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Full text of "The ancient fauna of Nebraska: a description of remains of extinct mammalia and chelonia, from the Mauvaises Terres of Nebraska"

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Smitl)0ontan €ontnbution6 to Hnoujlcbge. 



THE 



A. N C I E N T F A TJ N A 



NEBRASKA: 



OR, 



A DESCRIPnON ui' K!' .J.NS OF EXTINCT MAMMALIA AND CHELONIA, 



i- lOM in • I '•/USES TERRES OF NEBRASKA. 



lOSEPU LEIDY, M.l., 

il sfOB O* AHATOMY IN THB OTIIVBnSITY Of PKNN8VLVANI.V. 



W/ SITING '"ON CITY: 
PTBLISHED hY TM' SMITHSONIAN INSTITTTION. 

.1 i; N E, 1863. 

KEW YORK: G. P. PUTNAM &: CO. 



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SMITHSONIAN CONTRIBUTIONS TO KNOTV LEDGE. 



THE 



ANCIENT FAUNA 



NEBRASKA: 



OR, 



A DESCRIPTION OF REMAINS OF EXTINCT MAMMALIA AND CHELONIA, 



FROM THE MAIIVAISES TKRRES OF NEP.RA8KA. 



JOSEPH ^.EIDY, M. \)., 

I'BOFESSOE OP ANATOMY IN THE UNIVERSITY OF PENNSTLVANIA. 




[a CO EP TED rOlt PIl li I. I C ATION. T) F. C E M T! E K , 18 5 2.] 



V 1, VI 



COMMISSION 

TO WHICH THIS PAPER HAS BEEN REFERRED. 

Prof. James Hall. 
John L. Leconte, M. D. 

Joseph Henry, 

Secretary S. I. 



CONTENTS. 



Preface 
Introduction 



PAGE 

5 

7 



MAMMALIA. 







CHAPTER I. 














DESCRIPTIONS OP UNOULATA PARIDIGITATA . . .19 


Fam. 1. 


— RUMINANTIA ....... 

Poebrotherium ...... 

Wilsonii ..... 
Agriochoerus ...... 

antiquus ..... 
Oreodon 

Culbertsonii ..... 

gracilis ...... 

Comparison between Oreodon Culbertsonii and Oreodon gracilis 
Oreodon major ...... 

Eucrotaphus ...... 

Jacksoni ..... 

auritus ...'... 






19 
19 
19 
24 

24 
29 
45 
53 
55 
55 
56 
56 
56 


Fam. 2. 


— Paridigitata Ordinaria ..... 

Archaeotherium ..... 

Mortoni ..... 

robust urn ..... 






57 
57 
57 
66 




CHAPTKR II. 




DESCRIPTIONS OF UNOULATA IMPARIDIGITATA . . .67 


Fam. 1. 


— SOLIPEDIA ........ 






67 




Anchitherium . 
















67 




Bairdii . 
















67 


Fam. 2.- 


—IMPARIDIGITATA OrDINARIA 

Titauotherium . 

Proutii . 
Palaeothcrium . 

giganteum 
















72 
72 
72 
78 
78 




Rhinoceros 

occidentalis 
Nebrascensis 
















79 

81 

86 



Fain. 1. — DiGITIGRADA 

MacLairodus 

primaevus 



CONTENTS. 
CHAPTER III. 

CARNIVORA 



95 
95 
95 
95 



C II E L N I A 



CHAPTER I. 

Testudo ........... 101 

Ncbrascensis ......... 103 

hemispherica ......... 105 

Oweni .......... 106 

Culbertsonii . . . . . . . . .108 

lata 110 

Synopsis of the Genera and Species of Extinct Mammalia and Chelonia described in 

THIS Work .......... 113 

Index ............ 117 

ExPIiANATION OP THE Pl.ATES ......... 119 



PREFACE. 



The present Memoir, entitled " The Ancient Fauna of Nebraska," is founded 
upon a large and highly important collection of fossil remains of Mammalia and 
Chelonia, of the Eocene Period, from Nebraska Territory, which have been sub- 
mitted to me for examination by the Smithsonian Institution, Dr. David Dale Owen, 
of New Harmony, Indiana, and Dr. Hiram A. Prout and Prof O'Loghland, of St. 
Louis, to whom I express my sincere thanks for the interest they have taken in 
my labors. 

To Prof S. F. Baird, Dr. S. D. Culbertson, Messrs. Alexander, Joseph, and 
Thaddeus Culbertson, Capt. Stewart Van Vliet, Dr. S. G. Morton, Dr. John H. B. 
M'Clellan, Dr. A. H. Senseny, and Mr. J. S. Phillips, I am also obliged for the 
aid which they have contributed to the work. 

I embrace the present occasion to acknowledge the talent of the artists who 
have added so greatly to the value of the Memoir, by the excellent and faithful 
drawings which accompany it, viz. : Mr. A. Sonrel, of Woburn Centre, near Boston, 
and Messrs. A. J. Ibbotson, A. Frey, F. Shell, and I. Butler, of Philadelphia. 



INTRODUCTION. 



It has ceased to be a startling fact that, prior to the advent of man, a long series 
of ages had rolled by, during which numerous races of jilants and animals succes- 
sively originated and became extinct; and we no longer doubt our power to unveil 
the past, even to the period when the encrinite, the trilobite, and the brachiopod, 
were the sole representatives of life upon our planet. 

In the earliest known palaeozoic rocks, remains of invertebrate animals only 
have been found, and fossil fishes are first discovered in the upper Silurian forma- 
tions. Recently, remains of reptiles have been detected in the Old Red Sandstone 
of Morayshire, Scotland,^ but it was not until the middle of the Secondary Period 
that this class of animals appears to have reached the acme of its development. 

The era of the origin of birds will probably always be involved in more obscurity 
than that of the other vertebrata, as, from their physical construction, their remains 
are the least likely to be preserved. With the exception of footprints, supposed 
to be those of birds, but which may yet prove to be of reptiles, in the sandstone 
and conglomerate of the valley of the Connecticut, no truly characteristic remains 
of the former class have been discovered in any of the primary or secondary fossili- 
ferous strata. 

Of mammalia, a few undoubted remains have been found even as low in the 
geological series as the Trias. Prof. Plieninger recently discovered, in the bone- 
breccia of Wiirtemberg, two molar teeth, supposed to have belonged to an insect- 
ivorous animal, to which the name Microlesfes antiqims has been given." In the 
same deposit. Prof Plieninger found several incisor teeth, which he considers to 
have appertained to a species of fish allied to Sargus, and, therefore, proposes for 
the animal the name of Sargodon, but Jaeger suspects they also may have be- 
longed to a mammal, which was allied to the AnopJotherium, Cuvier.^ 

In the Stonesfield slate of Oxfordshire, England, belonging to the Oolitic Period, 
seven halves, singularly enough, of lower jaws, have been discovered, which have 
been referred to three species of two genera of insectivorous marsupialia : the Am- 
phigonus Prevostii, Ag. ; Amphigonus Broderipii; and the Phascolotherium Buck- 
landii, Owen.* 

' Telerpeton elginense, Mantell : Quart. Journ. Geolog. Soc, 1852, VIII. 100. 
" Wurtemb. naturw. Jahresb., 1847, III. H. 2, 164. 
^ Fos. Siiugeth. Wiirtemb., 1850, l.SO. 

* Jahrb. von Leon.u.Bronn, 1835, 186; Owen: Trans. Geol. Soc, 1841, VI. 47,58; Brit. Fos. Mam., 
29, 61. 



8 INTRODUCTION. 

In Europe, uo remains of mammals have been detected in the cretaceous series, 
but in this country several vertebrae have been found in the Green Sand of New 
Jersey, associated with bones of the Mososaurus, which I have referred to two 
species of cetacea, under the names of Priscodelj)hinus grandcevits and Priscodel- 
phinus Harlani} 

The tertiary geological period is remarkable for the great number of mammals 
which have been ushered into existence in successive races, and in the same course 
have become extinct. 

In Europe, the earliest tertiary or eocene formations have yielded an extraor- 
dinary abundance of mammalian fossils, in which we have reason to feel a peculiar 
interest, as, through the brilliant genius of Cuvier, they became the opening chapter 
to the great volume of palajontological science. 

Until recently, in North America, the only mammalian genus which had been 
detected as a member of the early Tertiary Period was the huge cetacean, the 
BasUosaums, Harlan, from the eocene deposits of Louisiana, Alabama, and South 
Carolina. Of this genus several distinct species have been indicated as follow : — 

Basilosatjrtjs cetoides, Gibbes : Journ. Ac. Nat. Sc, 1847, 1. 5. 

Zemjlodon cetoides, Owen: Trans. Geol. Soc, 1841, VI. 69. 

