherwise is like the teeth of X. elegans. 

Roemer describes and figures a tooth, (Kreidebikkmgen v. Texas, page 29, 
Plate I, Fig. 7,) mider the name of L. Texana, from the Cretaceous forma- 
tion of Texas. The figure represents wkat appears to be a perfect tooth 
without lateral denticles, and otherwise resembles those of L. elegans. 

Dr. B. F. Shuraard also submitted to my inspection several teeth from the 
Cretaceous formation of Texas resembling those of L. elegans, but in these 
the root was broken off, excepting on one side of one specimen, and in this 
no lateral denticle existed. 

Notwithstanding all that has been stated above, I must add that I have 
noticed among collections of teeth of L. elegans from Tertiary formations 
specimens in which the latei-al denticles were feebly developed, and others in 
which they were entirely absent. In some of the latter, traces of their acci- 
dental detachment were perceptible, but in others I could see none. 

It would appear, however, from the facts thus given, that during the Cre- 
taceous period there existed two species of sharks in which the teeth resem- 
bled those of L. ciisjndata and L. elegans of the Tertiary period, except that 
the teeth possessed no lateral denticles. The two Cretaceous sharks were 
probably the ancestors from which the species just named were evolved. 

OTODUS. 

Otodus divaricatus. 

Among a small collection of fossils submitted to me for examination by Dr. 
William Spillman, of Columbus, Mississippi, there is a specimen of a shark- 
tooth of rather peculiar character, which is represented in Figs. 26 to 28, of 
Plate XVIII. The specimen is labeled "lime formation," Texas, and noth- 
39 G 



306 

ing is further known in relation to its locality, but I suspect it to be of Cre- 
taceous age. Of known species, it bears most resemblance to the teeth of 
Otodus semiplicatus, Ag., of the chalk of Europe. It also has some likeness 
with a tooth from the chalk of France, represented in Fig. 11, Plate LXXVI, 
of Grervais's Paleontologie Franqaise. 

The crown forms a narrow demicone, with an expanded base supporting a 
pair of inwardly-diverging denticles. The surface of the principal cone near 
the base is plicated. The root is thick and deeply notched, and extends pos- 
teriorly more than half the length of the tooth. The anterior surface of the 
crown in the median line is as long as the base is wide, and is about one-fifth 
greater than the posterior surface. 

The measurements of the specimen are as follows : 

Lines. 

Length of tooth at raiddle 16 

Length from ends of the root 21 

Breadth at ends of the root 15J 

Length of crown iu front 13 

Length of crown behind 10 

Breadth of crown at base 12g 

Holocephaii. 

EDAPHODON. 

In the extinct chimseroid fish Edaphodon the inferior maxiliarics are pro- 
duced anteriorly in a long beak, and the superior maxillaries are provided 
with three large dental areas. In the allied genus Ischyodus the inferior 
maxillaries are not prolonged in a beak, and the upper ones are provided with 
four large dental areas. 

Edaphodon mikificus. 

A species under the above name was indicated by the author in the Pro- 
ceedings of the Academy for 1856, page 221. It was founded on eight speci- 
mens of maxillaries obtained from the Cretaceous green sand of Burlington 
County, New Jersey, by Professor (jeorge H. Cook, during the State geo- 
logical survey. 

The inferior maxillaries, represented in Figs. 6 to 9, Plate XXXVII, are 
about twice the length of the depth. The two rami converge in a curve, and 
end together in a long, bird-like beak, (Fig. 6.) 

The outer surface (Fig. 7) of each ramus is lozenge-like in outline, defined 



307 

by a concave upper border, a convex anterior border, a short, oblique, poste- 
rior border, and a convex lower border. The surface is concave longitu- 
dinally, and is convex transversely in front and behind, and concave in the 
middle. 

The inner surface (Fig. 8) is flat transversely, slightly convex longitudin- 
ally, and with the fore and back borders prominent. It is moderately stri- 
ated in the length, and at its upper part presents a symphysial bevel, extend- 
ing the length of the beaked portion of the bone. 

The oral surface (Fig. 6) on the beak is concave fore and aft, and at the 
back half of the bone forms a lozenge-like plane sloping inwardly, and having 
the outer border elevated. The sloping plane exhibits at its fore part inter- 
nally a large cordiforni dental area, with the notch at the base of the beak. 
Externally to this area, near the fore part of the crest defining the outer part 
of the sloping plane, there is a second much smaller elliptical dental area. 
These two areas are separated by a groove, widening forward upon the oral 
surface of the beak, where it presents a third dental area. This is the third 
in size, is oval in form, and is situated just in advance of the outer part of .the 
largest dental area. 

A fourth area, smaller than the others, occupies the back extremity of the 
symphysial bevel to the inner side of the anterior part of the largest dental 
area. The dental column which forms this fourth area produces the prom- 
inent ridge defining the inner surface of the ramus mandibuli posteriorly. 

Beside these dental areas, two or three others are observed at the end of 
the beak. One of them curves from the symphysis outward and backward on 
the outer edge of the point of the beak. Another smaller oval one is situated 
at the edge of the symphysis behind the commencement of the former. In 
one specimen a still smaller oval area is situated just behind the outer end of 
the curved area, but in the other specimens it appears not to be distinct from 
the latter. 

The dental areas in the fossils appear as depressed and decomposed, 
friable, white, chalky tracts, with harder calcigerous tubules of the vaso- 
dentiue projecting from the surfaces. The tubercular eminences originally 
occupying the position of the areas and terminating the dental columns 
have disappeared, leaving depressed surfaces. The vaso-dentiual columns 
corresponding with the areas on the triturating surface are visible at the 
posterior-inferior extremity of the mandibles, as seen in Fig. 9. 



308 

The upper maxillaries, represented in Figs. 10 to 12, bear a near resem- 
blance to those of Edaphodon BucJdandi and E. Icptognathus, as represented 
in Tab. 40 d, of the third volume of the Atlas of Agassiz's Poissons Fossiles. 

The outer surface (Fig. 11) of each maxilla is a broad, sloping plane, the 
inner surface a vertical plane. The upper surface is also flat, but is occupied 
at its inner back pai't by a wide, deep gutter, ending forward in a pit. 

The palatine surface (Fig. 10) of the two bones conjoined at its back part 
forms a wide, transverse concavity, nearly flat in the middle, but curving 
downward at the outer part. The palatine surface inclines forward to the 
anterior subacute termination of the bones. The lateral border of each max- 
•illa at the palatine surface is strongly sigmoid. 

Three large dental tubercles occupied the palatine surface of each max- 
illa, indicated in the fossils, as seen in Fig. 10, by tliree depressed areas of 
white, decomposing vaso-dentiue. The largest area is posterior and internal. 
It is broken at its back part in the fossils, but, in the entire condition, appears 
to have been reniform in outline. Immediately in advance of this area is 
another with an oblong cordiform outline ; and external to the largest one is 
the third area, about as long as this, but not more than half the breadth, and 
having a clavate outline. 

The dental columns corresponding with the three dental areas are seen 
at the back of the maxillae, the largest one below the position of the two 
smaller ones, as represented in Fig. 12. 

The measurements of the specimens are as follows : 

Inferior maxillary. 

Lines. 

Extreme length of bone C4 

Leugth of beak along the symphysis 40 

Length of anterior border of ramus 44 

Leugth of posterior or upper border bcack of the beak 26 

Width of inner surface 26 

Width of upper surface back of the beak .* 24 

Width of the large posterointernal deutal area 13* 

Estimated breadth fore and aft 10 

Width of external dental area ~ 7 

Estimated breadth fore and aft , 3 

Diameter of anterior deutal area fore and aft ., 4 

Diameter of same transversely - 3 

* The size of tlie deutal areas is iu some measure uncertain, as iu some cases they appear to havo 
been more or less estomled in the fore and aft diameter by fracture over the position of the dental 
columus. 



309 

Superior maxillary. 

Lines. 

Extreme length of bone 5S 

Length 6T bone internally 43 

Bi'eadth i>osteriorly 23 

Diameter fore and aft of large postero-internal dental area 18 

Diameter of same transversely , 12 

Diameter fore and aft of anterior dental area 11 

Diameter of same posteriorly and transversely 5 

Diameter fore and aft of external dental area 16 

Diameter transversely of the same where widest 5 

EUMYLODUS. 

EuMYLODUS LAQUEATUS. 

Among some fossils from the Cretaceous sandstone near Columbus, Missis- 
sippi, submitted to my examination by Dr. William Spillman, there is a spec- 
imen of the maxillo-dentary apparatus of a chimaeroid fish, related with 
Ischyodus, but apparently distinct from that genus. The specimen is repre- 
sented in Figs. 21, 22, Plate XIX, and Figs. 13, 14, Plate XXXVII. It 
most resembles, in its general form, the mandible of Ischyodus, as repre- 
sented in Fig. 20, Tab. 40, of /. Townsendi, and Fig. 16, Tab. 40 c, of I. 
Agassizi, of the third volume of the Atlas of the Poissons Fossiles. 

The bone is of denser character than the corresponding one of Edaphodon, 
and in this respect and several others is more like that of Leptomylus, de- 
scribed by Professor Cope. 

The outer surface (Fig. 14, Plate XXXVII) is nearly Hat, but slightly 
depressed below, and bent outwardly behind from the triturating surface. 
The inner surface (Fig. 21, Plate XIX) is fluted ; the anterior third presents 
a succession of three curved ridges separated by two grooves ; the median 
third forms a wide, concave groove ; and the posterior third forms a nearly 
square plane, sloping from the triturating surface backward and inward, and 
defined by a subacute border from the outer surface of the bone. 

The anterior border of the mandible appear-s as curved cylindroid termina- 
tion of the bone. No appearance of a distinct symphysial surface exists. 

The oral surface (Fig. 22, Plate XIX) is uneven, and conforms in its out- 
line with "the inner and outer faces of the bone. The anterior most promi- 
nent portion is convex, and exhibits some scratches and polisli, due to its 
masticating function. Its posterior two-thirds incline from a median dentary 
ridge, moderately without and behind, but steeply within. 



310 

The dcntary ridge is near the median line of the oral surface, extending 
about half its length, but nearer its posterior than anterior extremity. As 
seen in Fig. 13, Plate XXXVII, it appears to be composed of the prominent 
tubercular extremities of three connate columns, of which the back two 
appear oval, and the anterior one rather clavate in outline. 

The measurements of the specimen are as follows : 

Lines. 

Length or depth of the anterior border 32 

Length or depth of the posterior border . '. 11 

Thickness of the anterior column or border 6 

Thickness at the second ridge of the inner surface 6^ 

Thickness at the third ridge of the inner surface SJ 

Thickness at the middle concavity of the inner surface 7^ 

Thickness at the commencing ridge of the posterior slope of the inner surface. . . 10 

F5re and aft extent of triturating surface 36 

Length of dental tract 19 



NOTICE OF SOME REMAINS OF FISHES FROM THE CARBONIF- 
EROUS FORMATIONS OF KANSAS. 



The remains described below were obtained by Dr. F. V. Haydeu and 
Mr. F. B. Meek in the summer of 1858, and were originally noticed by the 
writer in the Proceedings of the Academy of Natural Sciences of Philadel- 
phia in January, 1859. 

Plagiostomi. 

CLADODUS. 

Cladodus occidentalis. 

The extinct genus of cartilaginous fishes, Cladodus, was first characterized 
by Agassiz from isolated teeth from the Coal-formation of Europe. A 
species of the same genus is indicated by a fragment of a tooth discovered 
by Messrs. Hayden and Meek in the upper Coal-measures of Manhattan 
Kansas. 

The specimen has lost one-half its base, a large portion of its principal 
cusp, and the points of the lateral cusps, but sufficient remains to give us a 
correct idea of the form of the perfect tooth, as represented in Figs. 4 to 6, 
Plate XVII. 

The base of the tooth is oblong in outline, with the inner border some- 
what angular and the outer one concave. Its upper inner surface slopes from 
the cusps, and near its margin, a short distance from the extremities, supports 
a pair of oval tubei'cles. Similar protuberances occupy a position beneath 
the base externally. 

The median or principal cusp of the tooth is elongated demiconical, with 
acute lateral edges. The inner convex surface of the cusp at its base exhibits 
sharp, oblique folds or striae, as represented in Fig. 4. The outer less convex 
or nearly flat surface is smooth, except a few vertical wrinkles at its base. 

The lateral denticles on each side of the principal cusp are two, of which 
the outer is the larger. 



312 

In its perfect condition the tooth has approximated I4 inches in length, 
and about 1 inch in breadth at l)ase. 

A simihar tooth from the coal-measures of Illinois has been described 
under the name of Cladodus mortifer by Professor Newberry, in the second 
volume of Worthen's Geological Survey of Illinois, published in 18G6. Mr. 
Orestes St. John has likewise described some teeth of the same species from 
the coal measures of Nebraska, in the Proceedings of the American Philo- 
sophical Society for 1870, and in Hayden's Report on the Geological Survey 
of Nebraska, published this year. 

XYSTRACANTHUS. 

Xystracanthus arcuatus. 

A second cartilaginous fish of the Coal-period is indicated by a remarkable 
dorsal spine, discovered by Messrs. Meek and Hayden in the Upper Carbon- 
iferous rocks of Leavenworth City, Kansas. The specimen, represented in 
Fig. 25, Plate XVII, lies partially imbedded in a piece of yellowish lime- 
stone, also containing a few minute crinoid segments. The point of the spine 
and its root of insertion are destroyed, and the specimen is otherwise muti- 
lated and appears somewhat crushed, but it is sufficiently characteristic to 
distinguish it from ichthyodorulites previously described. 

The spine is strongly curved, appears flattened at the sides, and is rounded 
at tlie borders. Its transverse section is narro\V ovoid, with the narrower 
extremity toward the convex border. The spine is longitudinally striated, 
and in its present condition the bone is brown and quite friable. The sides 
and concave border of the spine are furnished with white, shining, enamel- 
like tubercles of various sizes. The smaller ones are half ovoid ; larger 
ones are conical or half conical ; and the largest, which occupy the upper and 
lower part of the concave border, are crescentoid, and embrace the latter. In 
shape and attachment the larger tubercles remind one of minute polypori 
projecting from the stem of a tree. They are convex above, and flat, or 
slightly concave, below. 

PETALODUS. 
Petalodtjs alleghaniensis. 

Petalodus is another extinct genus of cartilaginous fishes, allied to our 
living sharks, which was originally characterized by Owen, and was also 
established on isolated teeth from the Carboniferous formations of Europe. 



313 

A species of the same genus, under the above uame, was described by the 
author in the Journal of the Academy of Natural Sciences for 1856, from a 
specimen found in the Coal-measures of Blair County, Pennsylvania. A sim- 
ilar tooth was also described and referred to the same species in the Pro- 
ceedings of the Academy for 1859, which was obtained by Messrs. Meek and 
Haydeu from the Upper Carboniferous formation of Fort Riley, Kansas. The 
specimen is represented in Fig. 3, Plate XVII. 

The crown is broad, and somewhat lozenge-shaped in outline. The base 
is bordered by a thick annulated ridge, arching downward toward the middle 
and moderately deflected at the extremities. The free border is sharp and 
somewhat arcuate, and the apex is slightly acuminate. The anterior sur- 
face of the crown slopes outwardly. The posterior deeper surface is concave 
at its lower median portion. The fang is about as long as the crown is exter- 
nally, but is not so wide. Its extremity is angular and everted. 

The measurements of the tooth are as follows : 

Lines. 

Length of tooth iu the entire condition about 19 

Breadth of crown at base 20 

Length of crown externally 9.^ 

Length of crown internally 12 

Length of fang externally 9^ 

Breadth of fang 14 

Similar teeth from the Coal-measures of Illinois have been described by 
Professor Newberry, under the name of Petalodus destructor, in the work 
above mentioned. Others have also been described or indicated, from the 
Coal-measures of Indiana, Iowa, and Nebraska, by Mr. St. John, likewise in 
the works above named. 

ASTERACANTHUS. 

ASTERACANTHUS SIDEEIUS. 

Incidentally, I take the opportunity of describing a fossil submitted to my 
examination by Professor J. M. Satford through Professor Hayden. It was 
obtained near Glasgow, Tennessee, and is reputed to be of Sub-carboniferous 
age. The specimen consists of a fragment of an ichthyodorulite, or fossil- 
iish spine, and is represented in Fig. 59, Plate XXXII. It appears to indi- 
cate a species of the extinct genus Asteracanthus, the remains of which had 
previously only been found in formations of later age than that above men- 
tioned. 

40 G 



314 

The fragment is from an intermediate position at the junction of the root 
and shaft, and is a little over 3 inches in length. It looks as if when in a 
complete condition it had been upwards of a foot in length, approximating 
that of the dorsal spine of A. ornatissinms. Broken off at both extremities, 
and also posteriorly, so as to leave no portion of the usual groove, it appears 
as a solid, porous bone-fragment, triangular in transverse section toward the 
apex, and oblong toward the root. 

The sides of the shaft are closely studded with mammillary tubercles, 
arranged in rows directed upward and forward. The tubercles incline in the 
same direction, and have their sides longitudinally striated. Their summits 
are worn away, the extent of abrasion increasing, approaching the anterior 
border of the spine. 



SYNOPSIS OF THE EXTINCT VERTEBRATA DESCRIBED OR 
NOTICED IN THE PRESENT WORK. 



MAMMALIA. 

Carnivora. 

FELIS; 



FeLIS AUGUSTUS. * 

Leidy : Pr. Ac. Nat. Sc. 1872, 39. 

Described page 227 of the present work, and represented by Figs. 18, 19, 
Plate VII, and Fig. 24, Plate XX. From the Pliocene of the Niobrara 
River, Nebraska. 

Felis imperialis. 

Founded on an upper-jaw fragment, containing the second premolar tooth, 
from the Quaternary of California. Described page 228, and represented 
by Fig. 3, Plate XXXI. 

Canid^. 

CANIS. 
Cants indianensis. 

Leidy : Ext. Mam; of N. America 1SG9, 368. 

Canis primccvus. Leidy : Pr. Ac. "Nat. Sc. 1854, 200 ; Jour. Ac. Nat. Sc. 185G, 
III, 1G7, Plate XVII, Figs. 11, 12. 

Founded on an upper maxillary with teeth from the banks of the Ohio, 
near Evansville, Indiana. Also indicated by the ramus of a lower jaw 
from California. Quaternary. 

See page 230 for description of the latter specimen, represented by Fig. 2, 
Plate XXXI. 

Canis vafer. 

Leidy : Pr. Ac. Nat. Sc. 1858, 21 ; 1870, 109 ; Ext. Mam. of N. America 18G9, 3G8. 

Founded on jaw-fragments with teeth from the Pliocene of the Niobrara 
River, Nebraska, and Sweetwater River, Wyoming. 



316 

FAMILIES UNDETERMINED. 

PATRIOFELIS. 
Patriofelis ulta. 

Leidy : Pr. Ac. Nat. Sc. 1870, 10 ; Haydeu's Eep. Geol. Sur. Wyoming 1871, 344; 
Hayden's Eep. Geol. Sur. Montana 1872, 355. 

Founded on the mutilated rami of a lower jaw from the Bridger Eocene 
Tertiary, "Wyoming. Described page 114, and represented by Fig. 10, 
Plate II. 

UINTACYON. 

Probably the same as Miacis, described by Professor Cope in the Proc. 
Am. Phil. Soc. 1872, 470. 

UlNTACYON EDAX. 

Leidy : Pr. Ac. Nat. Sc. 1872, 277. 

Founded on the ramus of a lower jaw from the Bridger Eocene Tertiary 
of Wyoming. Described page 118, and represented by Figs. 6 to 10, 
Plate XXVII. 

UlNTACyON VORAX. 

Leidy : Pr. Ac. Nat. Sc. 1872, 277. 

Founded on a lower-jaw fragment from the Bridger Eocene Tertiary of 
Wyoming. Described, page 120, and represented by Figs. 11 to 13, 
Plate XXVII. 

SINOPA. 

SiNOPA RAPAX. 

Leidy: Pr. Ac. Nat. Sc. 1871, 115; Hayden's Eep. Geol. Sur. Montana 1872, 355. 

Founded on a lower-jaw fragment with teeth from the Bridger Eocene 
Tertiary of Wyoming. Described page 116, and represented in Fig. 44, 
Plate VI. 

SiNOPA EXIMIA. 

Indicated Ijy a lower-jaw fragment, described page 118, and represented 
in Fig. 45, Plate VI. From the Bridger Eocene Tertiary of Wyoming. 

MuSTELIDiE. 

LUTRA I 

LUTRA PISCINARIA. 

Indicated by a tibia, described page 230, and represented in Fig. 4, Plate 
XXXI. From (he Pliocene Tertiary of Idaho. 



317 

ARTIODACTYLA. 

Ruminantia. 

Camelid^. 

AUCHENIA. 

AUCHENIA HESTERNA. 

Founded on specimens of teeth described page 255, and represented in 
Figs. 1 to 3, Plate XXXVII. From the Quaternary of California. 

PROCAMELUS. s. Protocamelus. 

Procamelus occidentalis ? 

Leidy : Pr, Ac. Nat. Sc. 1858, 23, 89 ; Ext. Mam. K America 1869, 382. 

See page 258 of the present work, and represented by Figs. 21, 22, Plate 
XX. Pliocene of Nebraska and Texas? 

Pkocamelus robustus ? 

Leidy: Pr. Ac. Nat. Sc. 1858, 89; Ext. Mam. N. America 1SG9, 381. 

See page 259 of the present work. Pliocene of Nebraska and Texas. 

Procamelus virginiensis. 

Leidy : Pr. Ac. Nat. Sc. 1873, 15. 

Page 259, and represented by Figs. 26 to 29, Plate XXVII. Founded on 
teeth from the Miocene of Virginia. 

Procamelus ? niobrarensis. 

Megalomeryx niobrarensis ? Leidy : Pr. Ac. Nat. Sc. 1858, 24 ,• Ext. Mam. Da- 
kota and Nebraska 1869, 161, Plate XIV, Figs. 12 to 14. 

See page 260, under the name of Megalomeryx niobrarensis ? and repre- 
sented in Figs. 24, 25, Plate XXVII. Founded on teeth from the Plio- 
cene of the Niobrara River, and from L'Eau qui Court County, Ne- 
braska. 

CERVIDiS. 

LEPTOMERYX. 

Leptomeryx Evansl 

Leidy : Pr. Ac. Nat. Sc. 1853, 394 ; 1870, 112 ; Ext. Mam. N. America 1869, 383. 

Noticed from the Miocene of Oregon, page 216. Originally described 
from the Miocene of Dakota, 



318 

MERYCODUS 
Merycodus necatus. 

Leidy : Pr. Ac. Nat. Sc. 1854, 90, 157 ; 1857, 89 ; 1858, 23 ; 1870, 109; Ext. Mam. 
N. America 18G9, 382. 

Noticed from the Pliocene of Sweetwater River, Wyoming. Originally 
described from Bijou Hill and from Little White River, or the South 
Fork of White Earth River, Dakota. 

BoviDiE. 

BISON. 

Bison latifrons. 

Leidy: Pr. Ac. Nat. Sc. 1852, 117 ; Mem. Ext. Sp. American Ox in Smiths. Con- 
trib. 1852, 8; Ext. Mam. N. America 18G9, 371. 

Noticed from the Quaternary of California and Pennsylvania, page 253, and 
represented in Figs. 4 to 8, Plate XXVIII. 

Found in the Quaternary of Pennsylvania, Georgia, South Carolina, Ken- 
tucky, Mississippi, Texas, and California. 

Oreodontid^. 

OREODON. 

Leidy : Pr. Ac. Nat. Sc. 1851, 238. 
Merycoido(lo7i. Leidy : Pr, Ac. Nat. Sc. 1848, 47. 

Oreodon Culbertsoni. 

Leidy: Owens's Eep. Geol. Sur. 1852,548; Ext, Mara. N.America 1869,379; 
Pr. Ac. Nat. Sc. 1870, 67, 112. 

Noticed from John Day's River, Oregon, page 211, and I'epresented in 
Fig. 12, Plate VII. 

Professor Marsh has recently described some remains from the Miocene of 
Oregon, under the name of Oreodon occidentalis. (Am. Jour. Sc. May, 
1873.) He observes that it resembles O. Culbertsoni in most of its 
cranial characters, but differs materially in the large auditory bulltfi. 
From this, I suspect the remains, together with those I have described 
from Oregon under the last-mentioned name, belong to the species I 
have elsewhere named O. hullatus. 

Professor Marsh observes that, "in comparing the various species of Oreo- 
don, some new points in the structure of the genus were observed." He 
then gives in the formula of dentition the number. of incisors as f , canines 
T, premolars 4, molars f , and adds : " The caniniform tooth of the lower 



319 

jaw is clearly tlic first premolar, as Dr. Gill has stated.'' As may be 
seen by referring to pages 84 and 85 of the Extinct Mammalia of Dakota 
and Nebraska, although giving the formula of dentition of Oreodon as — 
incisors f, canines t, premolars I, molars t, I observe that the inferior 
canine is a transformed premolar, and that the inferior lateral incisor, as 
in other ruminants, is to be regarded as an incisiform canine. 

Okeodon superbus. 

Leidy : Pr. Ac. Nat. Sc. 1S70, 111. 

Described, page 211, and represented by Fig. 1, Plate I; Fig. 16, Plate II; 
and Figs. 7 to 1 1, Plate VII. From the Miocene of Oregon. 

MERYCOCHCERUS. 
Leidy : Pr. Ac. Nat. Sc. 1858, 24 ; Ext. Mam. N. America 18G9, 380. 

Merycochcerus rusticus. 

Leidy : Pr. Ac. Nat. Sc. 1870, 109. 

Described page 199, and represented by Figs. 1 to 3, Plate III ; Figs. 1 
to 5, Plate YII; and Figs. 9 to 11, Plate XX. From the Pliocene of 
Sweetwater River, Wyoming. 

AGRIOCHCERUS. 

Agriochcerus antiquus. 

Leidy : Pr. Ac. Nat. Sc. 1850, 121 ; Ext. Mam. N. America 1809, 381 ; Pr. Ac. 
Nat. Sc. 1870, 112. 

Noticed from the Miocene of Oregon, page 216. 

Agriochcerus latifrons. 

Leidy : Pr. Ac. Nat. Sc. 18G7, 32 ; 1870, G7 ; Ext. Mam. N. America 18G9, 381. 

Noticed from the Miocene of Oregon, page 216. 

Omnivora. 

SuiD^. 

DICOTYLES. 

DiCOTYLES PRISTINUS. 

Peccary. . Leidy : Pr. Ac. Nat. Sc. 1870, 112. 

Described page 216, and represented by Figs. 13, 14, Plale VII. From 



the Miocene of Oregon. 



320 

ANTHRACOTHERIDiE. 

ELOTHERIUM. 

Pomel : Bibl. Uuiv. Geneve, Archives, 1847, 307. 

Entelodon. Aymard : Mem. Soc. Agric., &c., dii Pay 1848, 240. 

Archa'otherium. Leidy : Pr. Ac. Nat. Sc. 1850, 90. 

Elotherium Morton 1 1 

Leidy : Pr. Ac. Nat. Sc. 1857, 175 ; Ext. Mam. N. America 1809, 388, 
Noticed from Wyoming, page 125, and represented by Figs. 28, 29, Plate 
VII. 

Elotherium imperator. 

Inferred from several mutilated teeth from the Miocene of Oregon, de- 
scribed page 217, and represented in Figs. 3, 4, Plate II, and Fig. 27, 
Plate VII. • Supposed to be the same as E. superhuin in Pr. Ac. Nat. 
Sc. 1870, 112. 

Elotherium ingens. 

Leidy : Ext. Mam. N. America 1SC9, 388 ; Pr. Ac. Nat. Sc. 1870, 112. 

Noticed from the Miocene of Oregon. Orighially from the Miocene of 
White River, Dakota. 

FAMILIES UNDETERMINED. 

HYOPSODUS. 

Hyopsodus paulus. 

Leidy : Pr. Ac. Nat. Sc. 1870, 110 ; 1872, 20 ; Hayden's Eep. Geol. Sur. Wyo- 
ming 1871, 354 ; Hayden's Eep. Geol. Sur. Montana 1872, 363. 

To this species, described page 75, I refer Figs. I to 9, 18 to 22, Plate VI. 
From the Bridger Eocene of Wyoming. 

Hyopsodus minusculus. 

This species, described page 81, is represented by Fig. 5, Plate XXVII. 
From the Bridger Eocene of Wyoming. 

MICROSYOPS. 

Leidy : Pr. Ac. Nat. Sc. 1872, 20 ; Hayden's Prelim. Eep. Geol. Sur. Montana 

1873, 3G3. 
Limnotlierium. In part of Marsh : Am. Jour. Sc. 1871, II, 42. 

MiCROSYOPS elegans. 

Limnothcrmm cicgans. Mar.sli : Am. Jour. Sc. 1871, 11, 43. 
Microsijops gracilis. Leidy : Pr. Ac. Nat. Sc. 1872, 20 ; Hayden's Prelim. Eep. 
Geol. Sur. Montana 1872, 363. 



321 

111 ]\Iicrosyops, six molar teeth imineiliatcly succeed the canine in tlie lower 
jaw. In the typical Limnotherium clegans seven molars occupy the same 
position. Described page 82, and represented by Figs. 14, 17, Plate VI. 
From the Bridger Eocene formation of Wyoming. 

MICROS US. 

MiCKOSUS CUSPIDATUS. ■ 

Leitly : Pr. Ac. Nat. Sc. 1870, 113. 

Sec page 81 ; not positively determined as a distinct species and genus. 
Represented by Figs. 10, 11, Plate VI. From the Bridger Eocene 
formation of Wyoming. 

HIPPOSYUS. 

HlPPOSYUS FORMOSUS. 

Leidy : Pr. Ac. Nat. Sc. 1872, 37. 

Described from a few isolated teeth, page 90, and represented in Fig. 41, 
Plate VI, and Figs. 1, 2, Plate XXVII. From the Bridger Eocene of 
Wyoming. 

HlPPOSYUS EOBUSTIOE. 

Notharctiis rohustior, Leidy : Hayden's Eep. Geol. Sur. Montana 1872, 304. 

Described page 93, and represented by Fig. 40, Plate VI. Fnnii the 
Bridger Eocene of Wyoming. 

HADROHYUS. 

HADROnVtlS SUPREMUS. 

Leidy : Pr. Ac. Nat. Sc. 1871, 248. 

Indicated by a mutilated tooth from the Miocene of Oregon. Described 
pa'ge 222, and represented by Fig. 26, Plate XVII. 

PERISSODACTYLA, 

Sulidungula. 

Equid^e. 

EQUUS. 
Equus major. 

Dekay: Nat. Hist. New York, Zool. 1842, 108. Leidy: Ext. Mam. N, America 

1869, .399. 
Eqmis complicatus. Leidy : Pr. Ac. Nat. Sc. 1858, 11 ; Ext. iMaiii. N. America 
1809, 399. 

41 G 



322 

Remains describud iiage 244, and represented by Fii^s. 3 to 18, Plate 
XXXIII. From the Quaternary of the United States. 

Equus occidentalis. 

Leidy : Pr. Ac. Nat. Sc. 1865, 94. 
f Equus. Von Me\-er: Palitoutographica 1867, 70. 

Equus cxcclsus. Leidy : Pr. Ac. Nat. Sc. 1868, 26 ; Ext. Mam. Dakota and Ne- 
braska 1869, 266, 400, Plate XIX, Fig. 39 ; XXI, Fig. 31. 
Equus imcifims- Leidy : Pr. Ac. Nat. Sc. 1868, 195 ; Ext. Mam. N. America 
1869, 400. 

Described page 242, and represented by Figs.. 1, 2, Plate XXXIII. From 
the Quaternary I of Nebraska, Idaho, California, and Mexico. 

* 

HIPPARION. 

HiPPARION SPECIOSUM ? 

Leidy: Pr. Ac. Nat. Sc. 1858, 27 ; Ext. Mam. N. America 1869, 401. 

See pages 247, 248, and Figs. 14, Ih, Plate XX. From the Tertiary of 
Texas. 

PROTOHIPPUS, s. MERYCHIPPUS. 

Peotohippus perditus (?) s. Merychippus mirabilis ? 

Protohippits perditus. Leidy: Pr. Ac. Nat. Sc. 1858, 20; Ext. Mam. N. America 

1809, 401. 
MerycM]>piis mirabilis. Leidy : Pr. Ac. Nat. Sc. 1858, 27. 

See pages 248, 249, 250, and Figs. 16, 20, Plate XX. From the Tertiary 
of Texas and Utah. 

PrOTOHIPPUS PLACIDUS. 

Leidy: Ext. :Mam. N. America 1869, 401. 

See pages 249, 250, and Figs. 17, 18, Plate XX. From the Tertiary of 
Texas. 

Anchitherid^. 
ANCHITHERIUM. 

Meyer : Jalirlnicli Miueralogie 1844, 298. 

Anchitherium Bairdi. 

Leidy: Owen's liep. Geol. Sur. Wisconsin, &c., 1852, 572; Ext. Mam. N. Amer- 
ica 18G9, 402 ; Pr. Ac. Nat. Sc. 1870, 112. 



323 

A full account of the remains of tlio species from the Mauvaises Terres of 
White River, Dakota, is given in the Extinct Mammalia of Dakota anil 
Nebraska, page 303. A notice of remains from Oregon is given page 
218 of the present work, and a tooth representing the species is given 
in Fig. 15, Plate VII. Miocene. 

Anchitheeium Condoni. 

Leidy : Pr. Ac. Nat. Sc. 1870, 112. 

Described page 218, and represented by Fig. 5, Phitc J I. From the 
Miocene of Oregon. . 

ANCHITIlERIUiM AGRESTE. 

Anchitherium. Leidy: Vr. Ac. Nat. Se. 1871, 101). 

Described page 251, and represented by Figs. IG, 17, Plate VII. From 

the Miocene ? of Montana. 

Anchitherium ? austeale. 

Described page 250, and represented l)y Fig. IJ), Plate XX. Fnnn the 
Tertiary of Texas. 

1 Anchitheehtm. 

Uquvs. Leidy : Pr. Ac. Nat. Sc. 18G8, 195. 
Uqmis parvulus. Marsh: Am. Jour. Sc. 1808. 

Noticed page 252, and represented by Fig. 23, Plate XX. From the 
Tertiary of Nebraska. 

PAL^OSYOPS. 

Leidy: Pr. Ac. Nat. Sc. 1870, 11.3 ; 1871, 111, 118, 197, 229; 1872, 168,211. 
" Haydeu's Prelim. Eep. Geol. Sar. Wyoming 1871, 355. Hayden's Prelim. Kep. 

Geol. Sur. Moutaiia 1872, 358, published April, 1772. 
Telmatherium. Marsh : Am. Jour. Sc. 1872, IV, 123, published iu ad\ance July 

22, 1872. 
Limnohyns. Mar.sh : Am. Jour. Sc. 1872, IV, 121, published iu advaucc July 22, 

1872. Cope: Pr. Am. Phil. See. 1873. 

Remains referable to the genus Palteosyops are the most common of Ihosi! 
of the larger extinct mammals occurring in the Bridger Eocene formation 
of Wyoming. The genus was originally indicated by characteristic spec- 
imens of teeth represented in Figs. 4, 5, Plate V, and Figs. 3 to G, Plate 
XXIII. Subsequently a numlscr of specimens were received from time 
to time and indicated in tiie Proceedings of the Academy from 1870 to 
1872, and in Professor Hayden's Preliminary Report of the Geological 8ur- 



324 

veys of Wyoming and Montana. In the report on Montana, published in 
April, 1872, the characters of the genus arc succinctly stated. Pateo- 
syops is described "as an odd-toed pachyderm, with the skeleton con- 
structed nearly as in the tapir. The thigh-bone possesses a tliird tro- 
chanter. The hind feet nearly repeat the construction of those of the 
tapir. The skull, with its large temporal fossae, high and thick sagittal 
crest, concave occiput, broad, convex face, resembled that of the related 
Palaeotherium. The teeth also agree in number and nearly in constitu- 
tion with those of that animal. The number of teeth altogether appear 
to .have been 44, consisting of 3 incisors, 1 canine, 4 premolars, and 3 
molars to the series on each side, above and below. The teeth in each 
jaw form a nearly unbroken arch, intervals existing only sufficient to 
accommodate the passing of the points of the large and bear-like canines. 

"The true molars have a resemblance to those of Palaeotherium. In the 
crowns of the upper true molars the inner constituent lobes are 
more completely isolated from the outer ones than in that genus, and the 
bottoms of the transverse valleys are proportionately of less depth. T//e 
last vpper molar of Palceosyops. has hut a single lobe to the inner part of 
the a'oio7i. , 

"In Palasotherium, the large premolars have the same form as the true 
molars, but are quite different in this respect in Palasosyops. In tlie 
iormer the crown of the upper premolars, except the first, is composed 
of four lobes, as in the succeeding molars. In Palasosyops the first pre- 
molar has a conical crown, the second a bilobed crown, "and the third 
and fourth have trilobed crowns. 

" The canines of Palaeosyops arc proportionately as large and of the same 
form as in the bears " 

In an article in the American Journal of Science, 1872, V, published iu 
advance July 22, 1872, Professor Marsh, after remarking that the type 
of the genus Palaeosyops is too imperfectly known to determine its more 
important characters, adds that, "in some ' specimens which agree best 
with the original description of paludosus, the last upper molar has tiro 
inner cones^ and to this group tlie name Palaeosyops may in future be 
restricted. Tlie other specimens have but a single infernal cone on tie 
last upper molar, and for the genus thus represented the name Limno- 
hyus is proposed." 



325 

In I his view Professor Cope has recently descrilted some remains of I'aln'- 
os3()[is under the name oi' Liiii/whi/us Iceoideiis. 

Teeth such as I have attributed to Palaeosyops arc comparatively abundant, 
but I have not yet had the opportunity of inspecting a specimen of a 
last upper molar, such as Professor Marsh ascribes to Palaeosyops, in 
which the inner side of the crown possesses two internal cones. That 
such exist there can be no question, as proved by Professor Marsh's 
description of Palaeosyops laticeps. 

Professor Marsh has described some remains which he refers to a genus 
wilh the name of Tehnatherium. Of this, he observes: "The dcniition 
of til's genus, so far as is known, appears to be similar to that of PalaBo- 
syops. The upper molar teeth have the inner cones more elevf^ted and 
more pointed than in Paheosyops, and the Ijasal ridge is well developed 
The last upper molar has l)ut a single internal cone." He also remarks 
that " the two may be i-eadily distinguished i)y the anterior portion of the 
skull, which in Telmatherium has the premaxillaries compressed, with an 
elongated median suture. The zygomatic arch is also much less strongly 
developed, and the squamosal portion of it is comparatively slender.'' Such 
differences are more likely to be of a sexual or individual character than of 
either specific or generic value. 

Since writing the preceding chapters we have attempted to give a restora- 
tion of the skull of Palseosyops in' Fig. 1, Plate XXXI, built up from a 
number of specimens. The cranium and face were mainly reconstructed 
from the specimens of Fig. 51, Plate XVIII, and Figs. 1, 2, Plate XXIV; 
the lower jaw from the specimen of Fig. 52, of the latter plate, and Fig. 
4, of the former plate. 

1. Pal^osyops paludosus. 

Leitly: Pr. Ac. Nat. Sc. 1870, 113 ; 1871,114,197,229; 1S72, 1G8; Hayilcii's 

Hep. U. S. Geol. Sur. Wyoiuiug 1S71, 355; llaydeii's itup. U. S. Geo). Sur. 

Moutaua 1872, 359. 
Pulmosijops. Leidy: Pr. Ac. Nat. So. 1871, 118. 
Ijbnnohijus hvvidens. Cope: Pr. Am. Pljil. Soc. 1873, article published in advance 

.January 31, 1873. 

The description of the species is given on page 28 of the present work. 
The specimens represented in Figs. 1 to 8, Plate IV; Figs. 4 to 11, 
Plate V ; Figs. 1 to 4, Plate XIX ; Figs. I to 7, Plate XX ; Figs. 3 tp 



32(1 

G, Plate XXIII; F'ijr.s. C, 7. Plate XXIV; and Fig. 5, Plate XXIX, are 

considered as pertaining ti) Palceosj/ops j'aludosus. 
A fine specimen, C(nisisti.iig of the greater part of" a skull, exhibited by 
Professor Cope to the Academy, and described I)y him under the name 
of Limnokyus Icevide.ns, appeared to me to be the same as Palceosyops 
paludosus. From the Bridger Eocene formation of Wyoming. 

2. Pal.eosyops major. 

Leidy: Haydeu's Prelim. Eep. Geol. Sur. Montana, April, 1872,359; Pr. Ac. ' 
Nat. Sc. 1872, 1G8, L'41. ' • 

■ Lymnohyus robustus. Marsh: Ain. Jour. Sc. 1872, IV, 121, published iu advance 
July 22, 1872. 

I am not convinced that this is a really distinct species from Palceosyops 
paludosus. A large number of specimens referable to the genus would 
indicate a considerable variation in the size of individnals, of which the 
more robust forms may have been males. The species is described on 
page 45. The specimens regarded as pertaining to it are represented 
in Fig. 8, Plate XX; Figs. 1,2, 7 to 12, 14 to 16, Plate XXIII; and 
Figs. 1 to 5, Plate XXIV. From the Bridger Eocene formation of 
Wyoming. 

3. PaLJEOSYOPS IIUMILIS. 

Leidy : Pr. Ac. Nat. Sc. 1872, IGS, 277. 

Probably a small species indicated ])y an upper molar, represented in Fig. 
8, Plate XXIV, and noticed page 58. From the . Bridger Eocene of 
Wyoming. 

4. PaL.EOSYOPS JUNIUS. 

Paltvosyops junior. Leidy : Pr. Ac. Nat. Sc. li?72, 277. 

Descril)e(l page 57. From tlie Bridger Eocene of Wyoming. 

LIMNOHYUS. 

LiMNOHYUS LATICEPS. 

Palmosyops laticeps. Marsh : Aui. Jour. Sc. 1872, 122. 

■Indicated page 58, and represented by Fig. 13, Plate XXIII. From the 
Bridger Eocene of Wyoming. 



327 ■ ■ 

HYRACHYUS. 

Hyuachvus agrarius. 

Lekly: naydon'.s rrclim. Rep. Geol. Siir. Wyoming 1871, ;557 ; Pr. Ac. Nat. Sc. 

1871, 229 ; 1872, 19, 108; Hayden's Eep. Geol. Siir. Montana 1872, 301. 
Hymchyus luiresfis. Leidy : Ilayden's Hep. Geol. Snr. Wyoming 1871, 357. 
Lophiodon liairdiimus. Marsh: Am. Jour. Sc. 1S71, II, .">. 

Tiie species is (leseribcd page GO of tlie present work, and specimens 
attributed to it are represented in Figs. 11, 12, Plate II; Figs. 9 to 18, 
Plate IV ; and Figs. 2.5, 2G, Plate XX. From the Bridgcr Eocene of 
Wyoniiug. 

Hyrachyus eximius. 

Leidy: Pr. Ac. Nat. Sc. 1871, 229; 1872,168; Haydcn's Rep. Geol. Sur. Mon- 
tana 1872, 301. 

Descrilied page- 66, and represented liy Figs. 19, 20, Plate IV ; Fig. 5, 
Plate XIX; and Figs. 9, 10, Plate XXVI. From the Bridger Eocene 
of Wyoming. 

Hyrachyus modestus. 

Leidy: Pr. Ac. Nat. Sc. 1872, 20; Hayden's Rep. Geol. Snr. Montana 1872, 301. 
LopModon modestus. Leidy : Pr. Ac. Nat. Sc. 1870, 109. 

Described page 67, and represented hy Fig. 13, Plate II. From the 
Bridger Eocene of Wyoming. 

Hyrachyus nanus. 

Leidy : Pr. Ac. Nat. Sc. 1872, 20 ; Hayden's Rep. Geol. Sur. Montana 1872, 361. 
°? LopModon nanus. Marsh: Am. Jour. Sc. 1871, II, 37. 

Described page 67, and represented by Fig. 14, Plate II ; Fig. 42, Plate 
VI; Fig. 11, Plate XXVI; and Figs. 21, 22, Plate XXVII. From 
the Bridger Eocene of Wyoming. 

LOPHIODON ? 

LOPIIIODON OCCIDENTALIS. 

Leidy : Pr. Ac. Nat. Sc. 1808, 232 ; Ext. Mam. N. America 1809, 391. 

Noticed as probably found in the Miocene of Oregon, page 218, and repre- 
sented in Fig. 1, Plate II. 

LOPHIOTHERIUM. 

LOPHIOTHERIIIM SYLVATICUM. 

Leidv : Pr, Ac. Nat. Se. 1870, 120. 



328 

Described pngc 69, and represented by Figs. 33 to 35, Plate VI. From 
the Bridger Eocene of Wyoming. 

RHINOCEROTIDyE. 

RHINOCEROS. 
Rhinoceros pacificus. 

Leidy: Pr. Ac. Nat. Sc. 1871, 248. 

Rhinoceros occidentalis. Leidy : Pr. Ac. Nat. Sc. 1870, 112. 

Described from teeth on page 221, and represented by Figs. 6, 7, Plate 
II, and Figs. 24, 25, Plate VII. From the Miocene of Oregon. 

Rhinoceros hesperiusI * 

Leidy : Pr. Ac. Nat. Sc. 1865, 17« ; 1870, 112; Ext. Mam. N. America, 1869, 390. 

Originally described from the ramus of a lower jaw from the Miocene 1 of 
California. Also supposed to be indicated by teeth described page 220, 
and represented by Figs. 8, 9, Plate II, from the Miocene of Oregon. 
In the May number of the American Journal of Science for 1873, Professor 
Marsh has noticed remains of rhinoceros, which he refers to two addi- 
tional species. One named Ji. annectens is founded on remains from the 
same formation as those of the preceding species. The other, named 
R. oregonensis, is reputed to have pertained to the Pliocene deposits of 
Oregon. 

families undetermined. 

AKCHIPPODUS. 

Anciiippodus riparius 

Leidy : Pr. Ac. Nat. Sc. 1868, 2.32 ; Ext. Mam. N. America, iu Jour. Ac. Nat. Sc. 

1869, VII, 403, Figs. 45, 46, Plate XXX. 
Palwosyops minor. Marsli : Am. Jour. Sc. 1871, II, 3C. 
TrogosHs castoridens. Leidy: Pr. Ac. Nat. Sc. 1871, 113; Ilay den's Eep. Geol. 

Sur. Moutiuia 1872, 360. 

Described page 71, under the name of Trogosus castoridcna, and also repre- 
sented as such in Figs. 1 to 3, Plate V. 

The genus Anchippodus was originally named from an isolated tooth from 
a Tertiary formation of Monmouth County, New Jersey. The speci- 
men is represented in Figs. 45, 46, Plate XXX, of the seventh volume 
of the Journal of the Academy for 1869, and is described on page 403 
of that work. It was not nntil after the description of the lower jaw 



329 

referred to Trogosus caslorldens, ov, page 71 oi' Uie present work, and 
represented under the same name in Figs. 1 to 3, Plate V, that I noticed 
the identity in character of the corresponding tooth. Previous (o the 
descrijition of the jaw referred to Trogosus, Professor Marsh had puh- 
Hshed a notice of a simiUir tooth under tlie name of Falcnosyops minor. 

It is not improbable, after all, that Trogosus may be distinct from Anchip- 
podus, for there are several genera which, while they have the inferior 
true molars alike, have the premolars and upper true molars quite differ- 
ent. While regarding Trogosus the same as Anchippodus, for the same 
reason I have considered Trogosus castoriclens the same' as Anch'qjpoclus 
riparlus, for the specimen upon which the latter was originally made known 
is identical in form and size with the corresponding tooth in the jaw of 
the former. Nor is it improbable that they are the same, for they were 
probably of contemporaneous age, and perhaps extended throughout the 
continent, as the American mastodon did at a later period. Specimen 
from the Bridger Eocene of Wyoming 

Anchippodus vetulus. 

Trogosus vetulus. Leidy : Pr. Ac. Nat. Sc. 1871, 229; Ilaydeii's Kep. Gcol. Snr. 
Moutaua 1872, 3G0. 

Noticed on page 75, under the name of Trogosus vetulus, and represented, 
with the name of Anchqrpodus vetulus, in Fig. 43, Plate VI. From the 
Bridger Eocene af Wyoming. 

NGTHARCTUS. 

NoTHARCTUS TENEBROSUS. 

Leidy: Pr. Ac. Nat. Sc. 1870, 114. 

Described page 86, and represented by Figs. 3(i, 37, Plate VI. From tlie 
Bridger Eocene of Wyoming. 

Proboscidea. 

ELEPHAS. 

Elepiias americanus. 

Dekay : Nat. Hist. New Tork, Zoo]., 1842, 1, 101, Leidy : Ext. Jlaiii. N. America 

1869, 398. 
Elvphas Golumbi. Falconer: Quart. Jour. Geol. Soc. 1857, .'!19, &{•,. 
Elcphas Texiauus. Owen : liep. Brit. Asso. 1858, 84, &c. 
Elcphas imperator. Leidy : Pr. Ac. Nat. Sc. 1858, 10. 

42 G ' 



330 

• Eucleplias Jaclsoni. Briggs and Foster : Caiiail. Nat. and Geol. 1SG3, 135, 147. 
Eitclejjhas Columhi. Falconer: Pahi'ont. Mom. ISGS, II, 211 to 231. 
Elcphas. Von Meyer : PaU-coutograpliica, 18G7, 70, Plate VII, Figs. 7, S. 

See page 238. Remains noticed from New Mexico and Texas. 

MASTODON. 

Mastodon americanus. 

Leidy: Pr. Ac. Nat. Sc. 1868, 175. For synonymy, see Extinct Mammalia of 
North America 1809, 392. 

Some remains described or noticed page 237, and represented in Figs. 5, 

6, Plate XXII, and Fig. 9, Plate XXVIII. 
Remains of the common American mastodon are found \i\ the Quaternary 

formation throughout the United States. 

Mastodon mirificus. 