Zewjiodon inacrospondi/his, Miiller: Fos. Ees. d. Zeug., 1849. 
Basilosaukus serratus, Gibbes: Journ. Ac. Nat. Sc, 1847, I. 5. 

Zevglodon hrachyspondi/lxis, Miiller: Fos. Bes. d. Zeug., 1849. 
Basilosaurus PYGM.a;us ? 

Zeiifjlodon 2iygniseus'( Miiller: Fos. Res. d. Zeug., 1849. 

Quite lately, I referred a cervical vertebra found at Ouachita, Louisiana, to a new 
genus of cetacean animals under the name: 

PoNTOQENEUS PRiscus ? Leidy : Proc. Ac. Nat. Sc, 1852, VI. 52. (This may belong to the Basilo- 
saurus pygmmiis.^ 

Very numerous remains of extinct mammalia have also been discovered in the 
miocene and pliocene deposits of Europe, and likewise in those of the latter period 
in the Sivalik Hills of the Himalayas of India, in South America, and Australia. 

The mammalia, which have been indicated as belonging to the Miocene Period 
of North America, are as follow : — 

Phoca Wymani, Leidy. "Wyman: Am. Journ. Sc, 1850, X. 229. 

Phocodon, Agassiz. Wyman: Ibid., 56. 

Delphinus Calvertensis, Harlan: Proc Nat. Inst. "Washington, 1842, II. 195. 

Delphinus Conradi, Leidy: Proc. Ac. Nat. Sc, 1852, VI. 35; Wyman: Am. Journ. Sc, 1850, X. 231. 

BAL.ffi;NA PALiEATLANTiCA, Leidy : Proc. Ac. Nat. Sc, 1851, V. 308. 

BAL.a;NA PRISCA, Leidy : Ibid. 

In the pliocene deposits of this country the remains of extinct mammalia are 
very numerous, and a large number of species have been determined as follow : — 

Cervus americanus, Harlan: Fauna Amer., 1825, 245. 



» Proc. Ac. Nat. Sc, 1851, V. 327. 



INTRODUCTION. 



Cervus ? 

Elaphus ammcanus, Be Kay: Nat. Hist. New York, 1842, Pt. I., Zool. Mam., 120.' 
Bison latifrons, Leidy: Proc. Ac. Nat. Sc, 1852, VI. 117 j Smiths. Contrib. to Knowl., 1852, V. 8. 

Bos latifrons, Harlan: Fauna Amer., 1825, 273. 
Bison antiquus, Leidy: Proc. Ac. Nat. Sc, 1852, VI. 117; Smiths. Contrib. to Knowl., 1852, V. 11. 
BoOTHEBiOM CAVIFRONS, Leidy: Proc. Ac. Nat. Sc, 1852, VI. 71; Smiths. Contrib. to Knowl., 1852, 
V. 12. 
Bos PaUasii (in part), Pekay : An. Lye. Nat. Hist, of N. York, 1828, IL 280. 
BOOTHERIUM BOMBIFRONS, Leidy: Proc Ac Nat. Sc, 1852, VI. 71; Smiths. Contrib. to Knowl., 1852, 
V. 17. 
Bos homhlfrons, Harlan : Faun. Amer. 1825, 271. 
Ovis MAMMiLARis? Hildreth : Am. Journ. Sc, 1837, XXXI. 82. 
Haklanus americanus, Owen: Proc. Ac. Nat. Sc, 184G, III. 91; Journ. Ac. Nat. Sc, 1847, I. 18. 

Sus amcricana, Harlan: Amer. Journ. Sc, 1842, XLIII. 143. 
Platygonus compressus, Le Conte: Am. Journ. Sc, 1848, V. 103 ; Trans. Am. Ac. Arts, 1848, III. 

257; Leidy: Trans. Am. Phil. Soc, 1852, X. 323. 
DiCOTTLES depressiprons, Le Conte: Proc. Ac. Nat. Sc, 1852, VI. 3; Leidy: Trans. Am. Phil. Soc, 
1852, X. 323. 

DiCOTYLES TORQUATUS (JoSsiUs). 

Dicotyles costatus, Le Conte: Proc. Ac. Nat. Sc, 1852, VI. 5. 
Protochcerus prismaticus, Le Conte: Am. Journ. Sc, 1848, V. 105; Leidy: Trans. Am. Phil. Soc, 

1852, X. 323. 
EucncERUs MACROPS, Leidy: Trans. Am. Phil. Soc, 1852, X. 323. 
Equus americanus, Leidy : Proc. Ac. Nat. Sc, 1847, III. 262. 
HiPPARiON VENUSTUM, Leidy : Proc. Ac. Nat. Sc, 1853, VI. 241. 

Tapirus americanus (fossilis). Carpenter: Am. Journ. Sc, 1842, XLII. 390; Ibid., 1846, I. 247; 
Leidy: Proc. Ac. Nat. Sc, 1849, IV. 180. 

Tcqnrus mastodontoides, Harlan : Fauna Amer., 1825, 224. 
Tapirus Haysii, Leidy : Proc. Ac Nat. Sc, 1852, VI. 148. 
Elephas americanus. (^The fossil elephant of North America.') 

Elephas primigenius, Blumenbach. In part, of numerous authors. 
Mastodon giganteus, Cuvier. See numerous authors. 
Ursus americanus (fossilis). Leidy : Proc Ac. Nat. Sc, 1853, VI. 
Ursus amplidens, Leidy : Proc. Ac. Nat. Sc, 1853, VI. 
Felis atrox, Leidy : Trans. Am. Phil. Soc, 1852, X. 319. 
Procyon pbiscus, Le Conte : Am. Journ. Sc, 1848, V. 106. 
Anomodon Snyderi, Le Conte : Am. Journ. Sc, 1848, V. 106. 
Castor fiber {fossilis). Wyman : Am. Journ. Sc, 1850, X. 61. 
Castoroides ohioensis, Foster: Second Ann. Rep. of the Geolog. Survey of Ohio, 1838, 80, 81; 

Wyman : Boston Journ. Nat. Hist. Soc, 1846, V. 385. 
Oromys ^sopi, Leidy : Proc. Ac Nat. Sc, 1853, VI. 241. 
Megatherium mirabile, Leidy : Proc. Ac. Nat. Sc, 1852, VI. 117. 

Megatherium, Cuvier. Cooper : An. Lye. Nat. Hist, of N. York, 1824, 1. 114 ; Ibid., 1828, II. 267 ; 
Hodgson : Mem. on the Megatherium, 1846. 

Megatherium Cuvieri, Desmarest. Harlan : Fauna Amer., 1825, 200. 
Meoaxonyx Jeffersonii, Harlan: Fauna Amer., 1825, 201. 

Megalonyx laqiieatiis, Harlan : Journ. Ac. Nat. Sc, 1838, VI. 269. 

Aulaxodon s. Pleurodon, Harlan : IMed. and Phys. Researches, 1835, 330. 
Megalonyx dissimilis, Leidy: Proc. Ac. Nat. Sc, 1852, VI. 117. 



' This may prove to be a new species, but it certainly is not the Cervus americanus of Harlan, as is 
supposed by Dr. De Kay, for the remains of the latter indicate an animal even greater in size than the 
Irish Elk. 



10 INTRODUCTION. 

Mylodon Harlani, Owen : Zool. Voy. Beagle, Pt. I., 1840, 68. 

Megalonyx laqueatm, Harlan : Med. and P-hys. Researches, 1835, 334. 

Orycterothcrium Missouriensc, Harlan : Proc. Am. Phil. Soo., 1841, 11. 119 ; Am. Journ. Sc., 1843, 
XLIV. 69. 

Oi-ycterotherium Oregonensis, Perkins : Am. Journ. Sc, 1843, XLIV. 80. 
Ereptodon priscus, Leidy: Proc. Ac. Nat. So., 1853, V. 241. 
EUBRADYS ANTIQUUS, Leidy : Ibid. 

Mcgalonyx jMtens, Leidy: Proc. Ac. Nat. So., 1852, VI. 117. 
Delphinus vermontanus? Thompson: Am. Journ. Sc, 1850, XI. 256. 
Trichecus virginianus? Dekay : Nat. Hist. New York, 1842, Pt. I., Zool. Mam., 56. 
. Trichecus. Blitchell, Smith, and Cooper: An. Lyo. Nat. Hist. N. York, 1828, II. 271. 

Trichecus rosmariis (fossilis). Harlan : Med. and Phys. Researches, 1835, 277. 
Manatus, Cuvier. Harlan : Journ. Ac. Nat. Sc, 1825, IV. 236; Med. and Phys. Researches, 1835, 278. 
Rorqdalis australis (fossilis). Dekay : Nat. Hist. New York, 1842, Pt. I., Zool. Mam. 99.' 