Leidy: Pr. Ac. Nat. Sc. 1858, 10; 1870, 67; Ext. Mam. Fanna of Dakota and 

NebraskalSCO, 249, 390. 
Mastodon (Tetralophodon) mirificus. Leidy: Pr. Ac. Nat. Sc. 1858, 10. 

Remains originally described from the Pliocene of the Loup Fork of Platte 
River. Also reported to occur on the Niobrara River, Nebraska. No- 
ticed page 237. From the Pliocene of Sinker Creek, Idaho. 

Mastodon obscurus. 

Leidy : Ext. Mam. N. America 1809, 390. For earlier synonymy, see the same 

work. Pr. Ac. Nat. Sc. 1870, 99; 1871, 199; 1S72, 142. 
Mastodon Shepardi. Leidy: Pr. Ac. Nat. Sc. 1870, 98; 1871, 199. 
Rhi/nchotheriuln ? See Falconer : Palteontological Memoirs, ISOS, II, 74. 



Originally named from remains found in Maryland, North Carolina, and 

Georgia. See Extinct Mamnialian Fauna of Dakota and Nebraska, 

1869, 244, 396. Remains from California and New Mexico described 

page 231 and represented in Figs. 1 to 4, Plate XXI and Figs. 1 to 4, 

Plate XXII, of the pres(?nt work, are supposed in whole or part to 

belong to the same species. If they do not, they would represent 

another species, which might retain the name of 31. Shepardi. 

In the. Palaeontographica for 1867, page 64, Von Meyer has given a 

description of the right ramus of the lower jaw of a Mastodon, from 

Mechoacan, Mexico. The specimen is represented in Plate VI of the 

same work, and it contains the last molar and llie one in advance, 

both entire. The portion of the last molar tooth in the jaw-fragment 



331 

iVoni New Jlexico, doscrilx'd page 235, and i('[)ix\seiitcd in Figs. 1, 4, 
Plate XXII, bears a veiy near resemblance vvitli the corresponding 
part of the same tooth in the Mechoacan specimen. Notwithstanding 
this likeness, it woidd appear that the fore part of the jaw differs so 
much that tlie two may l)e supposed not to pertain to the same species. 
As stated in the account of the New Mexico Mastodon, the anterior 
extremity of the jaw is enormously prolonged and provided with a pair 
of incisor's. Von Meyer observes of the Mechoacan specimen, "Too 
little of the symphysis is preserved to speak with any certainty of its 
constitution ; but it appears not to have contained incisors and rather 
ended in front in a short beak, as in the elephant." The jaw he I'efers 
with doubt to the Mastodon Humholdti. 

- I have said that -the New Mexican and Mechoacan specimens may be 
supposed not to pertain to the same species. However, when we con- 
sider the difference in the fore part of the lower jaw of the sexes in 
the Mastodon americanus, it is not improbable that the male of the 
Mastodon Shepardi may have had the lower jaw provided with a long 
beak and incisors which might have been absent in the female. 



'&" 



UINTATHERIUM. 

Titanotlierium. Marsli : Am. Jour. Sc. 1S71, II, 35 ; the article published in 
advance Juue 21, 1871 ; ibid. 1872, IV, 123, ijublished iu advance July 22, 
1872. 

Mastodon. Marsh: Am. Joui-. Sc. 1872, note to p. 123, published iu advance 
July 22, 1872. 



UlNTATHERIUM. 



Leidy: Pr. Ac. Nat. Sc. 1872, 1G9 ; in a letter addressed to the Academy and 
published in advance of the proceedings August 1, 1872. Reprinted in Am. 
Jour. Sc. September, 1872, 239. Pr. Ac. Nat. Sc. 1872, 241. Marsh: Pr. Am. 
Phil. Soc. 1872, 578; Am. Jour. Sc. 1873, V, 118; American Naturalist 
1873, 147. Cope: Pr. Ac. Nat. Sc. 1873, 10, 102; Pr. Am. Phil. Soc. Feb., 
1873. Nature : March 13, 1873, 3GG. 

Uititamastix. Leidy : Pr. Ac. Nat. Sc. 1872, 169. 

Tinoceras. Marsh: Am. Jour. Sc. 1872, IV, in errata of Sept. No.; do., p. 504, 
published in advance August 19, 1872; ibid. 1872, IV, 322, published in 
advance August 24, 1872 ; ibid. 1872, IV, 323. published iu advance Sep- 
tember 21, 1872; ibid. 1872, IV, 343, published in advance September 27, 
1872; ibid. 1873, V, 117, published in advance January 28, 1873; ibid. 1873, 
V, 293, published iu advance March' 18, 1873; American Naturalist Jan., 
1873, 52. 



Eohttsileus. Oojn' :* Pr. Am. riiil. Soc. 1872, 4.S5, pxiblisbed in advance August 
L'O, 1872; ibid. 1872, 512; ihiil. 1873, published as a separate pamphlet, "On 
the Short-Footed Ungulata of the Eocene of Wyoming," March 11, 1873 ; Pr. 
Ac. Nat. So. 1873, 10, 102 ; American Naturalist, March 1873, 180. 

LoxoJophodon. Cope : Pr. Am. Phil. Soc. 1872, 487, 488, published in advance 
August 22, 1872. Here regarded as the same genus tirst named in the Pro- 
ceedings of February 16, 1872, 420, and founded on the tooth of an animal 
about the size of the American tapir, referred to Bathmodon semicinctus and 
then to Loxolophodon. Pr. Am. Phil. Soc. 1872, 580 ; Pr. Ac. Nat. Sc. 1873, 
102. 

LcfalopUodon. Typograpliical error? Cope: Pr. Am. Phil. Soc. 1872, 515. 

IHnoccras. Marsh : Am. Jour. Sc. 1872, IV, 344, published in advance September 

27, 1872; iUd. 1873, V, 117-122, Plates I, II, published in advance January 

28, 1873 ; ibid. April, 1873, published in advance March 18, 1873 ; American 
Naturalist, March 1873, 146. Nature, March 13, 1873, 3GG. 

Loxolophodon. Cope: " Ou the Short-Footed Ungulata of the Eocene of 
Wyomiug," read before the Am. Phil. Soc, Feb. 21, 1873, and published in 
advance of the Proceedings, March 14, 1873. The name is here used as that 
of a genus recognized as distinct from the one originally described wuler tlie 
same name, which the author now regards as a synonym of Bathmodon. 

All the above names I suspect to have been applied to members of the 
same genus, and in this view have regarded them as synonyms to the 
first characteristic generic name employed. Of this, however, I am by 
no means positive, as I have had no opportunity of examining the 
difterent fossils upon which the genera were founded, except those 
described by myself under the name of Ulntatherium robustum, and the 
skull described by Professor Cope under the name of Loxolophodon cornutus. 

In addition, we have the description and figures of the skull described by 
Professor Marsh under the name of Dinoceras inirabilis. 

As far as I am al)lc to estimate the differences which have been indicated 
by the authors just named and those observed by myself, they appear to be 
rather of specific value, and perhaps in part of sexual character, than of 
generic importance. We hope, however, that all obscurity in relation to the 
matter will be cleared away when Professor Marsh and Professor Cope 
present to ns full descriptions with characteristic figures of the fossils in 
their possession. I may add it is not improbable that the names of 
Uintatherium, Tinoceras, Eobasileus, Dinoceras, and Loxolophodon, may be 

* The dates given as those of Professor Cope's publications in advance of the dif- 
ferent periodicals named are taken from the jiublications themselves; but they are, 
in some instances, contested by Professor Marsh. See an article read before the 
Philadelphia Academy of Sciences April 8, 1873, and published by Professor Marsh' 
under the title " On the Dates of Professor Cope's Recent Publications." 



c 



c.x|}ressivu of more llian one genus, in the light that Ciiriacus, Capreohis, 
Blastocerus, Axis, Elaphus, &c., are distinct from Cervus. Future compari- 
sons and discoveries will perhaps reduce the nine s|)ecies of the five genera 
wliich have been indicated to the number of two or three species of one or 
two genera. 

Professor Marsh has referred the remarkable animals above indicated to a 
new order with the name Dinocerata. In the uncertainty as to the true 
ordinal position of Uiutatherium, I have allowed it to remain, according to 
my tirst impression, with the Proboscidea. 

UlNTATHEEIUM ROBUSTUM. 

Leidy : Pr. Ac. Nat. Sc. 1872, 1G9, iu a letter addressed to the Academy and 
published in advance of the proceedings, August 1, 1872. Keprint ot the 
letter in Am. Jour. Sc. September, 1872, 239. Pr. Ac. Nat. Sc. 1872, 241. 
Cope: Pr. Ac. Nat. Sc. 1873, 102; Pr. Am. Phil. Soc. 1873. Marsh: Am. 
Jour. Sc. 1873, V, 290 ; American Naturalist, January, 1873'. 

Uintamastiv atrox. Leidy : Pr. Ac. Nat. Sc. 1872, 169 ; Am. Jour. Sc. 1872, 239. 

Binocems mirabUls. Marsh : Am. Jonr. Sc. 1872, IV, 344, published iu advance 
September 27, 1872; ibid. 1873, V, 117-123, Plates I, II, published in advance 
January 28, 1873; Ibid. April, 1873, published iu advance March IS, 1873. 
American Naturalist, March, 1873, 140. Nature, March 13, 1873, 300. 

Uintathcrium mirahile. Cope : Pr. Ac. Nat. Sc. 1873, 102 ; Pr. Am. Phil. Soc. 
1873, published iu advance " On the Short-Footed Ungulata of the Eocene of 
Wyoming, March 14, 1873, 28." 

The Figs. 6 to 12, Plate XXV, Figs. 1 to 3, Plate XXVI, and Figs. 30 to 34. 
Plate XXVII, of the present work, represent the chief type-specimens upon 
which the genus Uintatherium was founded and the species U. robustum 
named. Descriptions of these occur on pages 93 and 96. 

The large canine tooth represented in Figs. 1 to 5, Plate XXV, was, on 
discovery, supposed to belong to a Drepanodon-like carnivore. The dis- 
covery of the nearly complete skulls described by Professor Marsh under the 
name of Dlnoceras ?nirabilis, and Professor Cope under the name of Loxolo- 
yhodon cornutus, leaves no doubt that the remarkable tooth l)elongs to the 
same kind of an animal, which, from the proportions of the specimen, I sup- 
pose to be Uintatherium robustum. 

The tine skull discovered and described by Professor Cope under the name 
of Lo.rolophodon cornutus, I had the opportunity of seeing on the occasion 
when it was exhibited at a meeting of the Academy of Natural Sciences. 
So fiir as I could judge from the cursory examination, and from the more 



334 

recent description and figures of the skull, it appears to me to be a larger 
s2)eciesof Uintatherium than the U. rohustum, l)ut not of a distinct genus. 

The remains, which were first noticed by Professor Marsh and referred to 
Titanotherium (?) anceps, subsequently to Mastodon anceps, and finally to 
Tinoceras anceps, I have not seen. I have suspected that perhaps they 
might pertain to the same animal as that I have described as Uintatlierium 
rohustum. Should this prove to be the case, as the specific name of anceps 
is of earliest date, the latter woukl be correctly designated as Uintatherium 
anceps. 

Professor Marsh regards the Eohasileus s Loxolophodon cornutus, Cope, as 
pertaining to Tinoceras, probably T. grandis, Marsh, (Am. Jour. Sc. April, 
1873.) On the other hand Professor Cope refers Dinoceras to Uintatherium, 
and also includes as synonyms Titanotherium (?) anceps, and therefore Tinoceras, 
Marsh, (Pr. Am. Phil. Soc. 1873.) Thus the conjoint views of these authors 
rather favor the idea that all are probably of the same genus. 

Since the article on Uintatherium rohustuin, page 96, was printed, I have 
attempted a restoration of the skull in Fig. 1, Plate XXVIII, on an enlarged 
outline taken from Professor Marsh's Fig 1, Plate II, of Dinoceras mirahilis, 
published in the American Journal of Science for February, J 873. The 
ci'anial fragment and that of the upper jaw with the last molar tooth are 
taken from the same skull as the specimens of Fig. 8, Plate XXV, and 
Fig. 1, Plate XXVl. The canine is from the same specimen as Fig. 1, Plate 
XXV. 

In the May number of the American Journal of Science for 1873, Pro- 
fessor Marsh has indicated what he considers to be a new species of Dinoceras 
with the name of Z>. lucaris. In the account he observes, " From Uintatherium, 
so far as that genus is at present known, Dinoceras differs in the jJosition of 
the occipital condyles, in the more anterior position of the posterior horns, 
and. in the last molar, which lacks the external cone between the two trans- 
verse ridges, and has a second small tubercle behind the posterior ridge." 
These characters may, perhaps, together with others more important, point 
to a different species, but appear hardly sufficient to distinguish a genus. 
The differences are also more apparent than real ; for instance, the so-called 
"external cone between the two transverse ridges" of the last molar, as seen 
in Fig. 7, Plate XXV, is nothing more than a tubercle produced from the 
basal ridge, might be absent iu another individual, and is actually so in the 
molar in advance, as seen in Fig. 12 of the same Plate. 



335 

MEGACE^OPS* s. Megacemtops. 
Megacerops qoloradensis. 

Leidy : Pt. Ac. Nat. Sc. 1870, 1 ; Haydeu's Reii. Geol. Sur. Wyomiug, 1871, 352. 
Megaceratops color adoensis. Cope: Pr. Ac. Nat. Sc. 1873, 102; Pr. Am. Phil. 
Soe. 1873. 

Described page 239, and represented by Figs. 2, 3, Plate I, and Fig. 2, 
Plate II. 

Before the discovery of the more characteristic specimens of the skulls of 
species of Uiiitatheriuni, from the nearer resemblance of the fossil described 
under the name of Megacerops to the corresponding part of Sivatherium, 
the animal to vvliicli it belonged was supposed to be a ruminant. It now 
appears probable that Megacerops forms a member of the same order, what- 
ever that may l)e, with Uintatherium. 

Rodentia. 

SciURIDyE. 

PARAJHYS. 
Paramys delicatus. 

Leidy: Pr. Ac. Nat. Sc. 1871, 231; Ilaydeii's Kep. Geol. Sur. Montana, 1872, 
357. 

Described page 110, and represented hy Figs. 23 to 25, Plato VI. From 

the Bridger Eocene of Wyoming. 

Paramys delicatior. 

Leidy : Pr. Ac. Nat. Sc. 1871, 231 ; Haydeu's Rep. Geol. Sur. Montana, 1872, 357. 
Described page 110, and represented by Figs. 26, 27, Plate VI, and Figs. 
16 to 18, Plate XXVII. From the Bridger Eocene of Wyoming. 

Paramys delicatissimus. 

Leidy: Pr. Ac. Nat. Sc. 1871, 231 ; Hayden'sEep. Geol. Sur. Montana, 1872,357. 
Described page 111, and represented by Figs. 28, 29, Plate VI. From 
the Bridger Eocene of Wyoming. 

SCIUPtAVUS ! 

Marsli : Am. Jour. Sc. 1871, 122. 
A tooth supposed to pertain to this genus is described on page 113, and 
represented in Fig. 30, Plate VI. From the Bridger Eocene of Wyo- 



* For the sake of l)oth brevity and euphony, I have preferred to use Jlegaccrops 
instead of Megaeeratoiis, ju.st as Megatherium is preferred toMegalolheriiun, &c. 



336 

MuEIDiE. (?) 

MYSOPS. 

Mysops minimus. 

Leidy: Pr. Ac. Nat. Sc. 1871, 232; Hayden's Eep. Gcol. Sur. Moutaua, 1872, 
357. 
Described page 111, and represented bj Figs. 31, 32, Plate VI. From the 
Bridger Eocene of AVyoming. 
Mysops fkaternus. 

Described page 112, and represented by Figs. 14, 15, Plate XXVII. 
From the Bridger Eocene of Wyoming. 

Insectivora. 

FAMILIES UNDETEKMINED. 
OMOMYS. 

Omomys carteri. 

Leidy: Pr. Ac. Nat. Sc. 18G9, G3. 
Originally described in the Extinct Mammalia of Nortli America, 1S69, 
408, and represented in Figs. 13, 14, Plate XXIX of the same work. 
Redescribed in the present work, 120. From the Bridger Eocene of 
Wyoming. 

PAL^ACODON. 

PALiEACODON VERUS. 

Leidy : Pr. .Ac Nat. Sc. 1872, 21 ; Hayden's Eep. Geol. Sur. Montana, 1872, 356. 
Described from specimens of teeth page 122, and represented by Fig. 46, 
Plate VI. From the Bridger Eocene of Wyoming. 

WASHAKIUS. 

Washakius insignis. 

Described page 123 from a small jaw-fragment containing the last two 
molars, and represented in Figs. 3, 4, Plate XXVII. From the Bridger 
Eocene of Wyoming. 

Sirenia. 
MANATUS. 

Makatlis inoknatus. 

Figs. 16, 17, Plate XXXVII, represent the crown of a tooth from the 
" phosphate l>eds'' of the Ashley River, South Carolina. It most nearly 



337 



resembles the corresponding part of the lower teetli of the living Manatee of 
the Florida coast, and it indicates an animal of about the same size. Tlie 
constituent lobes of the crown are less contracted approaching the summits, 
and the intervening valleys are wider than in the teeth of the living Manatee. 
The summits of the lobes being less contracted, are also sliarper and not so 
wrinkled. The summit of the anterior lobe presents a wider and deeper 
oval pit, and the posterior heel is less mammillary, not wrinkled at the sum- 
mit, and is broadly sloping at its fore part. The crown measures half an inch 
four and aft and 4J lines where widest. 

Zeuglodontia. 

PONTOBASILEUS. 

PONTOBASILEUS TUBERCULATUS. 

Fig. 15, Plate XXXVII, represents a fragment of a remarkable tooth, 
apparently belonging to an animal of the same order as the Basilosaurus. 
The specimen pertains to the Museum of the Academy of Natural Sciences 
of Philadelphia. It is without label, and was associated with some Basilosaurus 
remains from Alabama. I suppose it to have been derived from some Eocene 
or Miocene formation of the Atlantic States. Upon the fang there are the 
remains of two white disks, apparently the basal attachment of barnacles. 

The fragment consists of the back portion of the crown and the corre- 
sponding fang of a double-fanged tooth. The crown has been very unlike 
that of any known animal of the order. The conical summit occupied a 
position over the separation of the fangs, including at most the anterior one. 
The back part of the crown forms a wide, thick heel, extending over more 
than half the width of the corresponding faug. The enamel is exceedingly 
tuberculate, and near the most prominent portion of the heel outwardly it is 
worn off over a small oval space from attrition of an opposed tooth. The 
fang is widely divergent, and is depressed along the middle externally and 
internally, and also more deeply on the surface opposed to the absent fang. 

Cetncea. 
Delphinid^. 

GRAPHIODON. 
Graphiodon vinearius. 

Leidy : Pr. Ac. Nat. So. 1870, 122. 
An extinct genus and species ol' cetacean animals, apparently dilFerent 
43 o 




338 

from any previously described, is indicated by a fossil submitted to my 
examination l^y the Smithsonian Institution. The specimen was found by 
Mr. Pearce in the Miocene formation of Gay Head, Martha's Vineyard. It 
consists of a tooth represented in Fig. 7, Plate XXII, of the natural size. 

The form of the tooth, with its huge gibbous fang, led me at first to mis- 
take it for that of a mosasauroid reptile, nor did I observe my error until it 
was suggested by Professor Marsh 

The crown of the tooth is curved, conical, and without subdivisional planes 
upon the surface. The inner and outer surfaces are barely defined i^ostero- 
internally by a feeble and interrupted ridge. The enamel is singularly 
wi-iukled, the wrinkles being short, vermicular, somewhat branched and 
crowded, and they remind one of Arabic letters. At the base of the crown 
the enamel is nearly smooth. The transverse section of the crown is cir- 
cular, and measures 8 lines in diameter. The length of the crown when 
complete appears to have been about twice the latter. 

The fang of the tooth, broken at the extremity, exposes to view a large 
interior pulp cavity. It is longer than the crown and very gibbous. In its 
relation of size and form, it is wonderfully like the corresponding part in the 
teeth of Mosasaurus. It is ovoidal in tbrm and is curved in the dii'ection of 
the crown. It is abruptly thickened at the base of the latter, and on one 
side, near-the extremity, exhibits a deep groove. The texture of the fang, as 
seen at its broken part, appears as dense as ordinary dentine. In the entire 
condition, the fang has approximated 2 inches in length ; its diameter is 
about half the length. 

REP T ILIA. 

Dinosauria. 

POICILOPLEURON. 

Deslongchamps : Mem. Soc. Liu. de Normandie VI, 1838, 37. 

POICILOPLEURON VALENS. 

Leidy : Pr. Ac. Nat. Sc. 1870, 3. 
Antrodemus. Leidy : Ibidem, 4. 

Founded on several fragments of vertebree described page 267, and rep- 
resented by Figs. 16 to 18, Plate XV, under the name of Antrodemus. 
From Colorado, and supposed to have been derived from the Cretaceous 
formation. 



339 
Chelonia. 

TESTUDINIDiE. 

TESTUDO. 

Testudo Coesoni. 

Leidy: Pr. Ac. Nat. Sc. 1871,154; 1872,268; Hayden's Eep. Geol. Siir. Mon- 
tana, 1872, 3GG. 

Emys Carteri. Leidy: Pr. Ac. Nat. Sc. 1871, 228; Hayden's Eep. Geol. Sur. 
Montana, 1872, 3G7. 

Described page 132, and represented in Figs. 1, 2, Plate XT, under the 
name of Emys Carteri ; in Fig. 7, Plate XV ; Figs. 2 to 4. Plate XXIX, 
and Figs. 1 to 4, Plate XXX. From the Bridger Eocene of Wyoming. 

Testudo nebrascensis. 

Leidy : Pr. Ac. Nat. Sc. 1852, 59 ; Owen's Eep. Geol. Sur. Wisconsin, &c. 1852, 

567 ; Ancient Fauna of Nebraska, 1853, 103, Plate XIX ; Ext. Mam. Fauna 

of Dakota and Nebraska, 1869, 20. 
Stylemys nebrascensis. Leidy : Pr. Ac. Nat. Sc. 1851, 172 ; Ancient Fauna of 

Nebraska, 1853, 103 ; Ext. Mara. Fauna of Dakota and Nebraska, 1869, 26. 

See page 223. Cope: Ext. Batracbia, &c. 1870, 121. 
Emys s. Testudo hemisjiherica, Owciti, Ciilbertsoni, et lata. Leidy: Pr. Ac. Nat. Sc. 

1851, 173, 327 ; 1852, 34, 59. Owen's Eep. Geol. Sur. Wisconsin, &c. 1852, 

568 to 572; Ancient Fauna of Nebraska, 1853, 105 to 110, Plates XX to 

XXIV. 
Stylemys Gulbertsonii. Cope : Ext. Batracbia, &c. 1870, 124. 

Noticed page 224 under the name of SUjlemys nebrascensis, ;iud further 
represented by Figs. 7, 9, 10, Plate XIX. 

All the turtle i-emains from the Mauvaises Terres of White River, Dakota, 
which have come under my inspection, and which have been described under 
the various names above indicated, I regard as having pertained to a single 
species. This agrees so closely in the usual characters of living species of the 
land tortoises, that I have placed it in the same genus, though it is subgeneri- 
cally distinct. A mature and nearly perfect specimen of the shell in the 
Museum of the Academy of Natural Sciences, obtained by Professor Hayden 
in 1866, has the following dimensions : 

laches. 

Length of carapace in the curve : 27 

Breadth of carai)ace in the curve 26 

Length of plastron 20 

Breadth of plastrou 15 

Height of shell above the level 8 



340 

Testudo niobraeensis. 

Testiulo (Stylcmys) niohrarensis. Leidy : Pr. Ac. Nat. Sc. 185S, 29 ; Ext. Main. 

Fauua Dakota and Nebraska, 1SG9, 20. See page 224. 
Stylemys niohrarensis. Cope : Ext. Batracliia, &e. 1870, 124. 

Described page 225, under the name of Slylemys niohrarensis, and repre- 
sented by Figs. 4 to (5, Plate III, and Figs, fi, 8, Plate XIX. * From the 
Pliocene of the Niobrara River. 

Testudo okegonensis. 

Stylemys oregonensis. Leidy : Pr. Ac. Nat. Sc. 1871, 248. See page 225. 
Noticed page 226, under the name of Stylemys oregonensis, and repre- 
sented by Fig. 10, Plate XV. From the Mioceiie of Oregon. I suspect 
I have been too hasty in regarding this as a species distinct from Testudo 
nebrascensis. 

Emydidte. 

EMYS. 

Emys wyomingensis. 

Leidy : Pr. Ac. Nat. Sc. 18G9, G6 ; Haydeii's Kep. Geol. Sur. Montana, 1872, 367. 
Emys Sfcvensonkmus. Leidy : Pr. Ac. Nat. Sc. 1870, 5 ; Hayden's Eep. Geol. 
Sur. Wyoming, 1871 , 3GG. 

Umys Jeanesi. Leidy : Pr. Ac. Nat. Sc. 1870, 123 ; Haydeu's Eep. Geol. Sur. 

Wyoming, 1871, 3GC. 
Umys Haydeni. Leidy : Pr. Ac. Nat. Sc. 1870, 123 ; Hayden's Eep. Geol. Sur. 