In addition to the species just enumerated, remains of numerous mammals and 
other vertebrates have been discovered, by Prof. S. F. Baird, in various caves of 
Pennsylvania and Virginia, and are now deposited in the Museum of the Smith- 
sonian Institution.^ The collection contains representatives of nearly all the 
larger recent mammals and turtles of the United States, together with a few 
extinct species. 

The particular object of the present memoir is the description of a large and 
highly important collection of remains of mammalia and chelonia from an exten- 
sive Eocene deposit, which immediately overlies the Green Sand of the Cretaceous 
Period, in the Mauvaises Tenses of Nebraska Territory. 

The Mauvaises Terres, or Bad Lands, as they are named, constitute a district of 
country extending along the foot of the Black Hills, a spur of the Rocky Mountains, 
situated between the Platte, or Nebraska, and the Missouri Rivers, at the head of 
certain branches of the latter called the L'Eau-qui-coLirt, White, Cheyenne, and 
Moreau Rivers.^ 

Dr. Owen, in describing this region, from notes of a visit made to it by Dr. John 
Evans, in his magnificent "Report of a Geological Survey of Wisconsin, Iowa, and 
Minnesota, and incidentally of a portion of Nebraska," observes that it presents one 
of the most extraordinary and picturesque sights that can be found in the whole 
Missoui'i country.* 

• 
' The following are erroneously reported as fossil remains: — 

Rhinoceroides Alleghaniensis, Featherstonhaugh : Journ. of Geol. 1831, I. 10. This is no animal 
remain whatever, hut is merely a fragment of stone. See De Blainville's Osteographie, article Rhino- 
ceros, p. 172. Further confirmed by Dr. Isaac Hays and Mr. Isaac Lea, who have had an opportunity 
of inspecting the specimen. 

Osteopera platycephala, Harlan : Fauna Amer., 126. The cranium described under this name is 
now preserved in the Cabinet of the Academy of Natural Sciences, and without the slightest doubt 
belongs to the recent Coelogcnys paca, Rengger, of South America. 

Eqdus caballus ? 

Equus major, Dekay: Nat. Hist. New York, Pt. I., Zool. Mam., 108. 
Equus curvidens, Owen. Leidy : Proc. Ac. Nat. Sc, 1847, III. 262. 
' See Proceedings of the American Association, at Cambridge, 1849, II. 352. 
' See the map accompanying this memoir, for the use of which I am indebted to Dr. D. D. Owen. 
* P. 196. 



INTRODUCTION. 



11 



" From the high prairies that rise in the back-ground, by a series of terraces 
towards the spurs of the Rocky Mountains, the traveller looks down into an exten- 
sive valley ,^that may be said to constitute a world of its own, and which appears 
to have been formed, partly by an extensive vertical fault, partly by the long con- 
tinued influence of denudation. 

" The valley is about ninety miles in length, and thirty in breadth, and stretches 
away, westwardly, towards the base of the dark gloomy range of mountains, the 
Black Hills. Its most depressed portion is about three hundred feet below the 
general level of the surrounding country, and is covered by a soil, similar to that 
of the higher ground, supporting scanty grasses. 




View of the Mauvaises Terres. — From the Geological Report of Dr. Owen. 



" To the surrounding country, however, the Mauvaises Terres joresent the most 
striking contrast. From the uniform, monotonous, open prairie, the traveller sud- 
denly descends, one or two hundred feet, into a valley that looks as if it had sunk 
away from the contiguous world; lea\nng standing, all over the surface, thousands 
of abrupt, irregular, prisniatic, and columnar masses, frequently capped with irre- 
gular pyramids, and extending to a height of one or two hundred feet, or more. 

" So thickly are these natural towers studded over the surface of this extraor- 
dinary region, that the traveller threads his way through deep, confined, labyrin- 
thine passages, not unlike the narrow irregular streets and lanes of some quaint 
old town of the European continent. Viewed in the distance, indeed, these rocky 
piles, in their endless succession, assume the appearance of massive artificial struc- 



12 INTRODUCTION. 

tures, decked out with all the accessories of buttress and turret, arched doorway and 
clustered shaft, pinnacle, finial, and tapering spire. 

" One might almost imagine he was approaching some magnificent city of the 
dead, where the labor and the genius of forgotten nations had left behind them a 
multitude of monuments of art and skill. 

" On descending from the heights, however, and proceeding to thread this vast 
labyrinth, and inspect in detail its deep intricate recesses, the realities of the scene 
soon dissipate the delusions of the distance. The castellated forms which fancy 
had conjured up have vanished; and on every side appears bleak and barren 
desolation. 

" Then, too, if the exploration be made in summer, the scorching rays of the 
sun, pouring down in the hundred defiles that conduct the wayfarer through this 
pathless waste, are reflected back from the white or ash-colored walls, that rise 
around unmitigated by a breath of air or the shelter of a solitary shrub. 

" The drooping spirits of the scorched geologist are not permitted, however, to 
flag. The fossil treasures of the way, well repay its sultriness and fatigue. At 
every step, objects of the highest interest present themselves. Embedded in the 
debris, lie strewn, in the greatest profusion, relics of extinct animals. All speak of 
a fresh-water deposit of the early Tertiary Period, and disclose the former exist- 
ence of most remarkable races, that roamed about in bygone ages high up in the 
valley of the Missouri, towards the sources of its western tributaries; where now 
pasture the Big Horn (Ovis montana) and the Buffalo {Bison americanus) ." 

Mr. Thaddeus A. Culbertson, who visited the Mauvaises Terres in 1850, under 
the auspices of the Smithsonian Institution, and made a good collection of its animal 
remains, has given a description of this remarkable country closely corresponding 
with that just detailed. In one part of his journal, he observes : " The road now lay 
over hills which became more steep and frequent as we approached the Bad Lands. 
These occasionally appeared in the distance, and never before did I see anything 
that so resembled a hxrge city; so complete was this deception that I could point 
out the public buildings ; one appeared to have a large dome, which might be the 
town hall ; another, with a large angular top, suggested the idea of a court>house, 
or some other magnificent edifice for pul)lic purposes; and then appeared a i"ow of 
palaces, great in number and superb in all their arrangements. Indeed, the thought 
frequently occurred as we rode along, that we were approaching a city of palaces ; 
with everything upon the grandest scale, and adapted for giants, who might have 
ruled the huge animals, whose remains are there still, and not for pigmies, such as 
now inhabit the earth: Again and again, as from different positions this region 
was visible, thoughts of an immense city would arise in my mind, and I could 
almost fancy its din and bustle were occasionally borne upon the wind to my ear."^ 

The structure of the columnar rocks of the Bad Lands, according to the report 
of Dr. Evans, quoted in the work of Dr. Owen, before indicated, is as follows : — 



' Journal of an Expedition to the Mauvaises Terres and the Upper Missouri in 1850. Fifth An. Rep. 
of the Smiths. Inst., p. 84. 



3 


ii 


8 


a 


30 


a 


8 


it 


1 inch, 


25 feet. 


15 


a 


8 


a 



INTRODUCTION. 13 

Section of Beds constituting the early tertiary {^Eocene) of tlie Bad Lands [3fauvaises 
Terres). — (Numbered in the descending order.) 

1. Ash-colored clay, cracking in the sun, containing silicious concretions 30 feet. 

2. Compact white limestone ........ 

3. Light-gray marly limestone ........ 

4. Light-gray indurated silicious clay (not effervescent) 

5. Aggregate of small angular grains of quartz, or conglomerate, cemented 
by calcareous earth (slightly effervescent) ...... 

6. La3-er of quartz and chalcedony (probably only partial) 

7. Light-gray indurated silicious clay, similar to number 4, but more 
calcareous, passing downwards into pale, flesh-colored, indurated, silicious, 
marly, limestone (effervescent), turtle, and bone bed .... 

8. White and light-gray calcareous grit (slightly effervescent) 

9. Similar aggregate to number 5, but coarser ..... 

10. Ligh1>green, indurated, argillaceous stratum (slightly effervescent), 
Titanotherium bed ........... 20 feet. 

The extensive cemetery of eocene vertebrata in the Mauvaises Terres, or Bad 
Lands, of Nebraska, was first brought to our notice in a communication entitled 
Description of a Fossil Maxillary Bonje of a Palmotlierium, from near White River, 
published by Hiram A. Pi'out, M. D., of St. Louis, in the American Journal of 
Science and Arts, for 1847, page 248. 