Wyoming, 1871, 3GG. 

The species described page 140, and represented by Figs. 2 to 6, Plate 
IX, Figs. 1, 2, Plate X. From the Bridger Eocene of Wyoming. 

Emys peteolei. 

Leidy : Pr. Ac. Nat. Sc. 18GS, 17G. Cope : Ext. Batraebia, &c. 1870, 128. 
Species described page 260, and represented by Fig. 7, Plate IX. From 
the Quaternary of Texas. 

IIYBEMYS. 

IIyijemys aeenakius. 

Leidy: Pr. Ac. Nat. Sc. 1871, 103. 
Noticed page 174, and represented by Fig. 9, Plate XV. From the 
Bridger P^ocene of Wyoming. 



341 

FAMILIES UNDETERMINED, APPARENTLY INTERMEDIATE TO THE PLEURODIRIDiE 

AND THE CHELYDRID/E, 

BAPTEMYS. 

Baptemys wyomingensis 

Leicly : Pr. Ac. Nat. Sc. 1870, 4 ; Haydeu's Ecp. Geol. Siir. Wyomiilg, 1S71, 367 ; 

Haydeu's Rep. Geol. Sur. Montaua, 1872, 307. 
Adocus injoiniDffeniih. Cope: Pr. Am. Piiil. Soc. 1870, 297; Ext. Batracliia, 

Eeptilia N. Am. in Trau.s. Am. Phil. Soc. 1870, 233. 

Described page 157, and represented by Figs. 1, 2, Plate XII, and Fig. 6, 
Plate XV. From the Bridger Eocene of Wyoming. 

CHISTERNON s. Chisternu?n. 

Leidy : Pr. Ac. Nat. Sc. 1872, 102. 

ChISTERNON UNDATL'M. 

Baena undata. Leidy : Pr. Ac. Nat. Sc. 1871, 228 ; Haydeu's Rep. Geol. Sur. 
Montana, 1871, 3G9. 

Described page 169, and represented by Figs. 1, 2, Plate XIV, under tlie 

name of Baena undata. From the Bridger Eocene of- Wyoming. 

Chisternon undatum, in the presence of an additional pair of plates to the 

plastron, resembles the existing SternotliEerns. 

BAENA. 
Baena arenosa. 

Leidy : Pr. Ac. Nat. Sc. 1870, 123 ; 1871, 228 ; Hayden'.s Rep. Geol. Snr. Wyo- 
ming, 1871, 307 ; Haydeu's Rep. Geol. Sur. Montana, 1872, 308. 
Baena affinis. Leidy : Haydeu's Rep. Geol. Sur. Wyoming, 1871, 307. 

Species described page 161, and i-epresented by Figs. 1 to 3, Plate XIII, 

under the names of Baena arenosa and Baena affinis, Figs. 1 to 5, Plate 

. XV, and Figs. 8, 9, Plate XVI. 

ANOSTEIRA. 

Anosteira ornata. 

Leidy : Pr. Ac. Nat. Sc. 1871, 102, 114 ; Haydeu's Rep. Geol. Sur. Wyoming, 1872, 
370. 

Described page 174, and represented by Figs. 1 to 6, Plate XVI. From 

the Bridger Eocene of AVyoniing. 

Trionychid^. 

TRIONYX. 

Trionyx guttatus. 

Leidy : Pr. Ac. Nat. Sc. 18G9, 00 ; 1870, 5 ; 1871, 228 ; Haydeu's Rep. Geol. Sur. 
Wyoming, 1871, 367; Haydeu's Rep. Geol. Sar. Montana, 1872, 370. Cope: 
Ext. Batracliia, &c., 1870, 152. 



'342 

Desci-ibed page 176, and represented by Fig. 1, Plate IX. From the 
Bridger Eocene of Wyoming. 

Trionyx uintaensis. 

Leidy : Pr. Ac. Nat. Sc. 1872, 267. 
Described page 178, and represented by Fig. 1, Plate XXIX. From the 
Bridger Eocene of Wyoming. 

Teionyx ? 

Fragments descriljed page 180, and represented in Figs. 11, 12, Plate 
XVI. From the Bridger Eocene of Wyoming. 

SPHAEGIDIDiE 1 

ATLANTOCHELYS, 

Atlantochelys mortoni.* 

Agassiz : Pr. Ac. Nat. Sc. 1849, 169. 

Momsaurus Mitchelli. Leidy: Cret. Eept. in Siuitli. Coiitrib. 1865, 43, 116. De- 

termiuation admitted by Cope: Pr. Bost. Soc. Nat. Hist. 1869, 253. 
Protostega neptunia. Cope ; Pr. Am. Phil. Soc. 1872, 433. 

Fonnded on the fragment of a large humerus described in the " Cretaceous 
Reptiles of the United States," 1865, 43, and represented in Figs. 3, 4, 
5, Plate VIII of that work. From the Cretaceous green sand of New 
Jersey. See page 270. 

Atlantochelys tuberosus. 

Holcodus acutidess. lu part of Leidy : Cret. Eept. iu Smiths. Contrib. 18C5, 42, 

118. Determination admitted by Cope : Pr. Bost. Soc. Nat. Hist. 1869, 253. 

Platecarpus tympaniticus. In part of Cope : Pr. Bost. Nat. Hist. Soc. 1869, 265 ; 

Syuop. Est. Batrachia, Reptilia, &c. 1870, 199. 
Protostega. Cope: Pr. Am. Phil. Soc. 1872, 433. 
Platecarpus tuberosus. Cope: Pr. Am. Phil. 1872, 433. 
Protostega. tuberosa. Cope : Hayden's Eep. Geol. Sur. Montana, 1872, 330, 334. 

Founded on a humerus described in the "Cretaceous Reptiles of the 
United States," 1865, 42, and represented in Figs. 1, 2, Plate VIII of 
that work. From the Cretaceous formation near Columbus, Mississippi. 
See page 270. 

It was the association of this specimen with several cervical vertebras, and 

* Professor Cope observes that "this name was unaccompanied with the necessary 
description, and is hence useless to science." (Pr. Am. Phil. Soc. 1872, 433.) As the 
specimen on which it was founded was described and figures in my paper on the Cre- 
taceous Eeptiles, so as to be recognized by every student, I have preferred to employ 
the original name instead of the proposed substitute. 



343 

a palatine bone with teeth of an nndoubted niosasaiiroid, that led me'^into the 
error of snpposing it belonged to the same animal. This suggested the idea 
that the specimen originally referred to Atlantochelys Mortoni likewise be- 
longed to a Mosasauriis. The error was easy at a time when the limb-bones 
of none of the mosasanroids were known, ;uul when it was even doubted 
whether these rejjtiles possessed hinder lind)s. My determination was con- 
curred in, not only by Professor Cope, but also Ijy Prcdessor Agassiz, after I 
had exhibited to him the different specimens and their associates.* It was 
only after I had had the opportunity of seeing the nearly complete fore-limbs 
in the skeleton of Clidastes pro]iijthon, described by Professor Cope, that 
I suspected my reference of the specimens of humeri above indicated was 
incorrect. 

CYNOCERCUS? 

Cynocercus incisus. ■? 

Cope : Pr. Am. Phil. Soc. 1872, 309. 

Remains probably belonging to this species described page 2G9, and 
represented by Figs. 17 to 21, Plate XXXVI. From the Cretaceous 
of Kansas. 

Mosasauria. 
MOSASAURUS ? 

MOSASAURUS % 

See page 279. Represented by Fig. 15, Plate XXXVI. From the Cre- 
taceous of Nebraska. 

TYLOSAURUS. 

Tylosaurus dyspelor. 

Marsh : Am. Jour. So. 1872, 147. 

Liodon dyspelor. Cope : Pr. Am. Phil. Soc. 1870, 572, 574 ; 1871, 109, 280 ; Hay- 
den's Eep. Geol. Sur. Wyoming, 1871, 410 ; Haydeii's Rep. Gcol. Snr. Montana, 
1872, 333. 

Rhinosaurus dyspelor. Mar.sh : Am. Jour. So. 1872. 

BUampliosaurus. Cope : Pr. Ac. iSTat. Sc. 1872, 141. 

See page 271. Represented by Figs. 1 to 11, Plate XXXV. From the 
Cretaceous of New Mexico and Kansas. 

* I do not introduce the names of these naturalists as an apology for my error, but 
rather to show that able authorities are liable to the same mistaices under tlie same 
circumstances. 



344 

Tylosaurus peoriger. 

Marsh : Am. Jour. Sc. 1872, 147. 

Macrosaurus j)roriger. Cope: Pr. Ac. Nat. Sc. 1869, 123. 

Liodon proriger. Cope: Trans. Am. Phil. Soc. 1870, 202; 1871, 279; Haydeu's 

Eep. Geol. Sur. Wyoming, 1871, 401 ; Hayden's Eep. Geol. Sur. Montana, 1872, 

333. 
Ehinosaitriis jiroriger. Marsh: Am. Jour. Sc. 1872. 
Ehampliosaurus. Cope : Pr. Ac. Nat. Sc. 1872, 141. 

See page 274. Represented l)y Figs. 12, 13, Plate XXXV, and Figs. 1 to 

m the Cretaceous oi 

LESTOSAURUS. 



3, Plate XXXVI. From the Cretaceous of Kansas. 



Lestosaurus coryph^us. 

Maish : Am. Jour. Sc. 1872. 

Holcodus corypliicus. Cope : Pr. Am. Phil. Soc. 1871, 269 ; Hayden's Rep. Geol. 

Sur. Montana, 1872, 331 . 
f Platecarpns. Cope: Pr. Ac. Nat. Sc. 1872, 141. 

See page 276. Represented by Figs. 12 to 14, Plate XXXIV, and Figs. 
4 to 14, Plate XXXVI. From the Cretaceous of Kansas. 

CLIDASTES. 

Cope : Pr. Ac. Nat. Sc. 1868, 2.33. 

Clidastes intermedius. 

Leidy : Pr. Ac. Nat. Sc. 1870, 4. Cope : Syu. Ext. Batrachia, Reptilia, &c. 
1870, 221 ; Hayden's Rep. Geol. Sur. Wyoming, 1871, 412. 

Described page 281, and represented by Figs. 1 to 5, Plate XXXIV. From 
the Upper Cretaceous of Alabama. 

Clidastes affinis. 

G. intermedius. lu part, Leidy : Pr. Ac. Nat. Sc. 1870, 4. 

Described page 283, and represented by Figs. 6 to 11, Plate XXXIV. 
From the Cretaceous of Smoky Hill River, Kansas. 

Lacertilia.- 

SANIWA s. Saniva. 

Saniwa ensidens. 

Leidy : Pr. Ac. Nat. Sc. 1870, 124 ; Hayden's Rep. Geol. Sur. Wyoming, 1871, 
368 ; Haydeu's Rep. Geol. Sur. Montana, 1872, 370. 

Described page 181, and represented by Fig. 15, Plate XV, and Fig_ 3.5, 
Plate XXVII. From the Bridger Eocene of Wyoming. 



Saniwa major. 

Described page 182, and represented by Fig. 14, Plate XV, Figs. 36, 37, 
Plate XXVII. From the Bridger Eocene of Wyoming. 

CHAMELEO. 

ClIAMELEO PRISTINUS, 

Leidy : Pr. Ac. Nat. Sc. 1872, 277. 

Described page 184, and represented by Figs. 38, 39, Plate XXVII. 
From the Bridger Eocene of Wyoming 

G-LYPTOSAURUS. 

Marsh : Am. Jour. Sc. 1871 ; Pr. Ac. Nat. Sc. 1871, 105. 

Glyptosaurus 1 

Noticed page 182, and represented by Fig. 13 to 17, Plate XVI. From 
the Bridger Eocene of Wyoming. 

TYLOSTEUS. 

Tylosteus ornatus. 

Leidy: Pr. Ac. Nat. Sc. 1872, 40. 

Noticed page 285, and represented by Figs. 14, Plate XIX. From the 
Upper Missouri ; probably Cretaceous. 

Sauropteri/gia. 
NOTHOSAURUS. 

NOTHOSAURUS OCCIDUUS. 

Nothosaurops occiduus. LeiOy : Pr. Ac. Nat. Sc. 1870, 74. 

Noticed page 287, and represented by Figs. 1 1 to 13, Plate XV. From 
the Cretaceous 1 of Moreau River, Dakota. 

OLIGOSIMUS. 

■OlIGOSIMUS GRANDiEVUS. 

Leidy : Pr. Ac. Nat. Sc. 1872, 39. 

Described page 286, and represented hy Figs. 18, 19, Plate XVI. From 
the Cretaceous (?) of Wyoming. 
44 G 



FISHES. 

Teleostei. 

Labrid^. 

PROTAUTOGA. 
Protautoga conidens. 

Tautoga (Protautoga) conidens. Leidy : Pr. Ac. Nat. Sc. 187.3, 15 ; Am. Jour. Sc. 
1873, 312. 

A short time since, Mr. C M. Smith, engineer, of Richmond, Virginia, 
submitted to the writer, for examination, a small collection of fossil bones, 
which had been discovered by him during the construction of a tunnel 
beneath the city. Mr. Smith informs me that the material penetrated by 
the tunnel, in which the bones were found, consists of a stiff blue clay con- 
taining remains of infusoria. Oh examining a portion of the substance with 
the microscope, I observed an abundance of well-preserved frustules of 
Coscinodiscus, besides many other less conspicuous diatomes. 

The fossil bones consist mainly of vertebrae and teeth of Cetaceans, the 
teeth of Procamelus virginietisis, previously described, a portion of a humerus 
of a bird, and a number of remains of fishes. 

Among the latter there are two specimens which consist of portions of 
the premaxillaries, with teeth, represented in Figs. 56, 57, Plate XXXII, of 
a species of Tautoga larger than the living black-fish, Tautoga americana. 

The better-preserved specimen exhibits the base of attachment of the 
first large tooth, and succeeding it a row of seven teeth. These are separated 
by wider intervals than the fewer teeth of the same kind of the recent black- 
fish. The points of the teeth are more regularly conical tlian in the latter. 
Within the position of the larger teeth there is a row of small teeth. 

The second specimen contains the first large tooth alone. This tooth is 
not longer than in the recent bl^ck-fish, but is more robust, and its enameloid- 
covered extremity is more perfectly conical or is less flattened from without 
inwardly. 

The premaxillary bone is flatter externally than in the black-fish, and looks 
as if it had not turned down in a hook-like end as in the latter. The speci- 



347 

mens I have supposed to indicate a genus closely related with Tautoga, and 
have named it Protautoga. 

The more complete specimen contained a row of eight teeth in a space of 
an inch and a quarter from the symphysis. The first large tooth is 5J lines 
long: the crown-like portion is 3J lines long, witli the breadth at base 2i 
lines. The second tooth is 4.4 lines long; the crown-like portion is 2 lines 
long and 1.6 lines in diameter at base. The other teeth range from 2 lines 
to a line in length. 

SPHYEiENID^. 

ENCHODUS. 

Enchodus Shumarui. 

Leidy : Pr. Ac. ^^at. Sc. 1856, 257. 
Described page 289, and represented by Fig. 20, Plate XVII. From the 
Cretaceous of Sage Creek, Dakota. 

PHASGANODUS. 

Phasganodus oirus. 

Leidy : Pr. Ac. Nat. Sc. 1857, 107. 
Described, page 289, and represented by Figs. 23, 24, Plate XVII. From 
the Cretaceous of Cannon Ball River, Dakota. 

CLADOCYCLUS. ? 

ClaDOCYCLUS 1 OCCIDENTALIS. 

Leidy : Pr. Ac. Nat. Sc. 1856, 256. 
Noticed page 288, and represented by Figs. 21, 22, Plate XVII, and Fig. 
5, Plate XXX. From the Cretaceous of Sage Creek, Dakota. 

Clupeid^. 

CLUPEA. 

ClUPEA HUMILIS. 

Leidy : Pr. Ac. Nat. Sc. 1856, 256. 
Page 195, and represented by Fig. 1, Plate XVII. From the Eocene 
shales of Green River, Wyoming. 

Clupea alta. 

Described page 196, and represented by Fig. 2, Plate XVII. From the 
Eocene shales of Green River, Wyoming. 



348 

CyPRINIDyE. 

MYLOCYPRINUS. 

Mylocyprinus robustus. 

Leidy : Pr. Ac. Nat. Sc. 1870, 70. 
Described page 262, and represented by Figs. 11 to 17, Plate XVII. 
From the Pliocene of Idaho. 

SlLURID^. 

PIMELODUS. 

PiMELODUS ANTIQUUS. 

Leidy : Pr. Ac. Xat. Sc. 1873, 99. 
Page 193, and represented by Figs. 44 to 46, Plate XXXII. From the 
Tertiary of Big Sandy and Green Rivers, Wyoming. 

FAMILY UNDETERMINED. 

XiPIIACTINUS. 
XiPHACTINUS AUDAX. 

■ Leidy: Pr. Ac. Nat. Sc. 1870, 12. 
Described page 290, and represented by Figs. 9, 10, Plate XVII. From 
the Cretaceous of Smoky Hill River, Kansas, and L'eau qui Court 
County, Nebraska. 

GANOIDEI. 

Cydoganoidei. 

AMIA. 

Amia uintaensis. 

Amia fProtamiaJ uintaensis. Leidy : Pr. Ac. Nat. Sc. 1873, 98, 
Page 185, and represented by Figs. 1 to 6, Plate XXXII. From the 
Bridger Eocene of Wyoming. 
Amia media. 

Amia fProtamiaJ media. Leidy : Pr. Ac. Nat. Sc. 1873, 98. 
Page 188, and represented by Figs. 7 to 11, Plate XXXII. From the 
Bridger Eocene of Wyoming. 

Amia gracilis. 

Amia fProtamiaJ gracilis. Leidy : Pr. Ac. Nat. Sc. 1873, 98. 
Page 188, and represented by Figs. 23, 24, Plate XXXII. From the 
Bridger Eocene of Wyoming. 



349 

HYPAMIA. 

Hypamia elegans. 

Leidy : Pr. Ac. Nat. Sc. 1873, 98. 
Page 189, aud represented by Figs. 19 to 22, Plate XXXII. From the 
Bridger Eocene of Wyoming. 

FAMILY UNDETERMINED. 

PIIAREODUS. 
Phaeeodus acutus. 

Leidy : Pr. Ac. Nat. Sc. 1873, 99. 
Page 193, and represented by Figs. 47 to 51, Plate 193. From the 
Bridger Eocene of Wyoming. 

Rliomhoganoidei. 

LEPipOSTEUS. 
Lepidosteus atrox. 

Leidy': Pr. Ac. Nat. Sc. 1873, 97. 
Page 189, and represented by Figs. 14, 15, Plate XXXII. From tlie 
Bridger Eocene of Wyoming. 

Lepidosteus ? 

Leidy : Pr. Ac. Nat. Sc. 1873, 98. 
Page 190, and represented by Figs. 16, 17, 25, 27 to 30, Plate XXXII. 
From the Bridger Eocene of Wyoming. 

Lepidosteus simplex. 

Leidy : Pr. Ac. Nat. Sc. 1873, 98. 
Page 191, and represented by Figs. 18, 26, 31 to 43, Plate XXXIL 
From the Bridger Eocene of Wyoming. 

Lepidosteus notabilis. 

Leidy : Pr. Ac. Nat. Sc. 1873, 98. 
Page 192, and represented by Figs. 12, 13, Plate XXXII. From the 
Bridger Eocene of Wyoming. 

PYCNODUS. 

Pyc'nodus faba. 

Leidy : Pr. Ac. Nat. Sc. 1872, 163. 
Described page 292, and represented by Figs. 15, 16 Plate XIX. From 
the Cretaceous of Mississip|)i and New Jersey. 



350 

Pycnodus robustus. 

Leitly : Pr. Ac. Nat. Sc. 1857, 168. 
Noticed page 293, and represented by Figs. 18, 19, Plate XXXVII. From 
the Cretaceous of New Jersey. 
Pycnodus cauolinensis. 

Emmous: North Oaroliua Geol. Sur. 1858, 211, Fig. 96. 
Noticed page 294. From the Miocene of North Carolina. 

HADRODl^S. 

Hadijodus priscus. 

Leitly : Tr. Ac. Nat. Sc. 1857, 167. 
Described page 294, and I'epresented by Figs. 17 to 20, Plate XIX. From 
the Cretaceous of Mississippi. Specimen discovered by Dr. William 
Spillman. 
Since the determination of the reptilian character of the genus Placodus, 
I have suspected that this one may also belong to the same order. 

Placoganoidei. 

ACIPENSER. 

AciPENSER ORNATUS. 

Leid y : Pr. Ac. Nat. Sc. 1873, 15 ; Am. Jour. Sc. 1873, 312. 
Among the fossils in Mr. C. M. Smith's collection from the Miocene forma- 
tion of Virginia, previously mentioned, there is a dermal plate of a stur- 
geon, especially interesting on account of tlic rarity of the remains of 
fishes of the same family. 
The specimen is represented of the natural size in Fig. 58, Plate XXXII, 
and is nearly entire. It appears to have been one of the lateral plates, and 
indicates a species about the size of our common sturgeon of the Delaware 
River. Though exhibiting no positive distinctive character, it most probably 
pertained to a species now extinct. 

ELASMOBRANCHI. 

Holocepliali. 

EDAPHODONTIDiE. 

EDAPHODON. 

Edaphodon mirificus. 

Leidy : Pr. Ac. Nat. Sc. 1856, 221. 
Described page 306, and represented by Figs. 6 to 12, Plate XXXVII. 
From the Cretaceous of New Jersey. 



351 
EUMYLODUS. 

EUMYLODUS LAQUEATUS. 

Described page 309, and represented by Figs. 21, 22, Plate XIX, and Figs. 
13, 14, Plate XXXVII. From the Cretaceous of Mississippi. 

Plagiostomi. 

Squalid^. 

LAMNA. 
Lamna ? 



Described page 304, and represented by Figs. 44, 45, Plate XVIII. From 
the Cretaceous of" Kansas and the Chalk of England. 

Lamna \ 



Described page 304, and represented by Figs. 46 to 50, Plate XVIII. 
From the Cretaceous of New Jersey, Mississippi, and Kansas. 

OTODUS. 
Otodus divaricatus. 

Leidy : Pr. Ac. Nat. Sc. 1872, 1G2. 

Described page 305, and represented l)y Figs. 26 to 28, Plate XVIII. 
From the Cretaceous of Mississippi. 

OXYRHINA. 

OXYEHINA EXTENTA. - - 

Leidy : Pr. Ac. Nat. Sc. 1872, 1G2. 

Described page 302, and i-epresented by Figs. 21 to 25, Plate XVIII. 
From the Cretaceous of Kansas and Mississippi. 

GALEOCERDO. 

Galeocerdo falcatus. 

Described page 301, and represented by Figs. 29 to 43, Plate XVIII. 
From the Cretaceous of Kansas, Mississippi, Texas, and England. 

Hybodontid^. 

CLADODUS. 

Cladodus occidentalis. 

Leidy : Pr. Ac. Nat. Sc. 1859, 3. 

Cladodus mortifer. Newberry aud Wortben : Geo]. Sur. Illinois, vol. ii, Pake- 

outology 22, Plate I, Fig. 5. St. Jobu: Haydeu's Rep. Geol. Sur. Nebraska, 

1872, 239, Plate IH, Fig. 6; Plate VI, Fig. 13. 



Described paifc 311, and represented .l)y Figs. 4 to 6, Plate XVII. From 
the Carboniferous formation of Kansas, Nebraska, and Illinois. 

CESTRACIONTIDiE. 

ACRODUS. 

ACKODUS HUMILIS. 

Leidy : Pr. Ac. Nat. Sc. 1S72, 103. 
Described page 300, and re|irescntc(l by Fig. 5, Plate XXXVII. From 
the Cretaceous limestone of New Jersey. 

AcEODUS Emmonsi. 

Leidy : Pr. xVc. Nat. Sc. 1S72, 103. 

Acroclus. Emmous: North Carolina Geol. Sur. 18.58, 211, Fig. 97. 

Attributed by Professor Emmons to the Miocene of North Carolina. 

PTYCHODUS. 
Ptyohodus Mortoni. 

Agas.siz: PoIssods Fossiles III, 1833-'43, 158, Tab. 25, Figs. 1 to 3; copied in 
Figs. 773, 773rt, of Dana's Manual of Geology. Leidy : Pr. Ac. Nat. Sc. 1808, 
205. 

Palate-boiie of a fish ? Morton : Syn. Org. Rem. Cret. Group, 1831, Plate XVIII, 
Figs. 1, 2. 

Described page 295, and represented by Figs. 1 to 14, Plate XVIII 
From the Cretaceous of Kansas, Mississippi, and Alabama. 

Ptychodus occidentalis. 

Leidy : Pr. Ac. Nat. Sc. 1868, 207. 
Described page 298, and represented by Figs. 7, 8, Plate XVII, and Figs. 
15 to 18, Plate XVIII. From the Cretaceous of Kansas. 

Ptychodus Whippleyi. 

Marcou : Geology North America, 1858, 33, Plate I, Fig. 4. 
Described page 300, and represented by Figs. 19, 20, Plate XVIII. 
From tlie Cretaceous of Texas. 

Ptychodus polygykus. 

Agassiz : Poissous Fossiles III, 1833-'43, 150. Dixon : Geol. Sussex, 1850, 363. 
Gibbes: Jour. Ac. Nat. Sc. 1810, 290, Plate XLII, Figs. 5, 0. Leidy: Pr. Ac. 

Nat. Sc. 1808, 208. 

From the Cretaceous of Alabama. 



PF/rALODUS. 

PeTALODUS ALr.EGHANIENSlS. 

Leidy: Jour. Ac. Nat. Sc. ISoG, 101, riato XVI, Figs. 4 to G; Pr. Ac. Nat. Sc. 

1859, 3. 
tVcariun cxtinvtus. Leidy: Pr. Ac. Nat. Sc. 1855, 411. 
Petalodus destructor. Newberry and Wortbeii : tied. Stir, llliuois, vol. ii, I'al- 

iBontology 35, Plate II, Figs. 1 to .'!. St. John : Haydeu's Eei). Geol. Sur. 

Nebraska, 1872, 241, Plate III, Fig. 5. 

Described page 312, and represented by Fig. 3, Plate, XVII. From the 
Carboniferous formation of Kansas, Nebraska, Iowa, Illinois, and In- 
diana. 

Ichthyodorulites. 

XYSTRACANTHUS. 

Xystracanhus arcuatus. 

Leidy : Pr. Ac. Nat. Sc. 1859, S.- 
Page 312, and represented by Fig. 25, Plate XVII. From the Carbonif- 
erous formation of Kansas. 

'asteracanthus. 

Asteracanthus siderius. 

Leidy : Pr. Ac. Nat. Sc. 1870, 13. 

Described page 313, and represented by Fig. 59, Plate XXXII. From 
the sub-Carboniferous formation of Tennessee. 

Rai.^:. 

ONCOBATIS. 

Oncobatis pentagonus. 

Leidy : Pr. Ac. Nat. Sc. 1870, 70. 
Page 264, and represented by Figs. 18, 19, Plate XVII. From the Plio- 
cene of Sinker Creek, Idaho. 

TRYGON. 

Trygon . 

Indicated Ijy the Ijasal portion of a caudal spine, represented in Figs. 54, 

55, Plate XXXII. It resembles the corresponding ])ortion of the caudal 

spines of our common whip-sting ray, Pastinaca hastata, and would appear 

to have pertained to a species of about the same size. Tlie anterior, shining, 

45 G 



354 

eiiaiueloid surface is strongly wrinkled longitudinally, and the lateral denticles 
are directed downward. 

From the Miocene formation of Virginia. Specimen discovered by Mr. C. 
M. Smith in the blue clay beneath the city of Richmond. 

MYLIOBATES. 

Myliobates . 

Indicated by the basal portion of a caudal spine, represented in Figs. 52, 
53, Plate XXXII. In its relation of breadth to length, in comparison with 
flic spines of ordinary rays, it would appear in the couiplete condition to 
have been upward of 8 inches in length. The specimen, however, becomes 
rather more abruptly narrowed at its upper broken extremity than appears in 
ordinary spines, so that it may have been proportionately shorter than usual. 

The transverse section has almost the Greek e form. In front the spine 
is concave along the middle and convex at the sides ; behind it has the 
reverse arrangement. The lateral denticles are directed downward and 
backward. The anterior enameloid surface is strongly wrinkled along the 
middle groove, but not so much at the sides, except at the 'base of the spine. 
The posterior surface is moderately ridged. 

Specimen fonnd with the preceding in the blue clay of the Miocene forma- 
tion of Virijinia. From Mr. C. M. Smith. 



INDEX. 



[Synonyms aro in italic.'] 



Page. 

Acanthopteri 288 

Acipenser ornatus i 350 

Acrodus 300,352 

Emmonsi 301,352 

Immilis 300, 352 

Adociis I'liomingensis 341 

AgriochoBrus antiquus 216, 319 

latifrons 216,319 

Amia 185,348 

gracilis 188,348 

media 188,348 

uintaeusis 185,348 

Anchippodus 328 

riparius 72, 328 

vetulns 329 

Anchitlieridse 322 

Aucliitlierinm 218, 250, 322, 323 

agreste ...^,. 251,323 

australe 250,323 

Bairdi 218,252,322 

Condoui 218 

Anosteira oruata 174, 341 

AutbracotlieridsB 320 

Antrodanus 338 

Apatoruis 266 

Arclia'otlieyiiim 320 

Artiodactyla 216,317 

Asineops squamifrons 195 

vii'idensis 195 

Asteracauthus siderius 313,353 

Atlantocbelys Mortoni 269, 342 

tnberosus 342 

Aucbenia 255, 317 

californica 255 

hesterna : 255,317 

B. 

Ba€na 160,341 

affinis 163,341 

areuosa 161,341 

uiidata 1()9, 341 

Baptemys 154,341 

wyomingensis 157, 341 

Bison latifrons 253, 318 

Buvidie 318 

C. , 
C'anida; 315 

C'anis indianensis 230,315 



Pago. 

Canis primwrus „ 315 

vafer 315 

CamelidiB 317 

Carnivora 114,227,315 

Cervidse 317 

Cestraciontidfo 352 

Cetacea 337 

Cbameleo pristinus 184,345 

Cbclouia 132,223,260,269,339 

Cbisternon undatnm 169, 341 

Chisternum .-.. 341 

Cladocyclus occideutalis 288, 347 

Cladodus occidentalis 311, 351 

mortifir 312, 351 

Clidastes 281,344 

affinis 283,344 

intermedins 281, 344 

Clupea 195,347 

alta .- 196,347 

bnmilis 195,347 

pusilla 195 

Clnpeidse 347 

Corax Iwterodon 301 

Crocodilia 125 

Crocodilns 125 

aptns 126 

Elliotti 123 

Cycloganoidei 348 

Cynocercus 343 

incisus 269,343 

Cypriuidai 262,348 

D. 



DeliJbiuidte 

Dicotyles 

hesperins 
liristinns. 

Dinoceras 

bxcnstris .. 

bicaris 

miraliilis .. 

Dinosanria 



337 

216,319 

217 

216,319 

232 

95 

334 

.95,108,332,333 
267,338 



Edaiibodon mirilions. 

Edapbodoutidiu 

Elasmobraucbi 

Elepbas 

americanu.s. . 

Cohimhi 



306, 350 
350 
295, 350 
238, 329 
238, 329 
238, 329 



356 



Page. 

Klepbas imporator 329 

Texanus 329 

KlotbtTinm 124,217,320 

iraperator 217,320 

ingens 320 

leutis 124 

Mortoui 125, 320 

supeibum 218 

Emys 140,260 

Carterl ' 137,339 

Haydeni 140, 14&,310 

Jeansi 140,143,340 

petrolei 260,340 

Stevensoniaiiiis 140,141,340 

wyomiugeusis 140, 141, 340 

Enchodus Shniiiardi 289, 347 

Entdodon 320 

Eobasileus 332,334 

Equiila; 321 

Equiis " 242,321 

conqilicatiis 244, 321 

excelsiis 243,322 

major 244,321 

occidentalis 242,322 

pacificiis 322 

parvuliis 252, 323 

Ei'ismatopterus levatiis 195 

Eickseckeri 195 

Eitcrotaph us 212 

Euelephas Cohmibi 330 

Jacksoiii , 330 

Eumjlodus laqueatiis 309, 351 

F. 

Felida; 315 

Felis aiigustus 227, 315 

imperialis 228,315 

Fisbes 184,261,288,346 

G. 

Galeocei'do falcatus 301, 351 

Gauoidei 292,348 

Glyptosaurus 182, 345 

ocellatiis 183 

Grapbiodon viucariiis 337 

H. 

Hadrodiis priscus 294, 350 

Hadrobyus supremos 222, 321 

Hippariou speciosum 247, 322 

Hipposyus formosus 91, 321 

robustior 93, 32 1 

Uolcodus acutiiJens 342 

corjipluviis 276, 34 4 

Holocepbali 306, 350 

Hybeniys arenariiis 174,340 

Hybodoutidic 351 

Hyopsiidiis 75, 320 

niiunscuhis 81, 320 

pauUis 75, 320 



Page. 

Hypaiuia elegaus J89, 349 

Hyraebyus 59,327 

agrarius (jO, 327 

«grcstis 00, 327 

eximius g6, 327 

modestus 67,327 

nanus 67,327 

I. 

Icbtbyodorulitcs 353 

Icbtbyoruis 266 

lusectivora ■ 120 336 



L. 

Labrid.T 

Lacenilia 180, 

Laniu a 

cuspidata 

elegans 

Texana 

Lefalofodon 

Lepido.stens 189, 

atrox 

notabilis 

simplex 

Leptomcryx Evausi 

Lestosanrus corypbajus 

lAmnoliyus 

Icevidens 

latieeps 

rohustus 

Limnolhmum elegans 

Limnotlierium tyraimus 

lAodon dyspelor 

proriger 

Lophiodon 

Bairdiaiius 

modcstus 

nanus 

occidentalis 

parisiense 

Lopbiotherium . . ; 

Ballardl 

sylvaticnni 

Loxoloplwdon 



Lutra . 



l>iscinaria . 



346 
, 285, 344 
303, 351 
305 
305 
305 
332 
, 190, 349 
189, 349 
192, 349 
191,349 
216,317 
276, 344 
57, 323 
323, 325 
326 
326 
84, 320 
83,89 
271,343 
344 
219, 327 
60, 327 
67, 327 
68, 327 
220, 327 
98 
69, 327 
71 
.09,327 
332, 333 
230, 316 
316 



JI. 



Macrosaurus proriger 340 

Jlabicopteri 294 

Mammalia :... 27, 199,211,227, 315 

Manatus iuornatus 336 

Mastodon 231,330 

amcricaniis 237, 330 

anccps 94, 334 

mirificii.s 237, 330 

(ib.scunis 231,330 

Shcpardi 2.35, 330 



3.07 



Pago 

Megacerops 2a9, 335 

coloradensis 239, 335 

Mcgaceratops coloradoeiisis 335 

Megalomenyx 2G0 

niobrarensts 260, 317 

Mery cbippus 248, 322 

mirabilis 250, 322 

Muiycbyus 202 

elegaus 201 

major 201 

medius 201 

Merycodus uecatiis 318 

Meryeochttius 199, 202, 208, 319 

proprius 201 

rusticns 199, 319 

Miacis 310 

Microsus cuspidatiis 81, 322 

Mierosyops 82, 320 

elegaus 8-1, 320 

gracilis 83, 320 

Mosasauria 270, 343 

Mosasaurus 279, 343 

Mitchein 342 

Murida?. , 336 

Mustelid* 310 

Myliobates 353 

My locyprinus robiistus 262, 348 

Mysops Ill, 336 

frateruus 112, 336 

minimus Ill, 330 

N. . 

Notluirclus rohusliof 93, 321 

Notbarctus teuebrosus 86, 329 

Kolhijsaiin)2>s occidmis 287,345 

Notbosaiirus occiduus 287, 345 

O. 

Omni vora 319 

Omomys Carter! 120, 336 

Oucobatis pentagouus 264, 353 

Oligosimus graudaivns.. 286,345 

Oreodontidse . , 318 

Oreodon 201,211,318 

affinis 212 

bullatus 212,318 

Cnlbertsoiii 211,318 

gracilis 211 

bybridiis 212 

major 211 

occidentalis 3] 8 

snperbu/* 211,319 

Osteoglossum encaustum 195 

Otodus divaricatns 305, 351 

Oxyrbiua 302, 303, 351 

extenta 302, 351 

P. 

Palajacodoii 122, 336 

venis 122, 336 



raso. 

Pal;cosyops 27,323 

biimilis 58,326 

Junius 57, 326 

jiiiiioy 326 

laliapf! 325,326 

major 45,326 

minor 72, 328 

paludosus 28, 325 

Palaucbeuia magna 255 

Paramys 109, 335 

delicatior 110,335 

delicatissimus Ill, 335 

delicatus 110, 335 

Patriofelis ulta 114, 316 

Perissodactyla 27,219,321 

Petalodus allegbanieusis 312, 353 

destructor 313, 353 

Pbareodus acutus 193, 349 

Pbasgauodus dirus 289, 347 

Pimelodus antiquus i 193, 348 

Placoganoidei 350 

Plagiostomi 295,311,351 

Platecarjms 342, 344 

tuherosiis 342, 344 

tympaniticus 342 

Platygonus Coudoni 217 

Poicilopleuron Buclilaudi 268 

valeus 267,338 

Polycotylus latipinnis 279 

Pontobasileus tuberculatus 337 

Proboscidea 93, 231, 329 

Procamelus occidentalis 258, 317 

niobrarensis 317 

robustus 258, 317 

yirginiensis 259,317 

Protamia 185,348 

Protautoga conidens 346 

Protocamehis ..'. 317 

Protobippus 248,322 

perditus 249,250,322 

idaeidus 248,322 

Protostega gigas 269 

inptiiiiia 342 

tiilnro!ia 269, 342 

Ptycbodus Morton i 295,352 

occidentalis 298,352 

polygyrus 352 

Wliipployi 300,352 

Pycnodus 292,349 

carolincnsis 294,350 

faba 292,349 

robustus 293,350 

It. 

Eal:r 264,353 

Reptilia 125,338 

Kcptilcs 267 

lihaniphosauriis 271,343,344 

Rbinoceros 220,328 

anncctaus 328 



358 



Ehiuoceros hesi>eii us 

occidciitalis 

oregoueuiiis 

jjaciflcus 

Uhinosaurns 

d!/8j)elor 

proriger 

Ehomboganoidei 

Ebyucbothei'inm 

Rodenti.a 

Enminantia - 199, 2U, 

S. 

Saniva 

Saniwa ensideus 

major 

Sauropterygia ■ 

Sciuravus 

nitidus 

undans 

Scinridie 

Sicarius exiinctus 

SiluridoB - 

Sinopa 

eximia 

rapas 

Sirenia 

Soliduugiila 208,218; 

SpliargididjB 

Sphy rsBuidio 

SqualidiB 

Styleniys 

Culbertso7ii 

otrgonensis 

nchrascensis 

niohrarfiisis 



Page. 

2ii0, 328 

328 

328 

221, 328 

271 

343 

344 

349 

237, 330 

109, 335 

953,317 



Suidse 



181, 344 

181,344 

181, 345 

286, 345 

113, 335 

113 

113 

335 

353 

290, 348 

11(3,316 

118,316 

116,316 

336 

242, 321 

342 

288, 347 

351 

223 

339 

226, 340 

224. 339 

225. 340 
319 



Page. 

Testudo Culberlsoiii 339 

hemisjjherica 339 

lala 339 

nebrasceusis 339 

niobrareusis 340 

oregouensis 340 

Tetralophodon mirifictis 330 

Tylosaunis dyspelor 271, 343 

jiroriger 274, 344 

Tylosteiis ornatus 285, 345 

Tinociras 331 

aneeps 94, 334 

grandis 94,334 

Titaiiolhei'inm aneeps 94, 334 

Triacodou falax 123 

Triouyebidaj 341 

Trioujx 176, 180, 341 

guttatus 176, 341 

iiintacusis 178,342 

Trogosus castoridens 71, 32S 

vclulus 75, 329 

Tiygon 353 

U. 

Uintacyou edax 118, 310 

vorax 120,316 

Uintamastix 331 

atrox 94, 107, 333 

Uintatherium 93,331 

aucep.s 334 

nuruhile . 333 

robustiim 93,96,333 



Tautoga 346 

Teleostel 288,346 

Tdmatheiium 323 

Testudinida* 339 

Testudo Corsoni 132, 339 



Vnlpavus palustris 



118 



W. 



Wasbakius iusignis ._ 123, 336 

X. 

Xiphactiiius audax 290,348 

Xystracautbus arcuatns 312, 353 

Z. 

Zeuglodontia . 337 



EXPLANATION OF PLATE I. 



Fig. 1. Oreodon supeebus: 

A side view of a skull, witli the base of tbe cranium iuvested in tlie matrix. Specimen ob- 
tained by Rev. Thomas Condon on John Day's River, Oregon. One-half the natural size. 

Figs. 2,3. MEGACfiROPS COI.ORADENSIS : 

Fig. 2. Upper view of the nasal extremity of the face with a pair of horn-cores. Oue-half 

the natural size. 
Fig. 3. Front view of the same specimen 



U. S. Geological SuTvay of the Temtoneo. 



Plate I 






T SINCLAIR ft SON. PHILADELPHIA. 



OR,EODON SUPERBUS. % 



2 % MEGACEROPS COLOR/ DENSI3 '^ 



EXPLANATION OF PLATE II. 



Fig. 1. LOPHIODON OREGOXENSIS : 

Two upper molar teeth, much worn and seen on theii- triturating surfaces. Specimen from 
Bridge Creek, Oregon. Natural size. 

Fig. 2. Megacekops coloradensis : 

Side view of the same specimen as that of figures 2, 3, of Plato I. One-half the natural size. 

Figs. 3, 4. Elotherium superhuji : 

Fig. 3. Portion of a lower canine tooth, natural size. From Bridge Creek, Oregon. 
Fig . 4. Crown of an anterior premolar, natural size. From John Day's River, Oregon. 

Fig. 5. A^■c•HrrIIERIUM Condoni : 

A mutilated upper molar tooth, natural size. From Oregon. 

Figs. 6,7. Rhinoceros pacificus: 

Fig. 6. An upper molar seen on the triturating surface, natural size. From Alkali Flats, 

Oregon. 
Fig. 7. An upper last premolar, seen on the triturating surface, natural size. From Alkali 

Flats, Oregon. 

Figs. 8,9. Rhinoceros hesperius(?) : 

Fig. 8. An upper last molar, seen on the triturating surface, natural size. From the Condon 

collection of Oregon. 
Fig. 9. An inferior molar, seen on the triturating surface. 

Fig. 10. Patriofelis ulta: 

Portion of the right ramus of the lower jaw, half the natural size. It contains the remains 
of five teeth behind the position of the canine. From near Fort BriJger, Wyoming. See 
page 114. 

Figs. 11, 12. Hyrachyus agrarius : 

Fig. 11. Left ramus of the lower jaw, one-half the natural size. Specimen obtained by 
Professor Hayden on Smith's Fork of Green River, Wyoming. 

Fig. 12. Portion of the left ramus of the lower jaw of a young animal, natur.il size. It con- 
tains the temporary series of teeth behind which the first of the true molars is inclosed 
within the jaw. From Black's Fork of Green River. Hayden's collection. 

Fig. 13. Hyrachyus modestus : 

A first or second upper molar of the left side, slightly larger than natural. From Smith's 
Fork of Green River. Hayden's collection. 

Fig. 14. Hyraohy'US nanus : 

Portion of left ramus of the lower jaw, with two premolars and the three molars, natural 
size. Obtained by Dr. Joseph K. Corson from Grizzly Buttes. 

Fig. 15. Diseased calcaneura (hyperostosis) of Merycochcerus uusticus. From Sweetwater River. 
Hayden's collection of 1H70. 

Fig. IG. Oreodon superbus : 

Portion of right ramus of lower jaw, with the three premolars and first molar; natural size. 
Condon collection of Oregon fossils. 



D b G.eological Survey of the TerntorieB 



Plate ri 



1 



*fci»^ "; ,'Sa»= 





u 

m 



\-\ 




13 




p^# 



^*^^^«-4,.^4^ 



;^. 





X 





/^ 



T- StNCW/'H A SON ^■■^lLA^:>ELPMIA 



1 LOPHIODCN. 

2 MEGACEROPo. -^ 



S. 4 ELOTHERIUM. 1 6-9 RtllNOCEROS 
S ANCHr)'Hl;;RirMj 10. PATRIOFELLi 
16 OREODON. 



il-hi HfRACHY'ie 

i& iVlERYCOCaCERaS 



EXPLANATION OF PLATE III. 



Figs. 1-3. Merycochcerus rusticus. Figures of the natural size. Specimeus from Sweetwater River, 
Wyoming. Hayden's collection of 1870. 

Fig. 1. Upper jaw, with a nearly complete series of teeth, the last molar introduced from 
another specimen. 

Fig. 2. Front view of the same specimen, exhibiting the high alveolar border and the nar- 
row nasal orifice. 

Fig. 3. Lower jaw, witli a full series of molar teeth. 

Fig. 4-6. Testudo or Stylbmvs niobrarensis. Figures of the natural size, except Figure 6, which is 
one-half the size of nature. From the Niobrara River. Ilaydeu's collection of 1857. 
Fig. 4. Internal view of the fore-part of the plastron. 
Fig. .5. The last vertebral and the pygal plates. 

Fig. 6. Internal view of a posterior portion of the carapace, exhibiting the costal capitula, 
and the processes for conjunction with the pelvic girdle. 



U. S. Geological Sur-vey oC the Terntonec 



Plato III. 




. SINOLAIB * BON. PMlUAOtCPHIA 



]-S MERYCOCHOERUS RUSTICU3. | 4-6. STYL£.M^S NIOBRARENSIS. 



EXPLANATION OF PLATE IV. 



Figures all of the natural size. Specimens all from the Bridger tertiary formatiou of 
Wyoming. 

Figs. 1-8. Pal/EOsyops paludosus: 

Fig. 1. A mutilated upper canine of the supposed female, from the same individual as the 

specimens of figures 5-8. 
Fig. 2. Mutilated canine of the supposed male, from the specimen of the following. 
Fig. 3. A complete series of molar teeth aud the mutilated canine of the left side of a fine 

specimen discovered at Grizzly Buttes by Dr. J. Van A. Carter. View of the triturating 

surfaces, partially worn, of the molar teeth ; from a supposed male. 
Fig. 4. Outer view of the crowns of the same molar series. 
Fig. 5. A complete series of molar teeth, discovered by Dr. Carter ou Henry's Fork of Green 

Kiver. View of the triturating surfaces; more worn than in the preceding specimen. 

From a supposed female. . 

Fig. G. Quter view of the anterior two premolars of the same specimen. 
Fig. 7. A third upper premolar, left side. Specimen from Henry's Fork. Hayden's coUec- 

tiou of 1870. 
Fig. 8. Lateral view of an upper incisor. Specimen probably from the same individual as 

that of Fig. 5. 

Figs. 0-18. Hyrachyus agrarius : 

Fig. 9. Outer view of the crowns of an upper series of molar teeth. 

Fig. 10. View of the triturating surfaces of the same teeth. From a specimen discovered by 

Dr. Carter near the Lodge-pole trail, eleven miles from Fort Bridger. All the teeth con- 

.siderably worn. 
Fig. 11. An upper second true molar, left side. Found by Dr. Carter on Henry's Fork of 

Green River. 
Fig. 12. An upper last premolar, left side, but little worn. Specimen found by Dr. Joseph 

K. Corson at Grizzly Buttes. 
Fig. 13. A iJortion of the lower jaw; from the same individual as Figs. 9, 10. It contains 

part of the lateral incisor, the canine, and the premolars. 
Fig. 14. View of the triturating surfaces of the premolars, from the same specimen. 
Fig. 15. Outer view of a second lower molar, from the same individual. 
Fig. 16. Triturating surface of the same specimen. 
Fig. 17. An upper canine, found at Grizzly Buttes by Dr. Corson. 
Fig. 18. A lower iucisoi, from the same individual as Fig. 13. 

Figs. 19, 20. Hyeaciiyus exijiius. Specimen found by Dr. Carter on Henry's Fork of Green River. 

Fig. 19. Fragment of the left side of the lower jaw, containing the last premolar and tho 

greater part of the tirst molar. 
Fig. 20. View of tho triturating surfaces, much worn, of the same teeth. 



U. S, Geological Survey of the Terntoriee. 




T^ SINCLAIR * SON, PHILAOCLPMIA 



1-8 PALAEOSYOPS PALLTDOSUS | 9-18. HYRACHYUS AGRARIUS. 

ly au. HYRACHYUS EXilvUaS. 



EXPLANATION OF PLATE V. 



All the figures of the natural size except Fig. 11, -which is one-half the size. 

rigs. 1-3 Trogosu.s castoridens. A lower jaw, discovered iu the vicinity of Fort Bridger by Dr. 

Carter. 
Fig. 1. View of the left ramus of the jaw. 
Fig. 2. Triturating surface of the second true molar, much worn. The other molars are too 

much injured to ho characteristic. 
Fig. 3. Front view of the jaw, exhibiting the large rodent-like incisors. 

Figs. 4-11. Pal^osyops paludosus : 

Fig. 4. An upper last premolar, the triturating surface much worn. From Henry's Fork. 
Hayden's collection. 

Fig. 5. An upper last premolar, nearly unworn. This is one of the original specimens upon 
■which the genus and species were established. From Church Buttes. Hayden's collec- 
tion of 1870. 

Fig. 6. Outer view of a last upxier molar, left side. Henry's Fork. Hayden's collection 
of 1870. 

Fig. 7. Triturating surface of the same specimen ; the outer fore-part much fissured, with 
the i)ortions displaced and the single inner lobe partially broken away. 

Fig. 8. Outer view of a second njiper molar, from the opj)Osite side of the same individual. 

Fig. 9. The triturating surface, with the outer lobqs much worn. Figs. 6-9 are from 
specimens, which were attributed to the same species at the time of the original uotice of 
it in the Proceedings of the Academy of National Sciences, Philadelphia, 1870, p. 113. 