Nearly at the same time, Mr. J. S. Phillips, when on a visit to Chambersburg, 
Pennsylvania, observed in the possession of Dr. S. D. Culbertson, several remark- 
able mammalian fossils, which had been sent as curiosities from the Bad Lands by 
his nephew, Mr. Alexander Culbertson, of the American Fur Company. These 
sijecimens, at the suggestion of the late distinguished Dr. S. G. Morton, were 
obtained through Dr. John H. B. McClellan, a friend of Dr. Culbertson, and were 
obligingly placed in my hands for examination. A description of them was pub- 
lished in the Proceedings of the Academy of Natural Sciences, of Philadelphia, for 
1847 and 1848; and they were afterwards presented by Alexander Culbertson 
to the Academy. 

The attention of Dr. D. D. Owen having been directed to the interesting region 
whence the fossils were obtained, he requested Dr. John Evans, an assistant in 
the geological survey in which he was engaged, to pay it a visit. This gentleman 
brought home a magnificent collection of fossils, which form the basis of one of 
the chapters in the Report of Dr. Owen, before quoted.^ 

Through the instrumentality of Prof S. F. Baird, who from the first fully appre- 
ciated the importance of a complete examination of the Mauvaises Terres and their 
animal remains, Mr. Thaddeus A. Culbertson, under the auspices of the Smith- 



Dr. J. Leidj's Memoir, p. 533, of the "Report of a Geolog. Surv. of Wise., etc." 



14 INTRODUCTION. 

sonian Institution, visited the locality in 1850, and brought home a valuable addi- 
tional collection of mammalian and chelonian fossils. 

From a variety of favorable circumstances, but especially through important aid 
from the Smithsonian Institution, and Dr. D. D. Owen, I have been enabled per- 
sonally to inspect all the animal remains brought from Nebraska, of which I have 
had any intimation. In commencing, then, with a description of the Eocene Fauna 
of Nebraska, the following collections were submitted to investigation. 

1. The original fragment of a maxillary bone described by Dr. Prout, with the 
addition of several other important specimens. These were kindly loaned by Dr. 
Hiram A. Prout, of St. Louis. 

2. A collection which accompanied the former, belonging to, and obligingly 
loaned by Prof. O'Loghland, of St. Louis. 

3. Specimens presented by Alexander Culbertson, Esq., through Joseph Cul- 
bertson, Esq., to the Academy of Natural Sciences, of Philadelphia. 

4. The collection made by Dr. John Evans, at the instigation of Dr. D. D. 
Owen, for the United States Government, and now belonging to the Smithsonian 
Institution. 

5. A collection procured, as above mentioned, by Mr. Thaddeus A. Culbertson, 
for the Smithsonian Institution. Very important aid in making this collection was 
rendered by Mr. Alexander Culbertson. 

6. A small but very excellent collection made by Captain Stewart Van Vliet, of 
the United States Army, and by him presented to the Smithsonian Institution. 
These specimens, though last received, were actually among the first collected, 
having been procured by him when on a journey from Fort Pierre to Fort Lara- 
mie, in company with Mr. Alexander Culbertson, who, on the same occasion, ob- 
tained the specimens first described by me. 

Most of the specimens when received, were partially enveloped by, or had 
attached to them a hard, silicio-calcareous clay, of a dirty cream color; and the 
same material fills the cavities of the skulls and the interior of the turtle shells. 

This matrix, according to Dr. D. D, Owen, has the following composition : — ^ 

Water of absorption ......... HO 2.50 

Flesh-colored silicious earth, insoluble in ehlorohyjric acid . . 3.3.00 

Lime CaO 30.90 

Carbonic acid CO^ 19.00 

Sesquioxide of iron Fe^Og 2.00 

Alumina AlA 1.00- 

Manganese MnO 1.00 

Magnesia MgO 1.00 

Phosphoric acid ......... 1.80 

Chlorine CI 0.44 

Potash KG 4.08 

Soda and loss NaO 3.28 

100.00 



'■ Rep. of a Geolog. Surv. etc., p. 606. 



INTRODUCTION. 15 

A portion of the matrix attached to the bones of the Titanotherium, obtained 
from the lowest bed of the geological section. No. 10,. p. 13, also analyzed by Dr. 
Owen, was found to be composed as follows: — - 

"Water HO 4.00 

Silica SiO, 59.00 

Lime CaO 10.00 

Carbonic acid . . . . • CO^ 12.20 

Sesquioxide of iron Fe^Oa 7.20 

Alumina Al^Oj 4.20 

Phosphoric acid ......... 1.90 

Chlorine CI 0.037 

Sulphuric acid SO3 0.03 

Alkalies and loss . . ....... 1.433 

100.000 

The bones, unlike tho.se of the gypsum quarries of Montmartre, (which are 
of the same age but not mineralized) are as completely petrified as any found in 
the most favorable circumstances. Most usually they are exceedingly hard, com- 
pact, and heavy, and only rarely have they become friable. The cellular, vascular, 
and medullary cavities are filled with mineral matter, in most instances, consist- 
ing of crystallized or amorphous silex or chalcedony, which is sometimes botryoidal 
in its arrangement in the larger cavities. 

The bones are preserved in very various degrees of integi'ity, some being beau- 
tifully perfect, whilst others are crushed or otherwise fractured, the crevices being 
filled with the ordinar}^ matrix, or with a harder mineral matter. The latter 
evidently were subjected to violence while enveloped in a soft mud which now 
constitutes the matrix; for in most instances in which the fragments have been 
widely separated, they still retain their proper relative position to one another. 

The teeth, where they exist, are usually preserved quite perfect, and in all cases 
their pulp cavities are filled with dense amorphous, or with crystallized silex. 

The dentine is commonly of a cream color, or pure white, but occasionally it is 
tinged with a roseate hue; and in most cases where exposed from the enamel having 
been worn off, it is covered by a lamina of compact peroxide of iron. Its texture is 
firm, though more friable than in the recent condition. The enamel is well pre- 
served in texture, but in every instance is stained. Its color passes from trans- 
lucent light brown resembling horn, through different shades of brown, to black 
with a brown or bluish tinge. Its surface is highly lustrous, and in those cases in 
which it is dark in color, resembles polished steel. 

The bones are cream white, yellowish, brownish, brown, and iron gray, and 
most frequently have a slightly polished surface. Very often a thin layer of 
brown oxide of iron adheres to the latter, and is difficult to detach, without re- 
moving a portion of the osseous structure. 

None of the specimens have the appearance of being water worn, or rolled, but 
all the teeth and processes of bone, when entire, exhibit all their original sharpness 



' Rep. of a Gcolog. Sury. etc, p. 606. 



16 



INTRODUCTION. 



of outline, indicating that the carcasses of the animals to which they belonged 
decayed upon a soft, muddy bottom of a lake or similar body of water. 

An analysis of portions of some of the bones and teeth having been made by Dr. 
Francis B. Greene, under the immediate inspection of Dr. F. A. Genth, at the re- 
quest of Dr. D. D. Owen and myself, the following results were obtained :— 

Specimen 1. Fragment of an os femoris of Titanotherium. This was compact, 
Avith a subconchoidal fracture, and tough. Its hardness was = 4.5 ; the sp. gr. = 
2.870. Lustre resinous. Color brown; opaque. On heating, it eliminated an 
ammoniacal water, together with the odor of burnt horn. 

Specimen 2. Fragment of a tibia of Archceotherium. This was compact, and 
presented an uneven, somewhat splintery, fracture. Its hardness was = 4.; the 
sp.gr. = 2.826. Lustre pearly. Color pinkish white; opaque. When heated in 
contact with the air, it assumed a green tint from the development of manganic 
acid. 

Specimen 3. Fragment of enamel from a molar tooth of Tiianotherium. Appear- 
ance fibrous, with an uneven fracture, and very tough. Its hardness was = 4.7; 
the sp. gr. = 4.7. Lustre upon the surface subvitreous, that of the fibres pearly. 
Color bluish gray, opaque. 

Specimen 4. Fragment of dentine, from a molar tooth of Titanoilierium. It was 
compact, and had an uneven, somewhat subconchoidal fracture. Its hardness was 
= 2.5; the sp. gr. = 2.935. Lustre dull. Color white, with gray spots and black 
streaks; opaque. On heating, in contact with the air, it assumed a greenish tint. 



Sesquioxide of iron 

Oxide of manganese 

Magnesia 

Lime 

Fluoride of calcium 

Baryta 

Soda . 

Potassa 

Silica 

Sulphuric acid 

Phosphoric acid 

Carbonic acid 

Chlorine 

Water 

Organic matter 



COMPOSITION. 










Spec. 1. 


Spec. 2. 


Spec. 3. 


Spec. 4 


PeA 


1.777 


trace 


trace 


trace 


MnO 


trace 


trace 


trace 


trace 


MgO 


0.348 


1.140 


0.219 


0.53 


CaO 


49.837 


47.052 


51.872 


49.82 


CaFl 


0.716 


5.086 


0.099 


2.90 


BaO 


■ 0.359 


1.131 






NaO 


1.134 


1.572 


1.288 


0.75 


KO 


0.317 


0.276 


0.239 


0.23 


SiO, 


0.135 


0.259 


0.611 


0.79 


SO3 


1.067 


2.200 


1.011 


1.51 


PO. 


34.148 


32.957 


39.348 


36.10 


CO, 


4.088 


2.270 


3.165 


2.83 


CI 


trace 


trace 


trace 


trace 


HO 


2.048 


1.971 


0.626 


2.10 


• 


5.682 


4.086 


2.538 


2.66 



101.656 



100.000 



101.016 



100.22 



Or, the composition may be considered thus : — 



INTRODUCTION. 



17 







Spec. 1. 


Spec. 2. 


Spec. 3. 


Spec. 4 


Phosphate of iron 


. 2FeA>3P05 


2.821 








" magnesia 


. 3Mg0,P05 


0.770 


2.099 


0.403 


0.98 


lime 


. 3CaO,P05 


69.68.5 


68.582 


83.835 


77.81 


" soda 


. 2NaO,P05 


1.415 


1.079 


1.413 




Sulphate of baryta 


. BaO,S03 


0.547 


1.723 






" soda 


. NaO,S03 


1.083 


2.443 


1.437 


1.71 


" potassa 


. KO.SOa • 


0.587 


0.510 


0.442 


0.48 


lime 


. CaO,S03 








0.60 


Silicate of lime . 


. SCaO.SiOa 


0.382 


0.732 


1.727 


2.23 


Carbonate of lime 


. CaO.CO^ 


9.315 


5.172 


7.212 


6.45 


Lime . 


. CaO 


6.605 


6.517 


1.284 


2.35 


Fluoride of calcium 


. CaFl 


0.716 


5.086 


0.099 


2.90 


Water 


. HO 


2.048 


1.971 


0.626 


2.10 


Organic matter 




5.682 


4.086 


2.538 


2.66 



101.656 100.000 101.016 



100.22^ 



Cuvier, in speaking of the remains of mammalia in the gypsum quarries of the 
Paris basin observes, " on peut s'etonner que dans une contree aussi etendue que 
celle qu'occupent nos carrieres, et qui a plus de vingt lieues de Test a I'ouest on 
n'ait presque trouve que des os d'animaux d'une seule famille, et que le petit 
nombre d'especes etrangeres a cette famille principale, y soient d'une rarete ex- 
treme." The distinguished author infers from this a condition analogous to that 
presented in our day by Australia. More recent researches, however, have shown 
that in the single family alluded to, the PacJii/dermata, he included members really 
belonging to one of the other Cuvierian families; for the Anoplotherium and Di- 
chohune are now generally considered to have been true ruminating animals. 

With a single exception, all the species of extinct mammalia, which have yet 
been obtained from Nebraska, belong to the Ungulata, and, as in the case of those 
of the Paris basin above referred to, consist of Ruminantia and Pachydermata. 

The great order of Ungidata, or hoofed mammalia, according to the idea originally 
expressed by Cuvier, and confirmed by De Blainville, but more especially by Owen, 
is divisible into two distinct sub-orders, the Paridigitata or even-toed ungulates, and 
the Imparidigitata, or uneven-toed ungulates. 

The sub-order Paridigitata may be divided into the families Ruminantia and 
Ordinaria. 

The Ruminantia are further divisible into sub-families as follows : — 

1. Those which are hornless, and have incisors and canines in both jaws; as 
Anoplotheri^im, Macrauclienia, Dichohune, ChalicoiJierium, etc. 

2. Those which are hornless, and have canines and an incomplete series of in- 
cisors or none at all, in the upper jaw ; as Gamelus, Auchenia, Moschus, Dorcathe- 
ri'um, etc. 

3. Those which have processes of the os frontis, or have antlers, in one or both 
sexes, and have or have not upper canines, or have them in a rudimentary con- 
dition, and which are without upper incisors ; as Cervics, Cameloepardalis, etc. 



Proc. Acad. Nat. Sc, VT. 292. 



18 INTRODUCTION. 

4. Those wliich possess true horns, and have neither upper canines nor incisors; 
as Ant'dope, Bos, Ovis, etc. 

The Paridigitata ordinaria are represented by Sus, Dicotijles, HippoiMtamics, Clice- 
ropotamus, Anthracotherium, Ilyracotherium, etc. 

The second sub-order of Urujidata is divisible into the following families : — 

SoUpedia, represented by Equus, Hipparion, Ancliiiherium, etc. 

Ordinaria, to which belong Rhinoceros, Tapirus, Pala:otlierium, etc. 

Prohoscidia, containing Eleplias and Mastodon. 

Of the mammalia from Nebraska, which will be described according to the pre- 
ceding arrangement, there are seven species of four genera which belong to the 
Ruminantia, two species of one genus to the Paridigitata ordinaria, one species to 
the Soliptedia, and four species of three genera to the Imparidigitata ordinaria. 

The exceptional case above referred to, belonging to a different order from the 
Ungulaia, is a carnivorous animal of the feline genus Machai7-odtis. 

The chelonian fossils from Nebraska, of which there are five species, belong all 
to the genus Testudo. 



MAMMALIA. 



CHAPTER I. 
DESCRIPTIONS OF UNGULATA PARIDIGITATA. 

Fam . 1 . — EUMINANTIA. 
Gen. POEBROTHERIU]n, Leidy. 

Poebrotheriiim Wilsonii, Leidy. 

(Plate I. Figs. 1-4.) 

PoebroiJicriiim WHsonii, Leidy: Proceedings of the Academy of Natural Sciences of Philadelphia, 1847, III. 
322; Owen's Rep. of a Geol. Surv. of Wise, etc., 1852, 571. 

Poehroiherium is a peculiar genus of ruminants, among recent animals most 
nearly allied to the Musks, and probably belongs to the second sub-family according 
to the characters before indicated. 

The species Poehroiherium Wilsonii was established upon the greater portion of a 
skull, which was the first mammalian fossil, sent to the Academy of Natural 
Sciences of Philadelphia, from the eocene beds of Nebraska. It was presented 
by Mr. Alexander Culbertson, of Chambersburg, Pennsylvania, and, when first re- 
ceived, excited great interest among the members of the Academy, as being an 
indication of the rich palteontological treasures since derived from the same locality. 

The specimen has lost the symphysis of the lower jaw, the end of the nose, one 
zygoma, the upper part of the face, and the upper and posterior part of the 
cranium. It is also much fractured and fissured; but the portions of it which 
remain appear to have very well retained their original relative position. 

It belonged to an individual just reaching adult age; the permanent true molars 
having protruded, but none of the deciduous molars having been shed. In the 
upper jaw the molars are preserved on both sides, but several of those upon the 
left side are broken. This series consists of the three permanent true molars and 
three deciduous molars in a continuous row, and the first permanent premolar 
separated by a hiatus from the others. (PI. I. Figs. 1, 3.) In the lower jaw, on the 
left side, are preserved five, and on the right side six teeth, viz., three permanent 
true molars, and three deciduous molars, forming a continuous row. (Figs- 1; 4.) 



20 POEBROTHEKIUM. 

When the specimen was received, the right side of the lower jaw contained a 
fragment of a fang, sepai'ated from the remaining molars by a hiatus, and situated 
just in advance of the position of the first permanent premolar above, with which 
it most probably corresponded. 

The form of the head, if restored, would probably most approach that of the 
existing Musks, or the extinct Dorcatherium, Kaup, from the Middle Tertiary Form- 
ations of Europe. The face is relatively longer than in either of these genera, 
and is also more advanced in position ; for in Poebrolhermm the anterior margin 
of the orbit is on a line with the middle of the penultimate true molar, whereas in 
Dorcatherium it is in advance of this, and in the Musks it is anterior to the first. 

At the side of the nose, the face is depressed into a remarkably deep concavity, 
at the bottom of which the ossa maxillaria of tlie two sides are nearly in contact ; 
and the face, in this position, is only about two lines and a half in diameter. (Figs. 
1, 2.) The depression may, to some extent, be the result of accident after the 
death of the animal, for the specimen is fractured; the parts, however, generally 
appear to have retained their natural position. 

BofcatJierium also presents a concavity holding nearly the same relative position ; 
but, in consequence of the distance between the orbit and the bottom of the canine 
alveolus being comparatively short in this genu^ the depression is close to the 
orbit; whereas, in Poebr other lum it is far advanced by reason of the prolongation 
of the fixcc, which converges from the margin of the orbit to the bottom of the 
concavity. 