Fig. 10. View of the triturating surfaces of the last two premolars and the molars from the 
specimen represented in the next figure. 

Fig. 11. Left ramus of a lower jaw, containing the teeth just indicated. This fine specimen 
was discovered by Dr. Carter thirteen miles southeast of Fort Bridger. 



U. H Geological Survey of the Territoriee. 



Plate V. 




T. SINCLAIR d> SON, PHILADELPHIA 



1-S TROGOSUS GASTORIDENS, 



4-11. PALAEOSYOPS PALUDOSUS. 



EXPLANATION OF PLATE VI. 



Figs. 1-9. Hyopsodus paulus. All of the natural size except Figs. 2, 5, 8, 9, which are niagnified four 

diamoters. 
Fig. 1. Right side of lower jaw, with the three molars. From au individual past maturity. 

Specimen from which the genus and species were firsfeuoticod. 
Fig. 2. Triturating surfaces of the molars of the same specimen. 
Fig. 3. Left side of lower jaw, with last premolar and the three molars. Specimen obtained 

by Dr. Corson at Grizzly Buttes. 
Fig. 4. Eight side of lower jaw, with last premolar and the molars, but slightly worn. 

Specimen obtained by Dr. Carter. 
Fig. 5. Triturating surfaces of the teeth from the same. 

Figs. 6, 7. Left side of two lower jaws containing the molars. From mature but compara- 
tively young individuals. Dr. Carter. 
Fig. 8. Series of the back two premolars and the molars of the right side. From a specinleu 

loaned by Dr. Carter. 
Fig. 9. First and second lower molars of the right side. From another specimen loaned by 

Dr. Carter. 

Figs. 10, 11. MicROsns cuspidatus : 

Fig. 10. Portion of left side of lower jaw, with back two molars, natural size. Specimen 

from Black's Fork of Green -River. 
Fig. 11. Triturating surfaces of the two molars, magnified four diameters. 
Fig. 12. Portion of right side of lowcfi- jaw, probably pertainiug to the last-named animal. 

It coutaius the roots of the molars and the last premolar, the triturating surface of which 

is represented in Fig. 13, magnified four diameters. Specimen obtained by Dr. Carter near 

Fort Bridger. 

Figs. 14-17. MiCRO.SYOPS gracilis: 

Fig. 14. Left side of lower jaw with the molars, natural size. Fig. 15. Triturating surfaces 

of the molars, magnified four diameters. Specimen obtained at Grizzly Buttes by Dr. 

Carter. 
Fig. 16. Left side of lower jaw, with the second molar and portions of the others, natural 

size. Fig. 17. The triturating surface of the second molar magnified four diameters. 

Specimeu obtained by Dr. Carter at Grizzly Buttes. 

Figs. 18-22. Hyopsodus padlus: 

Fi"-. 18. Right upper jaw, with three premolars and the molars, magnified 'two diameters. 

Fig. 19. Tritiu-atiug surfaces of the teeth magnified four diameters. Specimen obtained 
by Dr. Carter at Grizzly Buttes, aud apparently pertaining to the same individual as that 
of Fig. 14. 

Fig. 20. Triturating surfaces of the right upper molars, magnified four diameters, from a 
second specimen. Dr. Carter. 

Fig. 21. Triturating surfaces of back two premolars and first molar of the left side, magni- 
fied four diameters. Obtained by Dr. Carter at Lodge-polo trail. 

Fi"'. Hi. Triturating surfaces of upper secoud and third premolars of right side, magnified 
four diamoters. Dr. Carter. 

Figs. 23-25. PARAMY.S del!Catu.s : 

Fig. 23. Right side of lower jaw, with all the molars, natural size. Fig. 24. Triturating 
surfaces of the molars except the last, which is broken away csccptiug the outer portion, 
magnified three diameters. Grizzly Buttes. Dr. Carter. 
Fi". 2.'>. Triturating surfaces of the molar series, except the last, of the lower right side, 
magnified three diameters. From another specimen loaned by Dr. Carter. 



PLATE VI. 



Figs. 26, 27. Paramys uelicatiok : 

Fig. 26. Left side lower jaw, with the second molar, natural size. Grizzly Buttes. Dr. 
Carter. Fig. 27. Triturating surface of the second molar, magnified three diameters. 

Figs. 28, 29. Paramys delicatissimus : 

Fig. 28. Eight side of lower jaw, with all the molars, natural size. Grizzly Buttes Dr. 
Carter. Fig. 29. Triturating surfaces of the molar series, magnified three diameters. 

Fig. 30. ScitjRAVUS(?) Triturating surface of a lower left third molar, magnified eight diameters. From 
a portion of the lower jaw obtained at Grizzly Buttes hy Dr. Carter. 

Figs. 31,32. My'.sops minimus: 

Fig. 31. Right side of lower jaw, with third and fourth molars, magnified two diameters. 
Fig. 32. Triturating surfaces of the teeth, magnified eight diameters. Dr. Carter. 

Figs. 33-35. LOPHIOTHERIUM SY'LVATICUM : 

Fig. 33. Portion of left side of lower jaw, with last premolar and first and last molars, 
natural size. Fig. 34. Triturating surfaces of the last premolar and first molar. Fig. 35. 
Triturating surface of the last molar. Specimen from Henry's Fork of Green River. 

Figs. 36, 37. NOTHARCTUS TENEBROSUS : 

Fig. 36. Eight side of lower jaw, with canine and all the molar series except the first pre- 
molar, natural size. Fig. 37. The triturating surfaces of the molars, magnified two 
• diameters. Specimen from Black's Fork of Green Elver. 

Figs. 38, 39. HipposTus roMosus (?) 

Fig. 38. Triturating surface of a lower right second molar, magnified two diameters. From 

a jaw-fragment from near Fort Bridger. Dr. Carter. 
Fig. 39. Trituratiug surface of a left lower first molar, magnified two diameters. From a 
jaw-fragment obtained by Dr. Carter near Fort Bridger. 

Fig. 40. HiPPOSYUS ROBUSTIOR : 

Triturating surface of a left lower second molar, magnified two diameters. From Henry's 
Fork of Green Elver. Professor Haydeo. 

Fig. 41. HiPPOSYUS FORMOsus : 

Triturating surfaces of the upper left first and second molars, magnified three diameters 
Specimen firom near Fort Bridger. Dr. Carter. 

Fig. 48. Hyrachyus nanus.: 

Triturating surfaces of the back two premolars, and the molars, magnified one and a half 
diameters. Taken from the left side of the lower jaw of the same sjiecimeu represented 
in Fig. 14, of Plate II. Specimen obtained by Dr. Corson at Grizzly Buttes. 

Fig. 43. Trogosus vetulus, probably Anchippodus : 

Eight lower incisor, natural size. From near Fort Bridger. Dr. Carter. 

Fig. 44. SiNOP.t^ RAPAX: 

Portion of left side of lower jaw, with last premolar and first molar, natural size. From 
Grizzly Buttes. Dr. Carter. 

Fig. 45. SiNOPA ExiMiA : 

Portion of left side of the lower jaw, supposed to belong to a smaller species of the former 
natural size. From Grizzly Buttes. Dr. Carter. 

Fig. 46. Pal^acodon verus : 

Penultimate molar of the upper left side, maguitied four diameters. From Lodge-polo trail. 
Dr. Carter. 



ij S. Geological Kurvey oi' the Territories. 



Plate VI 




pec%iii\ 



J' tv 









1-9. HYOPSODUS PAULUS. 
10, 11. MICROSUS CUSPIDATUS 
12, 13. 

14-17. MICROSYOPS GRACILIS 
18-22. 

23-26. PARAMTS DELICATDS. 
26, 27 P DELICATIOR. 



28, 29 P DELICATISSIMUS. 

30. 

31, 32. MTSOPS MINIMUS. 

33-36. LOPHIOTHERItJM STLVATICUM. 

36, 37. NOTHARCTUS TENEBROSUS. 

38, 39, 

40, 



T SINCLAIR a SON LITH PHILAD* 



41. 

42. HYRACHYUS NANUS. 

43 ANCHIPPODUS VETULUR 

44, SINOPA RAPAX. 

48. , 

46. PALvEACODON VERIS 



EXI^LANATION OF PLATE VII. 



All tbo figiu'cs are of tbo natural size, except Fig. 10, wliicb is retluced to oue-balf the diaui- 
eter of the original. 

Figs. 1-5. Merycocbcerus rusticus. From specimens obtained on Sweetwater River, Wyoming, by 
Professor Haydeu's party in 1870. 

Fig. 1. Series of upper molars of tbc right side, viewed on their tritnrating surfaces. The 
last tooth bad not entirely protruded, and m the lirst ono the median enamel-pits are 
nearly obliterated. 

Fig. 2. Upper last premolar and molar of the left side, of the temporary series. 

Fig. 3. Upper second and third premolars of the left side, of the permanent scries. The trit- 
urating surfaces but slightly -worn. 

Pig. 4. Outer view of the same teeth, in a small jaw-fragraeut. 

Fig. 5. Symphysis of the lower jaw, with the four incisors on each .side. 

Fig. fi. Mekycochceiuis pkoprics. First and second upper molars of the right side. From a specimen 
obtained on the Niobrara River, by Professor Hayden, in 1857. 

Figs. 7-11. Oreodon supercus. From specimei^s discovered in Oregon by the Rev. Thomas Condon. 
Fig. 7. Last lower molar of the right side, viewed on the triturating surfixco. 
Fig. 8. First and part of the second molars, from the same jaw-fragment as the preceding 

figure. 
Fig. 9. The three lower jjremolars of the right side, viewed ou their triturating surfaces. 

From the same specimen as Fig. 16, Plato II. 
Fig. 10. Upper view of the intermediate portion of the face, one-half the natural size. 
Fig. 11. View of the inner surface of a lower canine, from the left side of a specimen of a 

jaw, which lies with its outer face imbedded in a hard mass of rock. 

Fig. 12. Oreodon Culbertsoni. A series of upper true molars of the left side. Specimen discovered 

by Mr. Condon on John Day's River, Oregon. 
Figs. 13, 14. DicoTYi-ES PRI.STIN0S. Specimens in the Condon collection of Oregon fossils. 

Fig. 13. Triturating surface of a lower penultimate molar. 

Fig. 14. Outer view and view of the triturating surface of a lower last molar. _ 
Fig. 15. Anchithekium Bairdi. An upper right molar. From the Condon collection. 

Figs. 16, 17. ANcniTHERiUM agreste. From a specimen found ou Red Rock Creek, one of the head 
streams of the Jefferson Fork of the Missouri. Obtained by Professor Hayden in 1871. 

Fig. 16. Lower last premolar and first molar of the left side. Triturating surface much 
worn. 

Fig. 17. Last molar, from the same specimen of the jaw as the former. 

Figs. 18, 19. Felis ACGUSTU.S. Specimens discovered by Professor Hayden on the Loup Fork of the 
Niobrara River, Nebraska. 
Fig. 18. Portion of the right premaxillary, containing the second incisor, viewed in front. 
Fig. 19. Upper sectorial molar of the left side, viewed externally. 

Fig. 20. Patriofells ulta (?) A premolar, probably of the up^ier jaw. Specimen found by Dr. Carter in 
the vicinity of Fort Bridger, Wyoming. 

Figs. 21-23. Teeth of a carnivore, undetermiued. Obtained by Professor Haydeu's party on Henry's 
Fork of Green River, Wyoming. 
I<'')g. 21. Outer view of the crown of an anterior premolar. Fig. 22. tljiper view of the same. 
Fig. 23. Outer view of the crown of a eauiue tootli. 



PLATE VII. 



Figs. 24, 25. Rhinoceros pacikicus. A left iuferior molar tooth, from Bridger Creek, Oregon, belonging 
to the Coiulou collection. 

Fig. 24. View of the outer part of the crown. Fig. 25. Triturating surface of the same speci- 
men. 

Fig. 26. A canine tooth of au undetermined animal, probably of a large carnivore, but it may 
be of an Elotherium-like pachyderm. The specimen belongs to the Condon collection of 
Oregon fossils, and is labeled '■ Alkali Flats." 

Fig. 27. Elotherium ihperatok. a supposed incisor tooth, inner view. Specimen labeled " Bridge 
Creek," and belonging to the Condon collection of Cregor fossils. 

Figs. 28, 29. Elotherium Mortoni? An incisor tooth, obtained by Mr. Peiroe, of Denver, twenty miles 
southeast from Cheyenne City, Wyoming. 
Fig. 2H. Inner view of the tooth. Fig. 29. Outer view of the same. 

Fig. 30. Canine of an undetermined carnivore. It resembles the iuferior canines of a bear^ 
but is more comi^ressed. Specimen discovered by Professor Haydeu on White River, Da- 
kota, in 1866. The crown is compressed conical, with the inner surface defiued in the 
usual manner by acute borders. The faug exhibits a gibbous character. Length of crown 
11 lines ; breaflth at base, 8 lines ; thickness, H lines. 



a. S. Geological Survey of the Tarntoriea. 



Plate VII. 




iSmClMtiSOHUTH PHtU 



EXPLANATION OF PLATE VIII. 



Figures all oue-half the diameter of uature. 

Fig. 1. A lumbar vertebra of a crocodile. From Little Sandy River. Haydeu's collection of 
1870. (Crocodilus Elliotti.) 

Fig. 2. Crocodilus .vptus : 

A cervical vertebra, found on South Bitter Creek, Wyoming. 

Fig. 3. A first caudal vertebra of a crocodile. From Little Sandy River. Hayden's collec- 
tion of 1870. 

Figs. 4-6. Crocodilus Elliotti. Hayden's collection of 1870. 

Fig. 4. Portion of tbo left maxillary, containing tUe fourth and fifth teeth of that bone 

From the junction of Big Sandy and Green Rivers. 
Fig. 5. Upper extremity of a left femur. From near Little Sandy River. 
Figs. 6, 7. Upper view of a large portion of the skull. Found by H. W. Elliott, ou Little 
Sandy River. 
. Fig. 8. Left ramus of the lower jaw of a larger individual, or jierhaps of a larger species. 
Discovered in the vicinity of Fort Bridger by Dr. Josei)h K. Corson, and presented by him 
to the Academy of Natural Sciences of Philadelphia. 



U. S. Gfoloc^icai Sui-v'»T .;i in-r T^rnioT.e 




Plate VIII 






"^-c^ 











^ - V 





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^^ 











I. SINCLAIB a SON. PulLAOELFm* 



CROCODILES. H SIZE 



EXPLANATION OF PLATE IX. 



All the figures lialf the natural size. 

Fig. I. Trionyx guttatus : 

Portion of a carapace, consisting of the third to the sixth vertebral iilates, inclusively, 
together with parts of the contignous costal plates. Specimen obtained at Church Buttes 
during Professor Hayden's exploration of 1868. 

Figs. 2-6. Emys wyomingensis : 

Fig. 2. Portion of a carapace comprising the vertebral jjlates from the first to the eighth 
inclusively, together with small portions of some of the contiguous costal jilates. 
Specimen, originally referred to Emijs Sterensoniamis, obtained l)y Dr. Carter in the 
vicinit.'^of Fort Bridger, and presented by him to the. Smithsonian Institution. 

Fig. 3. Portion of a plastron, ivhich accompanied the jireceding specimen and was origi- 
nally referred to E. Slcrcnsoiiianus. 

Fig. 4. Anterior fragment of another plastron, accompanying the former two specimens, and 
likewise referred to E. Steveiisoriiaiuis. 

Fig. 5. An episternal, upon which the species Emys wijomiiif/ensiii was first noticed. Specimen 
found by Dr. Carter near Fort Bridger. 

Fig. 6. Central portion of a carapace, originally attributed to Emys Saydeiii. Specimen 
obtained near Fort Bridger. Haj'den's collection. 

Fig. 7 Emys petrolei: 

Two episternals from different individuals. Specimens from Hardin County, Texas. 







CO 



CO 

D 
H 

o 



EXPLANATION OF PLATE X. 



Represents the nearly complete shell of Eai YS wyomingensis, one-lialf the natural size. It was originally 
referred to a species with the name of Emys Jeaneni. Specimen obtained from the vicinity 
of Fort Bridger, dnring Professor Hayden's exploration of 1870. 

Fig. 1. View of the plastron. 

Fig. 2. View of the carapace. 




o 



03 



EXPLANATION OF PLATE XI. 



Testudo Oorsoni : 

Both specimens iieitainetl to the same shell, aurt were originaUy described uuder the name 

of Eiiii/^ Carteri. They were discovered near Fort Bvldger by Dr. Carter, and presented to 

the Academy of Philadelphia. 
Fig. 1. The greater part of the iilastron, its anterior extremity to the right, one-third the 

natural size. 
Fig. 2. The anterior intermediate portion of the carapace, its front to the left, one-half the 

natural size. 



U. S, Geological Survey o? the Terntonea 



Plate XI, 




T, SINCLAIR l> SOM. OMiLAOELPHIA, 



EXPLANATION OF PLATE XII. 



Baptemys wyomxngensis : 

Figures one-third the natural size. Specimen discovered at Church Buttes, Wyoming, by 
Mr. O. C. Smith, of Leverett, Massachusetts, while engaged in service of the Union Pacific 
Eailroad. It now belongs to the museum of the Academy of Natural Sciences of Phila- 
delphia. 

Fig. 1. View of the carapace. 

Fig. 2. View of the sternum. 




s 

m 
o 



CO 

Ph 

< 



EXPLANATION OF PLATE XIII. 



BaSna akenosa : 

Figures one-half the natural size. 

Figs. 1, 2. Specimen on which the genus and species were originally estahlished. Dis- 
covered at the junction of the Big Sandy and Greeu Rivers, Wyomiug, during Profe.ssor 
Hayden's exploration of 1870. 

Fig. 1. View of the carapace. 

Fig. 2. View of the plastron, its anterior extremity lost. 

Fig. 3. View of the plastrou of another specimen, originally referred to a species with the 
name of Baina affinis. It was discovered by Dr. Carter at Chnrch Buttes, and was pre- 
sented by him to the Academy of Natural Sciences of Philadeljihia. 



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EXPLANATION OF PLATE XIV. 



Chisternon dndatum, originally referred to Bai^ita niiilata. Figures oue-balf the natural size. Speci- 
men discovered in the vicinity of Fort Bridger by Dr. Carter, and presented by him to the 
Academy of Natural Sciences. 

Fig. 1. View of the carapace ; the sutures scarcely visible. 

Fig. 2. View of the greater portion of the plastron, with the left border of the carapace. 
The crucial suture of the plastron is visible, from which the genus received its name. 



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:igi^y*^' 



EXPLANA'J'ION OF PLATE XV. 



Figs. 1-5. Ba^ na arenosa : 

Fig. 1. Anterior extremity of the i)lastron,'eshil)itiiig the two pairs of gular scute areas. 

From the same specimen as Fig. 3, of Plate XIII. One-half the natural size. 
Fig. 2. Anterior extremity of the plastron, from another specimen found by Dr. Carter on 

Henry's Fork of Green River. Tlie gular scute areas are larger, and the surface of the 

plates is conipurafively smooth. One-half the natural size. 
Fi"'. 3. From a specimen fonud by Dr. Corson at Grizzly Buttes. It is of greater proportiou- 

ate breadth than the former, and presents x want of symmetry in the gular scute areas. 

One-half the natural size. 
Figs. 4, 5. Of the natural size. From a young specimen obtained by Professor Haydeu's 

party "at the junction of Big Sandy ^nd Green Rivers. It retains the sutures, which are 

obliterated in the preceding mature specimens. 
Fig. 4. Inferior view. 
Fig. 5. Superior view, exhibiting the trident form of th3 eutosternal bone. 

Fi"-. 6. Baptemvs wyomingensis. One-half the natural size. A portion of the anterior extremity of 
the plastron, from a specimen obtained by Professor Haydeu's party at Church Buttes. It 
presents no distinction between gular and humeral scute areas. 

Fig. 7. Tbstudo CoRSONi. Anteriorextremityof a plastron, one-half the natural size. From a specimen 
discovered by Dr. Corson at Grizzly Buttes. 

Fio-, 8. Supposed turtle egg, natural size. A frequent fossil of the indurated clays of the Bridgcr bf'ds. 
They are usually about the size of the specimen represented, though quite small ones are 
also fonud, like that represented in Fig. 01, Plate XXXII. They have an outer calcareous 
crust, and are iilled with the same material as the imhe<ldiug matrix. Usually one end is 
truncated and rough, as if the shell had been originally broken. Sometiuies the truncated 
end apitears covered with a low conical disk, resembling an operculum, as represented in 
Figs. 60, 61, Plate XXXII. 

Fi'^ 9. Hybemys arenakius. A marginal plate, exhibiting the bosses ou its outer extension. From 
a specimen found by Prt)fes8or Haydeu's party on Little Sandy Creek. Natural size. 

Fig. 10. Stylemys OREGONEN.SI8. A vertebral plate, one-half the natural size. From Crooked River, 
Oregon. 

Figs. 11-13. NoTHOSAUKOPS OCCLDUUS. Three views of a vertebra, natural size, from .i specimen ob- 
tained by Professor Haydeu on Moreau River. 
Fig. II. Side view of the centrum, exhibiting the sutural surface of the neural arch. 
Fig. 12. Upper view of the same. 
Fig. 13. View of the anterior end. 

Figs. 14, 15. Saniwa. Natural size. 

• Fig. 14. Saniwa major. Distal extremity of a humerus, from a specimen found by Dr. 
Carter at the Lodge-pole trail, ou Dry Creek, Wyoming. 
Fig. 15. Saniwa ensiden.s. Two dorsal vertebrai as they lie iu the matrix, inferior view, 
from a specimen obtained near Granger, Wyoming, during Professor Haydeu's exploration. 

Figs. lB-18. Antrodemus. In the text, page 267, under the name of Poicilopleuron valens. Figures 
one-balf the natural size. Three views of one-half of a vertebra, from Middle Park, 
Colorado. 

Fjo-. 16. End view, exhibiting the articular surface of the centrum. 

Fig. 17. Side view. 

Fig. 18. View of the Ijroken surface of the vertebra, exhibiting the large areola^ of the 
interior of the centrum, inclosed by thick walls of compact substance. 



U. S. G.oological Survey of the Territories 



Plate X.V" 



\- 











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N njk 










5& 






T. SINCLAIR & SON, PHILADELPHIA 



1-5 BAENA ARENOSA, >^ 
6. BAPTEMYS. >:^. 
7 TESTUDO CORSON] ;^ 
9. HYBEMYS. 



10 STYLEMYS yi 

11- IS. NOTHOSAUROPS. 

14 15. SANIVA 

16-18 ANTRODEMtrS. }4 



EXPLANATION OF PLATE XVI. 



All tbe figures of tlio natural size, except Figs. 13-17. 

Figs. 1-6. Ano.steira ohnata : 

Fig. 1. Portions of tlio carapace. 

Fig. 2. Portion of the same specimen, with portions of tlie plastron. Siiecimens collected 

by Dr. Carter in the vicinity of Fort Bridger. 
Fig. 3. Inner view of tbrfee oostals, from a portion of the same specimen as Fig. 1, exhibiting 

the costal capitula. 
Fig. 4. A third marginal plate from a larger individual. Dr. Carter. 
Fig. 5. A fourth marginal plate of the left-side of another individual. From Washakia ; 

collected by James Stevenson. 
Fig. 6. Section of a i^ygal plate. From a specimen found bj' Professor Haydeu at Church 

Buttes. 
Fig. 7. Ilium of a turtle. Obtained at Grizzly Buttes by Dr. Carter. 

Figs. 8, 9. BjuSna arenosa : 

Fig. 8. Ilium of the right side, outer view. Fig. 9. Sacrum, inferior view. Sjiecimens ob- 
tained from portions of the matrix, pertaining to the specimen of the shell represented in 
Figs. 1, 2, Plate XIII. 

Fig. 10. Opisthocoelian caudal vertebra of a turtle. From near Lodge-ijolo trail. Dr. 
Carter. 

Fig. 11. Fragment of a costal plate of a trionyx. From near Fort Bridger. Dr. Carter. 

Fig. 12. Fragment of a costal j)lat6 of a trionyx. From Little .Sandy Creek. Professor 
Hayden. 

Figs. 13-17. Glyptosaxjrus. All magnified two diameters. 

Figs. 13-15. Osseous dermal plates of the body. Figs. 16, 17. Plates of the head. From 
Grizzly Buttes. Dr. Carter. 

Figs. 18, 10. Oligosimus grand.evus : 

Fig. 18. Posterior view of a caudal vertebra. Fig. 19. Lateral view. Specimen obtained 
by Professor Hayden's party on Henry's Fork of Green Kiver. 



JJ. 8. GeologiGal Survey of the Territories 



Plate SVI 




T SINCHID 1 S.IV IITH PUII HO' 



1-6. ANOSTEIRA ORNATA 

7. ILnJM OF TURTLE 

8, 9 BAENA AREN03A 



10 ■'/t:rti _ :• •; . htle 
11, 12. ccstals of tfjontx 

lS-17 aLYPTOSAURUS. 



13, 19 OLIG-OSIMUS GRANDE VUS. 



EXPLANATION OF PLATE XVII. 



All tbo tigiires of tUo natural size, except Figs. 9, 10. 