Anteriorly, in the specimen, the concavity is abruptly intruded upon by a bulging 
of the face, apparently produced by a canine alveolus like that of the Moschus 
moscliiferus and the Dorcatherium. 

Below the concavity of the side of the nose, the face becomes rather abruptly, 
vertically convex; and here, above the anterior fangs of the last temporary molar, 
less advanced than in the Musks, is situated the exit of the infra-orbital canal. 

The anterior and inferior margins of the orbit remain, and show it to have been 
large and subcircular, as in Dorcatheriitm, and to have had a direction outward and 
slightly upward, but apparently not at all forward. The margin of the orbit, 
anteriorly and inferiorly, is everted, and is most jarominent at the lachrymal border. 

The malar bone below the orbit is about three lines deep, and, except its slightly 
everted orbital margin, is vertical in its position, so that its lower border is situated 
considerably exterior to the alveolar processes. That border is nearly on a level 
with the edge of these processes, and the maxillo-malar suture curves ujJward and 
forward from near their edge, about the position of the middle of the last molar 
tooth. Anteriorly to the orbit, the malar bone rises for nearly half an inch above 
its inferior margin, and is there from four and a half to five and a half lines wide. 

The lachrymal bone externally is six lines broad, and forms part of the slope of 
the face converging to the bottom of the concavity at the side of the nose, but pre- 
sents itself no disposition to the formation of a lachrymal sinus. Its orbital face, 
near the margin, is pierced by an infundibular orifice about one line wide to the 
ductus ad nasum. 



POEBROTHERIUM. 21 

The only parts preserved and visible of the base of the cranium, in the speci- 
men, are the auditory bulla), separated by the body of the sphenoid bone. These 
are remarkable for their great size and position. Relatively they are not longer 
than in the Musks, but their transverse and antero-posterior diameters are rather 
greater. They are also more vertical in their position than in the Musks, and 
are so situated that their postero-external portion projects considerably exterior 
to the ramus of the lower jaw, filling up nearly a concavity formed by its posterior 
margin. The length of the bullse from the meatus auditorius is eleven lines, the 
transverse diameter posteriorly nine lines, and the antero-posterior diameter an 
inch. Externally they are convex, and converge forwards within the position of 
the ramus of the lower jaw; internally they are vertical and slightly convex, or 
nearly plane; posteriorly they inclose the stylal pit; and postero-internally they 
present a broad irregular surface, which abuts against the paramastoid process. 
The space separating the bullae, or the width of the sphenoidal body between them, 
is about five lines. (Fig. 1.) 

The auditory process resembles that of the Musks, and the meatus auditorius 
externus, which holds the same relative position as in these, is subcircular, and 
about a line in diameter. 

The glenoid articulation, so fiir as can be ascertained by viewing its position with 
the condyle of the lower jaw in contact, is much like that of the Musks, but 
appears rather more concave. 

Inferior Maxilla. — The form of the lower jaw in Dorcatherium is verj' similar 
to that of the recent Musks, but is very peculiar in Poelroiherium. In this the 
base is much more nearly horizontal, and when placed upon a plane surface touches 
it at the angle and middle, and the anterior portion, which curves downwards from 
the position of the third premolar to the symphysis, also nearly reaches the same 
level. (Fig. 1.) 

The outer surface of the bone below the true molars is convex, but below the 
premolars is nearly plane and deeper than in the former position. The alveolar 
margin rapidly ascends posteriorly from the position of the second true molar, and 
descends in advance of the second premolar. 

The ramus is remarkable for its breadth, and the possession of an angular 
apophysis, as in the Camel, carnivora, and most rodentia. The process in position 
and form is intermediate to that of the Camel and Rabbit. From its point a thin 
convex edge, corresponding to the technical angle, descends to the base of the jaw, 
and a concavity, which in a great measure is occupied by the auditory bulla, ascends 
to the condyle. 

The relation of the condyle and coronoid process is about the same as in the 
Musks, but below the notch separating them, the ramus is depressed relatively as 
much as in the Peccary, a peculiarity in which the genus differs from all existing 
ruminants. 

The condyle externally has nearly the same form as in the Musks, and as far as 
can be seen in the specimen; its articular surface appears to he a little more convex 
than in those animals. 

The coronoid process is relatively broad, and curves upwards as in the Musks. 
4 



22 POEBROTHERIUM. 

Its extremity is broken in the specimen. The symphysis also is broken away, but 
it appears to have commenced from behind about four lines in advance of the second 
premolar, and the anterior mental foramen is situated just above this portion of it. 
De7itition. — I think it probable that the permanent dentition of Foehrotherium 
was equal to the following formula : — 

. 0? 0? 1? 1? 4 4 3 3 on 

^. c. p.m. m. =^ 6b. 

4? 4? 0? 0? ^ 4 4 3 3 

In the specimen, the S3'mphysis with its teeth is broken awaj^; and a portion 
only apparently of the upper canine alveolus remains. 

Superior Molars. — The upper teeth, in the specimen, consist of the three per- 
manent true molai's, fully protruded, and the three temporary molars, forming 
together a closed row, and separated from this by a hiatus with an acute concave 
mnrgin about four lines long, is, what I suspect to be, the first permanent premolar, 
which had no predecessor. (Figs. 1, 3.) 

The permanent true molars resemble those of the Musks, but their constituent 
lobes possess much less prominent summits. The inner lobes also are less angular, 
but more convex internally, and the outer lobes are much less prominent in the 
same direction. The outer lobes of each true molar, in the Musks, are separated 
by a narrow cleft, but in Poehrotherium they are separated only by a longitudinal 
ridge, which is the most prominent of those existing externally. The median 
ridge of each lobe externally is the most prominent and convex in the Musks, 
but is relatively narrow in Poehrotherium, and the intervening spaces are more flat 
in this genus. 

In the specimen under consideration, the last molar had been but a short time 
fully protruded, the enamel being worn only from the summit of its postero-internal 
lobe, and remaining nearly intact upon the postero-external. The summits of all 
the other lobes of the true molars present narrow tracts of exposed dentine sur- 
rounding the interlobular pits of enamel. 

The temporary molars, also, have a very great resemblance to those of the Musks. 
The last of the series is like the permanent true molars, and in the specimen the 
enamel has been worn from the masticating surface, except a small crescentic islet 
between the posterior pair of lolses. 

The second temporary premolar in the specimen has its enamelled triturating 
surface obliterated, and in its present condition is constituted by a wide posterior 
lobe, the result of the confluence of an original transverse pair, and a narrower 
anterior lobe with a pyramidal summit, which does not distinctly appear to be 
formed from the association of an antero-posterior pair, such as exists in the corres- 
ponding tooth of the Musks. Externally this tooth presents three convex promi- 
nences, separated by concave depressions. 

The first temporary premolar has a simple, broad, oblong, trenchant crown, which 
is most prominent at its anterior part. It is convex extei'nally, and the enamel 
internally is worn off in a sloping manner. 

The first permanent premolar, which, as before observed, is removed fi'om the 
others by a hiatus, has a simple oblong, trenchant crown like that last described. 



POEBROTIIERIUM. 23 

but is longest or most prominent at the middle, is convex externally, and sloping 
plane internally, and is inserted in the jaw by two diverging fangs. 

Iiifti-ior Molars. — (Figs. 1, 4.) The lower teeth, preserved in the specimen, consist 
of the permanent true molars, and the three temporary molars. The former are re- 
markable for the simplicity of their lobes, and these, as in the case of those above, 
have not as prominent summits as are found in the Musks. The internal surface of 
their inner lobes is vertical and plane in comparison with what it is in the Musks 
and other ruminants, and its longitudinal ridges are but slightly elevated above 
the intervening spaces. The external surface of these lobes is quite plane and 
nearly parallel with the internal. 

Tiie outer lobes are verticall}^ prismoid witli the anterior surface broader than 
the posterior, and the internal surface more vertical than in the Musks or Deer. 
The extremities of the crescentic summits join the corresponding margins of the 
inner lobes, and there is no disposition to the bifurcation of the posterior horn of 
the antero-external lobes as in the Musks. 

Each trjinsverse pair of lobes, in the specimen, presents a trilateral pit of enamel 
surrounded by a narrow tract of exposed dentine. 

The fifth lobe of the last molar is a simple, thin, enamelled plate, with a trench- 
ant edge. 

The last temporary molar, as in all ruminants, is composed of three pairs of 
lobes; but, in the specimen, from the obliteration of the interlobular enamel pits, 
it rather consists of three antero-posterior prismoid lobes. 

The two temporary premolars, in the broad trenchant character of their crown, 
resemble those of the Musks. Their trenchant margin rises to the middle of the 
teeth, the external surface is elevated into three slight convexities, and the inner 
surfiice is convex posteriorly, but is depressed anteriorly. The margin of the second 
premolar is broadest posteriorly, and is worn off in this position in the specimen, 
and the anterior fifth of the tooth bends within that preceding it. As before ob- 
served, when the specimen was first received, a fragment of the first permanent 
premolar remained in the lower jaw, situated about five lines in advance of the 
first temporary molar. 

This species is named in honor of Dr. Thomas B. Wilson, of Philadelphia, a 
distinguished patron of the natural sciences. 

MEASUREMENTS. 

Inches. Lines. 

Distance from meatus auditorius to anterior part of first permanent premolar . 4 9 

Distance from meatus auditorius to infra-orbital foramen .... 3 1 

Diameter of orbit from lower part of post-orbital arch to lachrymal margin . 1 2 

Bi-eadth at meatus auditorius ......... 1 9 

Breadth at auditory bulla .......... 2 1 

Breadth at malar bone below orbit ........ 2 4 

Breadth at infra-orbitar foramen . . . .*. . . . .1 2 

Breadth above first permanent premolar ....... 7 J 

Breadth above middle true molar ........ 1 10 

Height of orbit from base of lower jaw ....... 1 8 

Height of lower jaw at condyle ........ 1 11 

Height of lower jaw at middle true molar ....... 7 



24 



AGKIOCHOERUS. 



Height of lower jaw at first temporary premolar . 
Height of angular apophysis . . 
Distance from coronoid process to anterior mental foramen 
Length of upper series of six molars .... 
Length of lower series of six molars .... 



Inches. 



Lines. 

7 

10 
4 



GREATEST DIAMETER. 



Antero-posterior. Transverse. 



Seventh upper molar ......... 7 lines. 

Sixth upper molar ......... GJ 

Fifth upper molar 5J " 

Third temporary molar ........ 5 

Second temporary molar ........ 5 

First temporary molar . . . . . • • ■ 4i 

First permanent premolar . . . . . . . .Si 

Seventh lower molar ......... 9 

Sixth lower molar . . . . . . . . . 6J " 

Fifth lower molar 5J " 

Third temporary molar ........ 6 " 

Second temporary molar ........ 5 " 

First temporary molar ........ 4 " 



6 lines. 
5J 
5 
4 

3 ' 
1 ' 
1 ' 
3i ' 



2* " 
1* " 
1 " 



A«R10CH0£RU$, Leidt. 
Ag;riochoeriis antiquum, Leidy. 

(Plate I. Figs. 5-10.) 
Agriochoenis antiqmis, Leidy: Proc. Acad. Nat. Sci.,1850, V. 121; Owen'sRep. of aGeol. Surv.ofWisc, etc., 571. 

Agriochoerus is a remarkable and very peculiar genus of ungulata, representing 
a type which occupies a position in the wide physiological interval existing between 
recent ruminants and the anomalous Anoploiherium. 

It was first established in the Proceedings of the Academy of Natural Sciences 
of Philadelphia, for 1850, upon a portion of a skull, aud several fragments of jaws 
with teeth, received from my friend, Dr. Hiram A. Prout, of St. Louis. 

Of the species characterized under the name of Agriochoerus antiquus, I have 
had the opportunity of studying the following specimens : — 

1. A much mutilated face, with the forehead, and portions of both sides of the 
lower jaw, apparently of an adult individual. The upper jaw contains upon one 
side the posterior five molars, and upon the other side the posterior six molars. 
Both fragments of the lower jaw contain the posterior five molars. The first true 
molar is only slightly worn, while the others have hardly yet been affected by 
trituration. Received from Dr. Prout. (PI. I., Figs. 5-8.) 

2. Two fragments of the upper maxillae, containing each the last two true molars, 
and a fi'agment of the lower jaw containing the anterior two true molars. These 
apparently belonged to the same and an older individual than the former. Received 
from Dr. Prout. (Figs. 9, 10.) 

Descrijjtion of the portion of a Skull. — Viewed from above, the anterior portion of 
the skull is nearly equilateral triangular, the sides of the face converging in a nearly 



AGRIOCHOEEUS. 25 

straight line from the posterior part of the orbit to the most anterior of the molars 
in the specimen. Viewed laterally (Fig. 5), it is remarkable for the lowness of the 
forehead and the parallelism of its npper part with the alveolar margin. 

The forehead is broad, and between the anterior part of tlie orbits is convex, but 
between the jjosterior part, at its middle half, is flat or slightly depressed, and upon 
the post-orbitar processes is rather abruptly depressed. 

The posterior part of the os frontis, in the specimen, has a small fragment of the 
ossa parietalia attached on each side, and between these it is convergent backward 
to wdiere it is broken off, evidently indicating it to have been pointed and received 
into a notch of the parietalia as in the Camel and Merijcopotamus. Anteriorly, 
the OS frontis, though broken, is easily perceived to have terminated in angular 
processes between the ossa lachrymalia and nasi. 

The remains of the frontal suture existing in the specimen, are distinct and zig- 
zag posteriorly, but straight and a little out of the normal course anteriorly. 

About a line on each side of the frontal suture, in a position corresponding to 
the anterior third of the orbit and ten lines from its margin, is a small supra-orbitar 
foramen. 

No portions of the nasal bones are preserved, and the notch of the os frontis, for 
the reception of their posterior extremity, is too much broken to ascertain their 
Umits in this dii'ection, but they appear to have extended a little posterior to the 
position of the airterior orbital margin. 

The orbital entrance is open jDOsteriorly as in Anoplotlicrlum, but is relatively 
larger than in this, and its plane is directed outward and as much upward almost 
as in feline animals; but not so much forward as in the Deer, though rather more 
so than in the Musks. In form it is subcircular, and is about one inch in diameter. 

The post>orbital processes of the os frontis and os mala3 are six lines and three- 
fourths distant from each other, and are thick, compressed, conoidal, and pointed. 
That of the former bone is directed outward and downward, that of the latter 
upward, inward, and slightly anterior, and its point is about four lines external 
to the one above. 

The lachrymal margin is partially broken, but it appears to have been only 
slightly prominent. The facial surface of the lachrymal bone is seven and a 
half lines in vertical diameter, and is a feebly depressed inclined plane, on the 
same level nearly as the orbital entrance. 

The malar bone, compared with that of recent ruminants, is robust, and its 
external face, below the orbit, is vertically slightly convex. Antero-posteriorly it 
is convex, and its anterior limit is on a line with the first true molar tooth. 

The superior maxillary bone, from the position of the malar bone forward and 
upward, as far as it is preserved in the specimen, is prominent and convex, and 
below this upon the alveoli is vertically convex. The infra-orbitar foramen is 
vertically oval and directed forward, and is situated above the hinder fang of the 
penultimate premolar an inch in advance of the orbit. 

The hard palate, for the most part, is obscured by a very hard matrix, to remove 
w^hich would endanger the specimen; but where exposed, between the anterior of 
the premolars, it is remarkable on account of the very great degree of inclination 



20 AGRIOCHOERUS. 

of the two sides; its median suture being about five lines above tlie alveolar 
mai'gin. (Fig. C.) 

Inferior Maxilla. — The two fragments of lower jaw, preserved in connection 
with the specimen just described, and comprising as much of the body of each side 
as contains the hinder five molars, present pretty much the same form as the cor- 
responding portion of the jaw of the Camel, but are relatively deeper and less 
convex externally. (Fig. 5.) 

The alveoli have a remarkable degree of descent forward in relation to the base 
of the jaw; the depth of the bone below the posterior lobe of the last molar being 
twenty-one lines, whilst it is only eleven lines below the last premolar. 

Internally the lower jaw is much more convex than externally, especially in 
advance of the first true molar, and also posterior to this upon the alveolar portion 
of the bone. 

Just above the thick, rounded base of the jaw internally, and below the position of 
the first true molar, a concavity commences, which gradually expands and deepens 
to a line with the posterior lobe of the last molar, when it abruptly increases and 
then continues to the broken margin of the specimen, so that it is probable the 
technical angle of the jaw within is deeply concave, as in the Tapir. 

A little more than half way below the position of the last premolar externally 
is a small foramen directed backward, which is probably an otiset from the inferior 
dental canal. 

Dentition. — The molar teeth of AgriocJioerus are certainly ruminant in their 
type, and the true molars in both jaws are constructed upon the same pattern as 
those of all recent ruminants, each being composed of two symmetrical pairs of 
demiconoidal lobes, with an additional odd lobe to the last lower molar. In the 
specimen above described, the posterior six molars are preserved in the upper jaw, 
and the posterior five in the lower jaw. 