Fig. 1. Clupea IIU5IILIS. From the original specimen obtained by Dr. John E. Evans, on Green River, 
in 1806. 

Fig. 2. Clupea alta. From the "Petrified Fish Cut," on the Union Pacific Railroad, near Green River. 

Fig. 3. Petalodus allegh-vniensis. Tooth, front view, from a specimen obtained by Messrs. Meek and 
Hayden, in the ni^iier carboniferous formation of Fort Riley, Kansas. 

Figs. 4-6. Cladodus occidentalis. Tooth found by Messrs. Meek and Hayden, in the upper coal 
measures of Manhattan, Kansas. 
Fig. 4. Back view. Fig. 5. Section of the crown. Fig. 6. Bottom of the root. . 

Figs. 7, 8. PTYcnoDUS occidentalis. Tooth discovered by Dr. John L. Le Coute, in the Cretaceous 
formation east of Fort Haj's, Kansas. 
Fig. 7. Upjier view. Fig. 8. Lateral view. 

Figs. 9, 10. XiPHACTiNUS AUDAX. A pectoral .spine, one-half the natural size. 
Fig. 9. Inferior view. Fig. 10. Superior view. 

Figs. 11-17. Myi.ocypeinds robustus. Pharyngeal bones, from Idaho, contained iu the collection of 

Professor J. S. Newberry. 
Fig. 11. Interior view of a left pharyngeal, containing the three intermediate teeth. 
Fig. 12. Inferior view of a right pharyngeal, containing the anterior three teeth. 
Fig. 13. Same view of a smaller left pharyngeal, with the posterior four teeth. 
Fig. 14. Similar view of another specimen, with the anterior three teeth and the bases of 

the posterior two teeth. 
Fig. 15. Posterior view of a right pharyngeal of an old auimal, with the second aud fourth 

teeth. 
Fig. 16. Inner view of a right pharyngeal, with the posterior four teeth. 
Fig. 17. Posterior view of the same siiecimen. 

Figs. 18, 19. Oncobatis pentagonus. Dermal plate, from the Pliocene of Sinker Creek, Idaho. 
Fig. 18. Upper view. Fig. 19. Lateral view. 

Fig. 20. Enchodus Shujiaedi. Dentary bone, natural size, but reversed iu position. From the Cre- 
taceous of Dakota. 

Figs. 21, 22. Cladocyclus occident^vlis. Two scales, natural size. Found with the preceding. 

Figs. 23, 24. Phasganodus dirus. From Cannonball River, Dakota. 
Fig. 23. A tooth of the natural size. 
Fig. 24. Dentary bone, reduced one-third. 

Fig. 25. Xystracantiius arcuatus. A dorsal spine, from Leavenworth, Kansas. 

Fig. 26. Hadrohy^u.s .suprbjius: 

The mutilated crown of an upper premolar tooth, natural size, seen on the triturating sur- 
face. From the Miocene Tertiary of Oregon. 



U S G-eoJo^Teal Survey ol" the Territ':>riefl 



flate XVll 




r s/»a A/ir * suff iiTH ph'l • 



EXPLANATION OF PLATE XVIII. 



All the figures are of the natural size except Figs. 51, 5'2. 

Figs. 1-14. Ptychodus MoitxoNl: 

Figs. 1, 2. Upper and posterior views of a large tootli from Kansas, obtained by Dr. George 

M. Sternberg. 
Figs. 3, 4. Upper and posterior views of auotber tootb, apparently from the same individual. 
Figs. 5, C. Upper and posterior views of another tooth from the same locality. 
Figs. 7, 8. Upper and posterior views of another tooth from the same locality. 
Figs. 9, 10. Upper and posterior views of another tooth from the same locality. 
Figs. 11, 12. Upper and anterior views of a large tooth from near Columbus, Mississippi, 

found by Dr. William Sinllman. 
Figs. 13, 14. Upper and posterior views of a tooth from Green County, Alabama, obtained 

by Professor Joseph Jones. 

Figs. 1.5-18. PTYCHonus occiDHNTA'Lis. Specimen obtained near Fort Hays, Kansas, by Dr. John L. 
Le Conte. 
Figs. 15, 16. Upper and posterior views of a worn tooth. 
Figs. 17, 18. Upper views of two small teeth. 

Figs. 19, 20. Ptychodus Whippleyi. The specimen obtained in the Cretaceous formation of Texas, by 
Dr. Benjamin F. Shiimard. 
Fig. 19. Upper view of a tooth. 
Fig. 20. Posterior view of the same tooth. 

Figs. 21-25. OXYRHINA EXTE.VTA : 

Figs. 21-23. Views, external or anterior, of three teeth from the Cretaceous formation of 

Kansas, obtained by Dr. George M. Sternberg. 
Figs. 24, 25. External v.iews of two teeth, from the Cretaceous formation near Columbus, 

Mississippi, obtained by Dr. William Spillman. 

Figs. 26-28. Otodus divaricatus. The specimen from Texas, probably from a Cretaceous formation. 
Loaned for examination by Dr. William Spillman. 
Fig. 2fi. External or anterior view of the tooth. 
Fig. 27. Lateral view reversed. 
Fig. 28. Internal or posterior view. 

Figs. 29-40. Galeocerdo falcatus. External views of teeth. 

Figs. 29-31. Specimens from the Cretaceous of Kansas, collected by Dr. George M. Sternberg. 
Figs. 32-36. Specimens from the Cretaceous, near Columbus, Mississippi, collected by Dr. 

William Spillman. 
Figs. 37-40. Specimens from the Cretaceous, near Fort Hays, Kansas, collected by Dr. John 

L. Lo Conte. 
Figs. 41, 42. Specimens from the Cretaceous of Texas, collected by Dr. Benjamin F. Shumard. 
Fig. 43. Specimen from the chalk of Sussex, England. 

Figs. 44, 45. Lamna : 

Fig. 44. External view of a tooth, from the Cretaceons, near Fort Hays, Kansas, found by Dr. 

John L. Le Conte. 
Fig. 45. External view of a similar but smaller tooth, from the chalk of Sussex, England. 

Figs. 4G-49. Lamna : 

Figs. 46, 47. Specimens from the Cretaceous of New Jersey. Fig. 46. Lateral view of a tooth. 
Fig. 47. E::terual view of another specimen. 

Figs. 48, 49. Specimens from the Cretaceous of Missisnppi, collected by Dr. William .Spill- 
man. Fig. id. Lateral view of a tooth. Fig. 4). External view of another tootli. 

Fig. .50. Outer view of a tooth. Specimen from the Cretaceous of Kansas, collected by Pro- 
fessor Hayden. 

Figs. 51, 52. Pal/EOSY<ops paludosos. Oue-half the natural si7,e. - 

Fig. 51. Side view of the face; from the same specimen as the teeth of Fig. 3, Plate IV. 
Fig. 52. Lower jaw; repeated from the same specimen as Fig. 11, Plate V. 



U. S, geological Survey of the Territories 



Plate XSnil. 



''■■■''^^'i'0^. 




ThoK. SmcLuric Soa,.lJftx.Flula. 



EXPLANATION OF PLATE XIX. 



Figs. 1-4. PaLvEOSYOPS rAi.uDosu.s. All half size except Fig. 4. 
Fig. 1. Front view of the left femur. 
Fig. 2. Lower extremity of the right femur. 
Fig. 3. Distal extremity of the right humerus. 
Fig. 4. The right patella, luuer view, natural size. Lodge-pole tr.ail. Dr. Carter. 

Fig. 5. Hyrachyus. Au astragalus. Natural size. 

Fig. 6. Distal extremity of left femur of Testudo niol/rarensis, one-half the natural size. 

Fig. 7. Distal extremity of right humerus of Testudo nebmscensis, from a young animal, half the natural 
size. 

Fig. 8. Distal extremity of the right humerus of Testudo nioirarensis, half the natural size. 

Fig. 9. Portion of a carapace of Tesludo nehrascensis, internal surface exhibitiug the ridge of attachment 
of the neural sijines and the narrow costal cajjitula, natural size. 

Fig. 10. Portion of right scapula of Testudo neJirascciisis, hack view, one-half the natural size. 

Fig. 11. Sacral vertebrae of Clustcrnoit undatum, inferior view, natural size. 

Fig. 12. Lateral view of the same. 

Fig. 13. Ungual phalanx of an undetermined reptile, one-half the natural size. See page 285. 

Fig. 14. Dermal plate of Ti/losteus ornatus, one-half the natural size. 

Figs. 15, 16. Pycnodus faba. Natural size. 

Fig. 15. Portion of a left ramus of the lower jaw, with teeth. The specimen from the Creta- 
ceous formation of Mississijipi, 
Fig. 16. Fragment of the left ramus of the lower jaw, with three teeth, from the greensand 
of Crosswicks, Burlington County, New Jersey. 

Figs. 17-20. Hadrodus priscus, natural size. Specimen belonging to Dr. William Spillman, of Colum- 
bus, Mississippi, and found by him in the cretaceous formation of that State. 

Fig. 17. Front view of a supposed premaxillary bono, with two teeth. 

Fig. 18. Posterior view of the same, exhibiting at the sides the two reserve cavities for suc- 
cessioual teeth. 

Fig. ID. Lateral view. 

Fig. 20. Inferior view. 

Figs. 21, 22. EuMY'LODUS LAQUEATUS. Mandible two-thirds natural size. From the Cretaceous forma- 
tion of Mississippi, discovered by Dr. William Spillman. 
Fig. 21. Inner view ; specimen reversed. 
Fig. 22. View of the upper or triturating surface, with the inner surface in xjcrspective. 



XJ. S. G.eological Su^'vey of the Territories 



Plate X:XX. 




rhoB, Sinclair ieSoa. lith.Phila. 



EXPLANATION OF PLATE XX. 



Fig. 1-7. Paljeosyops paludosus. Figures one-lialf size. 

Fig. 1. Tibia of tbe right side, front view. From Grizzly Bnttos. Haydon's collection 

of 1870. 
Fig. 2. Calcanonm, upper view. Fount! by Dr. Corson on Smitb's Fork of Greeu River. 
Fig. 3. Astr.^galus, upper view. Found by Dr. Carter near Miller.sville. 
Fig. 4. Cuboid, scaphoid, and osternal cuueiform. From Chnrch Buttes. Haytlcn's collection. 
Fig. 5. Metatarsal. Found by Dr. Corsou near Fort Bridger. 
Fig. 6. First phalanx. Found by Dr. Carter ou Henry's Fork of Green River. 
Fig. 7. Second phalanx. Found by Dr. Carter near Fort Bridger. 

Fig. 8. PAL.E0SYOPS MAJOR : 

Portion of the right ramus of a lower jaw, one-half size. The specimen is somewhat swollen 
and altered in character from disease, and is one of those ui^on which the sjiecies was first 
indicated. Discovered by Dr. Carter at Grizzly Buttes. 

Figs. 9-11. MERYCOCHOiRUS RU.STICUS. Natural size. From Hayden's collection of the Sweetwater 
River. 

Fig. 9. Lower extremity of the right tibia, front view. 
Fig. 10. Astragalus of the right side, upper view. 
Fig. 11. Calcaueum of the right side, upper view. 

Fig. 12. Merycochcerus(?) Natural size. 

Lower end of the right tibia of a smaller species than the preceding, with the specimens of 
which it was found. • 

Fig. 13. Hipparion(?) Natural size. 

Eight cuneiform bone, ujiper view,*of a small equine animal. Specimen found with the 

remains of Merycochaerus just indicated. 
Figs. 14-22. Remains from Texas, submitted to examination l>y Professor S. B. Buckley. 

All of the natural size. 

Fig. 14. HlPPARipN SPECIOSUM (?) 

Last upper molar of the right side ; view of the triturating surface. From Washington 
County. 

Fig. 15. HipPARiON (f) 

A third or fourth upper molar of the left side. Found witli the preceding specimen. 

Fig. 16. Protoiiippu.s perditus (?) 

A second or third upper molar of the right side. From Independence, Washington County. 

Figs. 17, 18. PRbTOHIPPUS PLACIDUS(?) 

Fig. 17. A third or fourth upper molar of the right side. Found in association with the 

specimens of Figs. 14, 15. 
Fig. 18. A first upper molar of the right side, probably of the same species as the former. 

From Bastrop County. 

Fig. 19. ANCiiiTriERiUM('?) australe: 

First upper molar of the right side. Found in association with the specimen of Fig. Ifi. 

FFg. 20. Protohippos : 

A lower molar of the riglit side. From Navarro County. 



PLATE XX. 



Fig. 21. Procamelus (?) 

A first or second upper molar of tho left side, view of thi; triturating surface. Specimen 
found iu associatiou with those of Fig. 14, 1.5, aud 17, in Washiugtou Couuty. 

Fig. 22. Astragalus of tho left side, upper view, probably of the same species as the last, and found 
with it. 

Fig. 23. HlPPAI!ION(?) I'AUVIILUS 

A coronary boue, or second phalanx, of the natural size. Fonnd at Antelope, Nebraska. 

Fig. 24. FeLIS AUGUSTUS ? 

Distal extremity of the right humerus, front view, one-half size. Specimen found on tho 
Niobrara River, by Professor Hayden. , 

Figs. 25, £6. Hyraciivus aguarius. From a specimen obtained by Dr. Carter at Grizzly Buttes. 
Natural size. 

Fig. 25. Left ramus of tho lower jaw, containing the back two premolars and the two suc- 
ceeding molars. 

Fig. 26. View of the triturating surface of the same teeth, with the addition of part of the 
second premolar. 



n. S. Geci.igical Surtey of the I'trritones 



"Plab- XX 




Tho «. S incloir & Son , Uth . Phila . 



EXPLANATION OF PLATE XXI. 



Figs. 1-4. M.\STODON OBSCURDS: 

Last lower molar of the left side, natural size. Specimen discovered by Dr. Lorenzo G- 
Yates, in Contra Costa County, California, and now in the museum of Amherst College. 

Fig. 1. View of the triturating surface. 

Fig. 2. Outer view*f the same sjiecimen. 

Fig. 3. Fragment of a tusk, two-thirds the natural size, exhibiting the broad band of enamel 
indicated by the darljer shade. Specimen found by Dr. Yates in Stanislaus County, Cal- 
ifornia, and belonging to Amherst CoUege museum. 

Fig. 4. Outline of the transverse section from, the smaller end of the same specimen, of the 
natural size. 



U. S (;»>oloyioal Survey of thp I'erriLotiuo. 



PlateXXI 





:,p. 





-^■-■■.^^'■'^^■?-^«a>«^"'-.'-' -!;r^i 




SIMCLAiH * SO 



1 t. MASTODON, CONTRA COSTA COijN"^Y, CAl. | ,3,4 MASTODON, STANISLAUS COUNTY, CAL, 



EXPLANATION OF PLATE XXII. 



Fig. 1-4. Mastodon obscurus: 

Fragments of a lower jaw, from near Santa F6, New Mexico, presented to the Smithsonian 
Institution by W. F. M. Arny. 

Fig. 1. Portion of the jaw containing the greater part of the last molar tooth. Fig. 2. Por- 
tion of the symphysis. The two fragments placed in their relative position, and reduced 
to one-sixth the natural size. 

Fij;. 3. Inferior view of the symphysial fragment, exhibiting exposed portions of the incis- 
ors. One-fourth the natural size. 

Fig 4. The last inferior molar, uatur.il size, seen on the triturating surface. The back i)or- 
tion, consisting of another division and the heel, are broken away. 

Figs. 5, 6. Mastodon AMEin.CANUS. Au anomalous molar tooth, natural size. 
Fig. 5. View of the triturating surface. 
Fig. G. Side view. 

Fig. 7. GitAPHiODON viNKAitius. A tooth of the natural size. Specimen from the Miocene of Slartha's 
Vineyard, belonging to the museum of the Smithsonian Institution. 



T7. S. GeoloHK^al Survey oT the Temt«ne« 



Plate ZXII. 





r\y 





m 





"3" ^1 



* w m 



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T*>V 



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ThoK. .SinddirJb >bil. JitlL.Ftula.. 



EXPLANATION OF PLATE XXIII. 



All the figures of the iiatui'al size except Fii;. 16, which is one-half size. 

Figs. 1, 2. PALiEOSYOPS MAJOR : 

Fig. 1. The complete series of molar teeth of the left side of the lower jaw, except the drst 

premolar. The second and tliird premolars are reversed from those of the opposite side. 

Specimen discovered hy Dr. Carter in Dry Creek Canon, forty miles from Fort Bridger. 
Fig. 2. A series consisting of the molars and last two premolars contained in detached 

fragments of a lower jaw. Specimens obtained by Dr. Carter ou Dry Creek. Tlie molars 

are larger and more worn than in the preceding specimen. 

Figs. 3-6. Pai-.s;osyops paludosus. ' Specimens ui>on which the species was originally established. 
Hayden's collection of 1870. 
Fig. 3. A third lower premolar of the left side. 
Fig. 4. A last lower premolar of the right side. 
Fig. .5. A first lower molar of the left side. 
Fig. 6. Anterior part of a second upper molar of the left side. 

Figs. 7-11. Pal^eosyops ma.iok. Specimens found by Dr. Corson in Dry Creek Cauon. 
Fig. 7. The left upper canine tooth. 
Fig. 8. The second upper premolar of the left side. 
Fig. 9. The last upper premolar of the same side. 
Fig. 10. The second npjier molar of the same side. 
Fig. 11. The last upper molar of the same side. 

Fig. 12. Pal^osyops major : 

Series of premolars from the second to the last, inclusive, of the right side. From Dry 
Creek. Dr. Carter. 

Fig. 13. Pai..«:osyops (Limnohyus) i.aticeps(?) 

A second upper molar of the right side. A comparatively smooth tooth. Specimen discov- 
ered by Dr. Corson, in association with the large canine tooth of Figs. 1-3, Plate XXV. 

Figs. 14-10. Pal^osyoes majok: 

Fig. 14. A last lower molar of the right side. Contained in a jaw fragment obtained by 

Dr. Carter at Dry Creek Canon. 
Fig. 15. An inferior incisor, lateral view, belonging to the same individual as the specimens 

of Figs. 7-11. 
Fig. 16. Upper view of a cranium, one-half the natural size. The specimen discovered by 

Dr. Carter at Dry Creek Canon. 



U. S. G.eDlogical Surrey of the Tern ton 



Plate XXai, 






PALAEOSYOPS. 



IhoK SiiirldtrJc San. lith.Pliila. 



EXPLANATION OF PLATE XXIV. 



Figs. 1-5. Pal^osyops major : 

Fig. 1. View of a left side of a ccauium, oue-lialf the natural size. Specimen discovered by 
Dr. Carter on the bnttes of Dry Creek Canon. 

Fig. 2. View of the left side of a crushed facial specimen, one-half the natural size. Speci- 
men found by a Shoshone Indian, and brought to Dr. Carter. 

Fig. 3. View of the triturating surfixce of a penultimate upper molar of the riglit side, 
natural size. From the same skull as Fig. 1. 

Fig. 4. Portion of the right ramus of the lower jaw of the same animal, one-half the natural 
size. 

Fig. .5. Au upper lateral incisor, natural size. Specimen found by Dr. Corson in the buttes 
of Dry Creek Canon. 

Figs. 6, 7. Pal^osyops paludosus (?) Natural size. 

Fig. 0. Fore part of the upper jaw, containing the first three premolars and part of the fang 

of the caniuft. 
Fig. 7. Triturating surfaces of the premolars. 

Fig. 8. Paljeo-Syops humilis : 

A last upper molar of the left side, natural size. Found by Dr. Corson on the buttes of Dry 
Creek Canon. 



;. a G;eoJogieal Survey ol' lLo IViritories 



Plate XXTV. 






ThV SiHcUjr * SoB.PinJa. 



PAL AEO STOPS. 



EXPLANATION OF PLATE XXV. 



UiNTATiiEniCM ROBUSTUM. All the Specimens discovered by Drs. Corson and Carter at Dry 
Creek Canon. Natural size, excei)t Figs. 8 and 11, which are one-half size. 

Figs. 1-5. A supposed upper canine tooth. Discovered by Dr. Corson in comj)any with a fragment of the 
same tooth of the other side, the specimen reprcsente<l in Figs. 13, 14, and the molar of 
Palajosyops represented in Fig. 13, Plate XXIII. Originally referred to a supposed car- 
nivore, with the name of Uiniamastix atrox. 

Fig. 1. Outer view of the right canine. The restored outline of the lance-head-like point 
is, perhaps, a little exaggerated. 

Fig. 2. Inner view of the point of the same specimen. 

Fig. 3. Front view. 

Fig. 4. Outline of a transverse section of the lance-head-'like point. 

Fig. 5. Outline of a section near tho base of the specimen. 

Figs. 6-12. Specimens found together, with portions of the skull and other boues of the skeletou, ten 
miles distant from the former. Discovered by Drs. Carter and Corson. 
Fig. 6. Inner view of tho last upper molar of the right side. 
Fig. 7. View of the triturating surface of the same tooth. 

Fig. 8. Outer view of the same tooth inserted in a jaw-fragment, half the natural size. 
Fig. 9. Inner view of the last lower molar of the right side. 
Fig. 10. View of the triturating surface of the same tooth. 
Fig. 11. Outer view of the lower-jaw fragment, containing tho same tooth, one-half tho 

natural size. 
Fig. 12. Triturating surface, much worn, of the first upper molar, of tho right side. 

Figs. 13, 14. A supposed upper jiremolar of the same animal. Discovered by Dr. Corson in company with 
the large canine tooth of Figs. 1-5. 
Fig. 13. Inner view of the tooth. 
Fig. 14. Triturating surface. 



V S ^eol'JbT-cal burveT' uT t}it; Ten;' 



Plate >;XY. 




UINTATHERIUM 



Tho«.Sl,..l.„ri<S..n-l.lk.Pli>>a. 



EXPLANATION OF PLATE XXVI. 



Figs. 1-8. UlNTATHERIDJI ItOBUSXUM : 

Fig. 1. "View of the right side of a mutilated cranium, one-half the diameter of nature. Spec- 
imen upon which the genus was characterized. Discovered by Dr. Carter about fifty miles 
from Fort Bridger. 

Fig. 2. An atlas, of the same species. Inferior view, one-fourth the diameter. 

Fig. 3. A right humerus. Found by Dr. Carter in the same locality as the specimen of Fig. 1. 
Anterior view, one-fourth the diameter. 

Fig. 4. Proximal extremity of a femur, probably pertaining to a larger species of the same 
genus, or perhaps to a larger variety. One-fourth the diameter. 

Fig. 5. Distal extremity of another femur, probably of U. robustmn. One-fourth the diameter. 

Fig. 6. Calcaneum of the left side. Upjier view, one-half size. 

Figs. 7, 8. Astragalus, one-half size. 

Fig. 7. Upper view. Fig. 8. Inferior view. 

Figs. 9, 10. Hyrachyus EXinnus : 

Left lower iienultimate molar tooth, natural size. 

Fig. 9. Outer view. Fig. 10. Upper view. 

« 

Fig. 11. Hyrachyus nano.s : 

Right ramus of the lower jaw, retaining the back four molar teeth. Natural size. 



tf. 'S. Geological Survey of the Territories 



Plate XXVT 




■ni" sir.cUirftSon.Piiila. 



1-8 UINTATHERIUM. 9-11 HYRACHYUS . 



EXPLANATION OF PLATE XXVII. 



Figs. 1, 2. HiPPOSYUS FOIiMOSUS : 

Au upper luolar tootb, probably tbo seoouil true molar of tbo loft sido, maguified tbroe 

diameters. 
Fig. 1. Outer view of the crown. 
Fig. 2. View of the triturating surface. 

Figs. 3, 4. Wash.\kius insignis : 

Fig. 3. Portion of tbo rigbt ramus of tbo lower jaw, containing tbo last two molars, magni- 
fied three diameters. 
Fig. 4. View of tbo triturating surfaces of the teeth, magnified eight diameters. 

Fig. 5. HYOP.SODUS MINUSCULOS : 

View of tbo triturating surfaces of the last premolar and the molars of the left side, m.agni- 
fied four diameters. 

Figs. G-10. UixTACyoN edax : 

Fig. C. Right side of the lower jaw, containing the intermediate three premolars, part of the 
first molar, and the second molar, natural size. 

Figs. 7-10. The teeth, magnified three diameters. 

Fig. 7. Triturating surface of tbo second molar. 
Fig. 8. Outer view of the same tooth. 
Fig. 9. Upper view of the premolars. 
Fig. 10. Outer view of the same. 

Figs. 1 1-13. UlNTACYON VORAX : 

Fig. 11. Fragment of the left side of the lower jaw, containing part of the first molar and 

the second molar, natural size. 
Fig. 12. lTi>per view of the secoud molar. 
Fig. 13. Oater view of the second molar. 

Figs. 14, 15. Mysops featernus : 

Fig. 14. Eight side of lower jaw, with tbo last three molars, maguified two diameters. 
Fig. 15. View of the triturating surfaces of tbo molars, magnified eight diameters. 

Figs. 16-18. Paramys delicatior : 

Fig. 16. Lower molar of the rigbt side, the second or third of tbo series, seen on tbo tritu- 
rating surface, magnified three diameters. 

Fig. 17. U[)per molars of the same animal, ajipareutly the intorraediatc pair. Outer view, 
magnified three diameters. 

Fig. 18. View of the triturating surfaces of the same teeth, maguified three diametens. 

Figs. 19, 20. MiCROSY'OPS (?) 

An upper molar tooth, magnified four times. 

Fig. 19. Outer view. 

Fig. 20. View of the triturating surface. 

Figs. 21, 22. Hyraciiyus nanus (?) 

A last upper premolar, magnified two diameters. 

Fig. 21. Outer view. 

Fig. 22. View of the triturating surface. 



PLATE XXVII. 



Fig. 23. Fragment of tbo left side of the lower jaw, coutainiug two premolars, apparently the third and 
fourth, of au undetermined carnivore, natural size. From the Bridger Eocene of Wyo- 
ming. 

Figs. 24, 25. Megalomeryx niobrarensisC?) A lower molar tooth, natural size. From the Tertiary of 
L'Eau qui Court County, Nebraska. Sjiecimeu in the museuin of Swarthmore College. 

Fig. 24. Triturating surface. 
Fig. 25. Outer view. 

Figs. 26-29. PROCA.MELUS viRGiNiENSis. Natural size. Specimens from the Miocene of Virginia, and 
belonging to Mr. C. M. Smith, of Richmond, Virginia. 
Fig. 26. Outer view of the last lower molar of the right side. 
Fig. 27. Triturating surface of the same. 

Fig. 28. The last premolar and first molar of the right side, outer view. 
Fig. 29. Triturating surfaces of the same. 

Figs. 30-34. Uesitatherium robostcm : 

Fig. 30. Last upper molar of the right side, (juter view, natural size. 

Fig. 31. Last lower molar of the right side, outer view, natural size. 

Fig. 32. Portiou of the left ramus of the lower jaw, one-half the natural size. . Fig. 33. Mu- 
tilated corouoid and condyle of the same specimen as the former. 

Fig. 34. Upper view of the atlas, from the same specimen as Fig. 2, Plate XXVI, one-fourth 
the diameter of nature. 

Fig. 35. Saniwa ensidens. Tooth magnified eight diameters. 

Figs. 36,37. Saniwa major: 

Two dorsal vertebra?, natural size. 
Fig. 36. Inferior view. 
Fig. 37. View of right side. 

Figs. 38, 39. Chameleo pristin0S. Fragment of the lower jaw, magnified three diameters. 

Fig. 36. Outer view. 

Fig. 39. Inner view. 

Fig. 40. Undetermined tooth of a reptile, magnified two diameters. From the Bridger 
Eocene formation of Wyoming. It may be the tooth of a crocodile or a lacertian. It is 
an isolated specimen, partially imbedded in a greenish sandstone, with fresh-water shells. 
The crown is compressed mammillary, and strongly striate, from an acute-bordered summit. 



n. S. Geological Survey of the Territories 



Plate XXVU. 










d^^ 




liiV Sinclair tSon,Eltfla 



EXPLANATION OF PLATE XXVIII. 



Figs. 1, 2. UlNTATHEUIUM KOBUSTOM : 

Fig. 1. Outline talieu from Professor Marsh's Fig. 1, Plate II, of Dinoceras mirahilis, iu the 
Am. Jour. Science, 1873, enlarged so as to accord with one-sixth of the size of the frag- 
ments introduced iu the figure, which corresi^ond with those of Figs. 1 and 8, Plate XXV, 
and Fig. 1, Plate XXVI. 

Kg. 2. View of the base of the cranial specimen also represented in Fig. 1, Plate XXVI. 
One-sixth the diameter of nature. 

Fig. 3. Large osseous i>rotuberance, one-half the size of nature, resembling the similar 
osseous protuberances of the specimen of Megaccrops, represented in Figs. 2, 3, Plate 1. 
The specimen is from the Mauvaises Terres of White River, Dakota, and was originally 
suspected to belong to Titanotherium. 

Figs. 4-8. Bison latifrons: 

Figs. 4, 5. Cranium from Pilarcitos Valley, California, discovered by Messrs. Calvin and 
Wilfred Brown, and presented to the Academy of Natural Sciences of Philadeli^hia. One- 
fifth the natur.al size. 

Fig. 4. Upper view. Fig. 5. Posterior view. 

Figs. 6, 7. The second and last npper molars seen on their triturating surfaces. Natural size. 
Specimens from California, belonging to Wabash College, Indiana. 

Fig. 8. An upper second molar of the left side, considerably worn, and seen on its triturat- 
ing surface. Natural size. From Luzerue County, Pennsylvania. 

Fig. 9. Mastodon americanxjs: 

A first lower premolar of the right side, natural size. Found with the iirecediug. 



rr S. Geological Survey of the Temtones. 



Plate XXVm 



/ 



g^,. 




^^;'' 


V-~i..rr.r-. 


fW 


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m 








Ai 



Wt'-.!- 




Ih? SmcUul it Soi\ iith . flu la . 



EXPLANATION OF PLATE XXIX. 



All the figures one-balf the natural size. 

Fig. 1. TkIOXYX UlNTitENSIS : 

The nearly entire carapace or upper shield, partially represented. Specimen discovered by 
Major Kobert S. La Motte, in the buttes of Dry Creek, ten miles from Fort Bridger, and 
presented by him to the Academy of Natural Sciences of Philadelphia. 

Figs. 2-4. Testudo Uoksoni: 

Specimens discovered by Dr. Joseph K. Corson, in association with portions of the plastron, 

and the specimen of the carapace represented in Fig. 1, Plate XXX. 
Fig. 2. Anterior view of the proximal extremity of the right humerus. 
Fig. 3. Outer view of the same specimen. 
Fig. 4. Distal extremity of the right femur, front view. 

Fig. 5. Paljeosyops paludosus: 

Femur of the left side, anterior view. Specimen obtained by Dr. Carter on Grizzly Buttes. 



U.S. CeologicalSurveTof il'.^ Terntori.e.'! 



Plate XXK. 








fetiiii^ l'^ ' ^ ^' 





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V , ^ 







A .9 





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Til*' SincUir fcSsn.PhTi 



iTRlONYXUlNTAENSrS. 2^4TESTUD0 CORSONI . 5.PAIJ\K0SYOHS PALUDOSUS- 



EXPLANATION OF PLATE XXX. 



Figs. 1-4. Testudo Coksoni : 

Fig. 1. Intermeilinte portion of tbo carapace, one-half the natural size, exhibit-inn; the series 
of vertebral jilates, from the first to the eighth and part of the ninth, and contiguous por- 
tions of the costal plates. Specimen cliscovered by Dr. Joseph K. Corson on the buttes of 
Dry Creek, and jux'sented hy him to the Academy of Philadelphia. 

Fig. 2. Plastron, or lower shield, one-third the natural size. Specimen discovered by Dr. 
Corson ou Grizzly Buttes, and presented to the Academy. 

Fig. 3. Anterior i)rocess of another plastron, one-half the natural size. From a specimen 
discovered by Dr. Corson in the same locality as the last. 

Fig. 4. Anterior process of a nearly complete plastron, one-half the natural size. From a 
specimen discovered by Mrs. Dr. Carter on the buttes of Dry Creek, and presented by her 
to the Academy of Philadelphia. 

I'ig. 5. CLADOCYCLUS OCCIDENT^iXlS : 

Large scale, imbedded in a lead-colored calcareous shale, natural size. Specimen obtained 
by Professor Hayden from the Cretaceous formation of Sage Creek, Dakota. 



U S Geological S uivey of the Terrilories 



Plate XXX. 




IV; Sircliui 4 Soo.PlDJa. 



1-4 TESTUDO CORSONI. 



5. CLADOCYCLUS. 



EXPLANATION OF PLATE XXXL 



Fig. 1. Eestorecl skull of PaJocosyops. The cranium ami face arc introduced from the specimens of 
Figs. 1, 2, Plate XXIV, and Fig. 51, Plate XVIII; and the lower jaw from the specimen of 
Fig. 52 of the latter plate, and Fig. 4, Plate XXIV. About half the natural size of the 
skull of P. paludosus. 

Fig. 2. Canis indlvnensis : 

Right ramus of the lower jaw, one-half the natural size. Specimen from San Leaudro, Cali- 
fornia. Discovered by Dr. Lorenzo G. Yates, and now in the museum of Wabash College, 
Crawfordsville, Indiana. 

Fig. 3. FeLIS IMPBRIALIS : 

Fore part of the upper jaw, with the second premolar, one-half the natural size. Accom- 
panying the preceding specimen. 

Fig. 4. LuTRA pisciNjVRia: 

Tibia of the right side, two-thirds the natural size. From Sinker Creek, Idaho, and belong- 
ing to the Smithsonian Institution. 



'Z . S- G.eoJogical SurvsY of the Terntonee 



Plate XXXI . 




Th'» aiidaii & Son. liUi . Phila 



EXPLANATION OF PLATE XXXII. 



All tbc figures of the natural size. 

Figs. 1-G. Ajiia (Pcotamia) uintaensis: 

Fig. 1. Centrum of .1 dorsal vertebra, auterior view. Fig. 2. View of the same beneath. 

From Dry Creek Canon. 
Fig. 3. Centrnra of an atlas, auterior view. Fig. 4. Inferior view of the same. From Dry 

Creek Cauou. 
Fig. 5. A series of three posterior dorsal centra, inferior view. From Dry Creek Canon. 
Fig. 6. Basi occipital, posterior view. Fig. fia. Inferior view of the same. From Dry Creek. 

Figs. 7-11. Amia (Pkotamia) media : 

Fig. 7. Centrum of a dorsal vertebra, upper view. Fig. 8. Posterior view. Fig. 9. fcferior 

view. Junction of Sandy and Green Elvers. 
Fig. 10. Centrum of a posterior dorsal vertebra, back view. Fig. 11. Inferior view. Dry 

Creek. 

Figs. 18, 13. Lepidosteus notabilis: 

Fig. 12. Centrum of a dorsal vertebra, inferior view. Fig. 13. Posterior view. From near 
Washakie, Wj-oming. 

Figs. 14, 15. Lepidosteus atkox : 

Fig. 14. Centrum of an auterior dorsal vertebra, inferior view. Fig. 15. Posterior view. 
From the junction of Big Sandy and Green Rivers. 

Figs. 16, 17. Lepidosteus (?) See page 190. 

Fig. 16. Centrum of a posterior dorsal vertebra, seen beneath. 
Fig. 17. Posterior view of the same.' 

Fig. 18. Lepidosteus simplex: 

The basi.occipital and three vertebral centra, scon beneath. From near Washakie Station, 
Wyoming. 

Figs. 19-22. Hypamia elegans. A vertebral centrum. From Dry Creek. 

Fig. 19. Upper view. Fig. 20. Lateral view. Fig. 21. Posterior view. Fig. 22. Inferior 

view. 

Figs. 23,24. Amia (Protamia) cnAClLis. A centrum from near tho middle of the dorSl scries. Henry's 
Fork of Green Elver, Wyoming. 
Fig. 23. Posterior view. Fig. 24. Inferior view. 

Fig. 25. Lepidosteus (?) 

Fragment of the right dentary bone. See jiage 190. 

Fig. 26. Lepidosteus simplex. A tooth. See page 191. 

Figs. 27-30. Lepidosteus (?) Scales from Big Sandy and Green Eivor. 

Figs. 31-34. Lepidosteus simplex. Scales. From near Washakie Station. See page 191. 

Figs. 35-38. Lepidosteus. Scales. Little Sandy Creek. See page 192. 

Figs. 39-42. Lepidosteus. Scales. Near Fort Bridger. 

Fig. 43. Lepidosteus. Scah^. Sco page 192. 



PLATE XXXII. 



Figs. 44-4G. PlMELODU.S ANTIQUUS: 

Figs. 44, 45. Fragments of iieotoral spines. 

Fig. 4G. Portion of a dentary bone, seen from bouoath. 

Figs. 47-51. Phaeeodus acutus. Jaw fragments, from the junction of Big Sandy and Green Rivers, 
Wyoming. 
Fig. 47. Portion of tlie right xiremaxillary. 
Fig. 48. Portion of left jiremaxillary. 
Fig. 49. Portion of right dentary. 
• Fig. 50. Portion of left dentary. 

Fig. 51. Portion of a maxillary. 

.Figs. 52, 53. Trygon (?). Caudal spine of a Eay, From the Miocene of Virginia. Fig. 52. Anterior view 
of basal portion of the spine. Fig. 53. Section of the same. Belonging to Mr. C. M. Smith. 

Figs. 54, 55. Myliobates (?). Caudal spine. Found with the preceding. 
Fig. 54. Anterior face of basal portion. 
Fig. 55. Section of the same. 

Figs. 56, 57. Pkotautoga conidens : 

Portions of premaxillaries, with tooth, from tbc Miocene of Virginia. Belonging to C. M. 

Smith. 
Fig. 56. Fragment of the left prcmaxillary, eoutaiuiug the lirst tooth. 
Fig. 57. Right premaxillary, inner view, exhibiting, besides the outer row of large teeth, an 

inner row of small ones. 

Fig. 58. ACIPfiNSER ORNATUS: 

A dermal plate. From the Miocene of Virginia. Belonging to Mr. C. M. Smith. 

Fig. 59. AsTERjiCjUStTIIUS SIDERIUS: 

Basal portion of an ichthyodorulite, lateral view. 



TJ. S Geological Survey of the Territories. 



Plate XXXE - 





<1-hi 



, «11M;1 



ii%Mii 












mi' 



'/ 



'TF 






56 



r-'0^ 



59 




y J> 



ill'.* jinclsdr ISon. PHl^. 



EXPLANATION OF PLATE XXXIII. 



All the figures of tho uatiiial size. 

Figs. 1, 2. Equus occidentalis : 

Fig. 1. The anterior four upper molars of the left side, seen on their triturating surfaces. 

The teeth are contained in a jaw-fragment, obtained by Dr. George H. Horn from an 

asphaltum deposit near Bueua Vista Lake, California.. Specimen in the museum of the 

Academy of Philadelphia. 
Fig. 2. A second upper left molar, seen on the triturating surface. From Tuolumne County 

California. 

Figs. 3-18. Equus major: 

Figs. 3, 4. A first upper molar tooth of the right side. Fig. 3. Outer view. Fig. 4. Tritu- 
rating surface. Specimen from Hardin County, Texas. 

Figs. 5, 6. A first upper molar of the right side. Fig. 5. Outer view. Fig. 6. Triturating 
surface. From Illinois Blufl's, Missouri. 

Figs. 7, 8. A last upper molar of the right side. Fig. 7. Outer view. Fig. 8. Triturating 
surface. From Hardin County, Texas. 

Fig. 9. A last lower molar of the left side, view of the triturating surface. Found with the 
last. 

Fig. 10. A fifth lower molar of the left side, triturating surface. Found with the last. 

Fig. 11. A second or third upper molar of the right side, triturating surface. From Galves- 
ton Bay, Texas. Presented to the Academy by Dr. Tbomas H. Streets. 

Fig. 12. A first lower temporary molar, triturating surface. From Hardin County, Texas. 

Fig. 13. An upper last temporary molar of the left side. Found with the last. 

Fig. 14. An upper second or third molar of the left side. From the "phospbate beds" of 
Ashley Eiver, South Carolina. 

Fig. 15. A second or third lower molar of the right side. From the same locality as the last. 

Fig. 16. An upper second or third molar of tho right side. From Luzerne County, Pennsyl- 
vania. 

Fig. 17. A second lower moUir of the left side. Found with the last. 

Fig. 18. An upper fourth or fifth molar of tlie left side. From Texas. 

Fig. 19. Equus. Portion of an upper molar of the left side of an undetermined species. From the lignite 
beds of Shoalwater Bay, Washington Territory. , 

Figs. 20, 21. Two phalanges of undetermined animals, both fuund, in association with the equine and 
other remains, in an asphaltum deposit in Hardin County, Texas. They are both satu- 
rated with bitumen. Fig. 20. Lateral view of the specimen. Fig. 21. Inferior view of 
the second specimen. 



U. S. ^trolo^.oal Siirvpy cf the TerritoTiei* 



Plate xxxnr. 




Th" Sindaii i Son, lith . Phila 



EXPLANATION OF PLATE XXXIV. 



All the figures two-thirds the size of nature except Figs. 12-22, wliicli are of the uatural 
size. 

Figs. 1 to .5 and 10. Clid.vstes iNTERMEDins. From the Cretaceous of Alabama. Museum of the Acad- 
emy of Natural Sciences. 

Fig. 1. Outer view of the fore part of the left mandible. 

Fig. 2. Back part of the right inaudible, outer view reversed. 

Fig. 4. Reserve tooth, concealed in the excavated base of the last of the series in the speci- 
men of Fig. 1, seen from within. 

Fig. 5. Reserve tooth, concealed in the excavated base of the second of the series of the same 
specimen, seen from within. 

Figs. G to 9 and 11. Clidastes affinis. From the Smoky HiU Eiver, of Kansas. Belonging to the mu- 
seum of the Smithsonian Institution. 
Fig. 6. Outer view of the left mandible. 

Fig. 7. Inner view of back part of the right mandible, exhibiting the glenoid articulation. 
Fig. 8. Upper view of two fragments of the cranium. 
Fig. 9. The basi-spheugid bone. 

Fig. 10. C. Intekmedids. The axis seen below and with the fore part downward. 

Fig. 11. C. AFFINIS. The left humerus, posterior view. 

Fig. 12. Lestosaurus coryph^us: 

Greater portion of a palate-bone, with teeth, natural size. From the Smoky Hill Eiver, 
Kansas. 

Fig. 13. CuDASTES AFFINIS. Tooth contained withiii a jaw-fragiueut. From Smoky Hill Eiver, Kansas. 

Fig. 14. Crown of a similar tooth. From L'Eau qui Court Countj', Nebraska. It is compressed, conical, 
curved, with acute borders and smooth surfaces. Fig. 15. Section of the same tooth. 

Figs. lG-22. Teeth of mosasauroids, natural size, together with the iireceding specimen from L'Eau qui 
Court County, Nebraska. Presented to Swarthmore College by George S. Truman. 

Fig. 16. Crown of a shed tooth, with striated enamel. Fig. 17. Triinsverse section of the 
same, at the base. 

Fig. 18. Shed crown of a largo tooth, with'striatcd enamel, anterior view. 

Fig. 19. Shed crown of a tooth, with distinct subdivisioual jilaues. Fig. 20. Outlhics of sec- 
tions of the same at the base and above the base. 

Fig. 21. Crown of another shed tooth, intermediate in character with the two jjreoeding. 
Fig. 22. Outline of a section of the same at the base.. 



U- S. G;eolosical Survey of the Terntonea 



Plate XKXIV. 




I 



ThI'ShickuiS.San hth.ri:i 



EXPLANATION OF PLATE XXXV. 



All tho figures oue-lialf the uatural size except Fig. 14, which is of the natural size. 

Figs. 1-11. Tylosaurus dyspblor. • Specimens from the Cretaceous of New Mexico, and helonging to 
the Smithsonian Institution. 

Fig. 1. Ai'ticular ball of a posterior dorsal centrum. 

Fig. 2, 3. Tho same of two other specimens, exhibiting a successive increase of compression 

from above downward. 
Fig. 4. Articular ball of a caudal centrum. 
Fig. 5. Left lateral view of the same. 

Fig. 6. Articular ball of a more posterior caudal centrum. * 

Fig. 7. Left lateral view of the same specimen, exhibiting the reduction iu the size of the 

diapophysls. > 

Fig. 8. Left lateral view of a more posterior caudal vertebra, devoid of diapophyses. 
Fig. 9. Supijosed femur, posterior view. 
Fig. 10. Supposed fibula. 
Fig. 11. Supposed tibia. 

Figs. 12, 13. Tylosaukus proriger. Specimens from the Cretaceous of Kansas, belonging to the 
Smithsonian Institution. 
Fig. 12. Extremity of the snout, or of the premaxillary. 

.Fig. 13. Posterior articular surface of the left spleuial bone of the lower jaw. 
Fig. 14. Tooth of a mosasauroid, uatural size, from tho Cretaceous of L'Eau qui Court 
County, Nebraska. The crown is compressed, conical, with acute borders and smooth sur- 
faces. The base is compressed oval, and it exhibits on its inner side a small concavity for 
the accommodation of a successor. 



^ K C'eoloni' al Harvey of the T 



erntones. 



rlateXXXY 




Ih" Sindau&Sonhth.nnla 



EXPLANATION OF PLATE XXXVI. 



Figs. 1-3. Tylosaurcs proriger: 

Figs. 1,2. A caudal vertebra, one-half the natural size. From the Cretaceous of Kansas. 

Smithsonian lustitution. 
Fig. 1. Left lateral view. Fig. 2. Posterior view. 
Fig. 3. A tooth which accompanied the former specimen, lateral view, natural size. 

Figs. 4-14. Lestosaurus corypii^us. All the figures one-half the natural size. From the Cretaceous 

of Kansas. Museum of the Smithsonian Institution. 
Fig. 4. Inferior view of a dorsal vertebra. Within the position of the right zygapophysis a 

rudimental zygosphene is observed. 
Fig. 5. Inferior view of a second specimen. 
Fig. 6. Inferior view of the body of a cervical vertebra. 
Fig. 7. Right lateral view of another cervical vertebra. 
Fig. 8. Left lateral view of an anterior caudal vertebra. 
Fig. 9. Same view of a more posterior specimen. 
Fig. 10. Posterior view of the same. 

Fig. 11. Left lateral view of the bodies of two posterior vertebraj. 
Fig. 12. Posterior view of the second of the latter. 
Fig. 13. Limb-bone, jirobably an ulna or a fibula. 
Fig. 14. Probably a radius or a tibia. 

Fig. 15. MosASAURUs: 

A caudal vertebra, from L'Eau qui Court County, Nebraska. Museum of Swarthmore Col- 
lege. Presented by George S. Truman. Inferior view one-half the natural size. 

Fig. 16. Tylosaurus dyspelor. Inferior view of the same caudal centrum as that of Fig. 4, of the 

preceding i)late. Half the natural size. 
Figs. 17-21. Limb-bones of a turtle, from the Cretaceous of Smoky Hill Eiver, Kansas. 

Smithsonian Institution. Three-fourths the natural size. 
Fig. 17. Upper extremity of the right humerus, anterior view. 
Fig. IS. The right femur, anterior view. 
Fig. 19. Portion of a left scapnla, inverted in position. The broken process to the loft is 

the precoracoid. Posterior view. 
Fig. 20. Portion of the coracoid. The articular surface at the upper end is for the scapula. 
Fig. 21. Portion of an undetermined limb-bone. • 



S ■.-;■ ~'lt)6^f^3-l 'Survey of tbe Terntonfts 



Plate XXXyi 




'VW^ Smclait & Son, litli . iTi-ui 



EXPLANATION OF PLATE XXXVIl". 



Figs. 1-3. AociiEXiA iie.sterna: 

Spceimeus from the Quaternary of California, and belonging to the cabinet of Wabasli 

College, Crawfordsville, Indiana. 
Fig. 1. Outer view of tlie series of lower molar teeth of the left side, one-half the natural 

size. 
Fig. 2. Triturating surfaces of the same series, natural size. 
Fig. 3. A second upper molar of the left side, view of the triturating surface, natural size. 

Fig. 4. Bison: 

Last lower molar of the left side, triturating surface, natural size. Specimen fonud with 
remains of Mcgalonijx Jeffersoiii, in Illinois. 

Fig. 5. AciiODU.s iiuMius. Magnifier; one and a half times. A'iew of the tritnrating surface of a tooth. 
From the Cretaceous of New Jersey. 

Figs. G-12. I'.D.U'iioDox MiKiFicu.s. One-half the natural size. Specimens from the Cretaceous of New 
Jersey, and belonging to the cabinet of Rutgers College, New Brnnswiek, New Jersey. 
Fig. fi. Tlie mandibles seen on tlieir oralsurt^iee. 
Fig. 7. Outer view of the left niandiljle. 
Fig. 8. Inni'r vicT of the left mandible. 

Fig. 9. Posterior outline of the same, -witli outlines of the dental columns. . 

Fig. 10. The maxillaj seen on their palatine or oral surface. 
Fig. 11. Outer view of the left nuixilla. 
Fig. 12. Posterior outline of the same, with outlines of the dental eohunns. 

1 igs. V^, II. Ef.MVLODUS L.iQUKATL'.S : 

Left lower maxilla, one-half the natural size. 
Fig. 13. Oral surface, exhibiting the dental tubercle. 

Fig. 14. Outer view. Specimen from the Cretaceous of Missi.ssippi, and discovered by Dr. 
William Spilhnan. 

Fig. 10. PoXTOBASiLEU.s TUHEi;crLATU.s. Fragment of a tjoth, with restored outline, natural size. 

Figs. If), IT. M.VNATCS INOKN.VTITS. A lower right molar, natural size. From the phosphate beds of 
Ashley Eiver, South Carolina. 
Fig. 16. Upper view. 
Fig. 17. Outer view. 

Figs. 18, 19. Pycxodus uobustus. Tooth of the natural size. 
Fig. 18. Triturating surface. 
Fig. 111. Posterior view. Specimen from the Cretaccons of Neu- .Jersey. 



D S. G;eolo6ica.l Survey ol' the Territories 



Plate JGCXYII 




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