The molars in both jaws successively decrease in size from behind forward. 
Those above, on the two sides, are nearly parallel internally, and from thirteen to 
fourteen lines apart, but externally their line is convergent forward. 

Superior Molars. — (Figs. 5, 6-10.) The upper true molars resemble very closely 
the corresponding teeth of Eijopotaimis deprived of their anterior median or ac- 
cessory lobe. As in this genus, their transverse diameter is greater than that 
antero-posteriorly ; the result apparently of the expansion of the teeth from the 
condition in which they exist in the recent ruminants generally. The lobes are 
low and spread wide apart, and the interlobular spaces are broad and shallow; 
thus the perpendicular height of the outer lobes of the last molar is four lines, 
and the distance between the summits of the anterior pair of lobes is three lines. 

The outer lobes conjoin externally to form a prominent median convexity, and 
another, similar but not quite so large, is formed by the union of the anterior angle 
of the antero-external lobe with the contiguous prolonged ai'm of the summit of the 
antero-iutcrnal lobe. The surface of the outer lobes, between the external con- 
vexities, is transversely concave with the feeblest degrefe of median elevation, .and 
inclines very much inward. Internally the outer lobes are convex and nearly 
vertical. 



AGRIOCHOERUS. 27 

The inner lobes are smaller than those external, are convex internally, and con- 
cave externally with a slight median elevation. The extremities of the summits 
extend around tlie base internally of the outer lobes, except that posterior of the 
antero-internal lobe, which ceases abruptly at its arrival in the transverse valley 
of the tooth. 

Constituent portions of a basal ridge, feebly developed, exist principally between 
the bases of the inner lobes, and anteriorly and posteriorly. 

The fourth premolar is quite peculiar, and rather resembles a last deciduous 
molar than the permanent premolars of ordinary ruminants. It consists of two 
pairs of lobes like those of the true molars, but the postero-internal lobe is in a 
rudimentary condition, consisting of a small pyramidal tubercle occupying the 
normal position. The prominence externally produced by the confluence of the 
outer lobes is relatively not so large as in the true molars, but otherwise the prin- 
cipal lobes have the same form. 

The third premolar consists of one large trihedral pointed lobe, with a rela- 
tively small pyramidal lobe, situated at the base of its postero-internal face. The 
latter lobe is broken in the specimen. The external face of the former is the 
broadest, is slightly convex, and is prominent in the median line. The inner faces 
are sloping, and that posteriorly is concave. 

The second premolar has nearly the same form as that last described. Its prin- 
cipal lobe is relatively less broad, and its external face is more convex. A rudi- 
mentary lobe, which apparently existed at the base of the postero-internal face of 
the principal lobe, is broken away in the specimen. 

The upper true molars are implanted by four fangs; the last premolar by three; 
and those in advance by two. The fangs of the anterior premolars, and the outer 
ones of the last premolar and the true molars, present a remarkable curve outward 
in their course downward. 

Inferior molars. — (Figs. 7-9.) The outer lobes of the lower true molars are larger 
than those within, but do not rise quite so high. Their internal face is concave and 
slightljr elevated in the median line. Externally they are conoidal, are confluent 
at the base, are without intervening portions of a basal ridge, and are slightly 
spread outwardly towards their lateral margins. 

The anterior extremity of the summit of the antero-external lobe joins the con- 
tiguous margin of the lobe within ; its posterior extremity in association with that 
anterior of the summit of the postero-extei'nal lobe turns upward and becomes con- 
fluent with the posterior part of the external face of the antero-internal lobe; and 
the posterior extremity of the postero-external lobe, except that of the last molar, 
bifurcates, one portion connecting itself with the posterior part of the outer face of 
the postero-internal lobe, the other with the posterior margin of the same lobe. 

The inner lobes externally are convex and nearly vertical, and internally are 
most prominent in the median line, and have their angles everted into short, promi- 
eut, divergent folds. 

The fifth lobe of the last molar is about the size of those external, and in section 
is oval. Its pointed summit descends by a pair of U like arms, one of which joins 



28 



AGllIOCHOERUS. 



the margin of the internal of the posterior pair of lobes, the other the contiguous 
extremity of the summit of the inner of the same pair of lobes. 

The fourth premolar, like the true molars and the corresponding tooth of the 
upper jaw, also has four lobes. Those external have the same form as in the true 
molars, but that anterior is larger than the one posterior. The inner lobes are 
reduced representatives of those homologous in the true molars, and still preserve 
the same form, but as they retain their connection with one another, they are 
placed at the posterior three-fourths of the position of the tooth. 

The third premolar is formed by a single, large, broad, demiconoidal crown, in 
which, however, may be traced a constitution of two outer lobes corresponding to 
those of the true molars, the posterior of which has become almost entirely fused 
with the anterior, but is still distinguishable by a depressed line externally, and a 
well marked cul-de-sac internally. 

All the inferior molars have two fangs, and in the last of the series the posterior 
consists of a confluent pair. 

The enamel ujion the teeth described is everywhere smooth, or is only very 
slightly corrugated. 



MEASUREMENTS. 

Breadth of face from oue lualar bone to the other, posterior to the orbits 
Breadth of forehead at post-orbital processes of os frontis 
Distance between the infra-orbital foramina .... 

Diameter of the orbits ....... 

Height of forehead above the alveolar margin 

Distance between the posterior molars anteriorly . 

Distance between the third premolars . 

Length of line of the posterior six superior molars 

Length of line of the five inferior molars .... 

Length of line of superior true molars ..... 

Length of line of inferior true molars ..... 

Greatest autero-posterior diameter of the posterior superior molar 

Greatest transverse diameter of the posterior superior molar . 

Greatest height of the posterior superior molar 

Greatest antero-posterior diameter of first superior true molar 

Greatest transverse diameter of first superior molar 

Greatest antero-posterior diameter of fourth premolar 

Greatest transverse diameter of fourth premolar . 

Greatest antero-posterior diameter of second premolar 

Greatest transverse diameter of second premolar . 

Height of the second premolar .... 

Antero-posterior diameter of posterior inferior molar 
Transverse diameter of posterior inferior molar 
Antero-posterior diameter of first true molar 
Transverse diameter of first true molar 
Antero-posterior diameter of fourth premolar 
Transverse diameter of fourth premolar 
Antero-posterior diameter of third premolar . 
Transverse diameter of third premolar . 



Inches. 


Lines 


4 




2 


4 




6J 








10 




2 




2 


3 




3 




1 


10 


2 


U 




9 




lOJ 




3i 




7i 



4i 

3 

3J 

6 

6i 

4J 

6i 

4 

4J 

3 



OREODON. 29 



OREODOIV. 



(Plates II.— VI.) 

In the Proceedings of the Academy of Natural Sciences of Phihidelphia for 1848, 
I described two fragments of an upper and a lower jaw of an extinct ungulate animal, 
from the Bad Lands of Nebraska Territory, presented to the Academy by Mr. 
Alexander Culbertson. The fragment of an upper jaw contained the last two 
molars, that of the lower jaw the three true molars, and from the form of the teeth 
I characterized the animal under the name of Merycoklodon Culhertsonii. 

In 1851 I received from the Smithsonian Institution, and from Dr. Hiram A. 
Prout, of St Louis, several fragments of skulls and jaws, obtained from the same 
locality as the former. These contained the same form of true molars; but, being mis- 
led by a fragment of the face of a young animal containing a portion of the first 
permanent premolar, followed by the entire first, and portions of the second and 
third deciduous molars, in a verbal communication to the Academy,^ I referred 
the specimens to two other distinct genera, to one of which the name Oreodoa 
was given, and to the other that of Cotylops. 

All these have since been satisfactorily determined to belong to a single genus, for 
which I desire to retain the name Oreodon, in preference to Merycoidodoii ; for all 
the anatomical characters of the animal indicate it to have been a true ruminant, 
and not merely like one in the form of its molar teeth. 

Oreodon is a remarkable and very peculiar genus of ruminant ungulates, constitut- 
ing one of the links necessary to fill up the very wide gap between existing rumi- 
nants and that exceedingly aberrant form of the same family, the extinct AuojjIo- 
iherium of Europe and Asia. 

Of this genus I have been enabled to examine crania, more or less perfect, and 
fragments of others; and teeth of numerous individuals of at least two, and probably 
three distinct species, and can render our knowledge of the head of the animal 
almost complete. 

Description of dlie Skull. — The form of the skull of Oreodon is so peculiar that I 
know of none among existing ungulates with which to compare it nearer than that 
of the Camel; and yet this only approaches it in the form of the cranium proper. 
Generally it has most resemblance to that of Anoplotherlum, but from this it strik- 
ingly diflfers, in the existence of post-orbital arches as in all existing ruminants; ui 
tlie greater size of the orbits; in the presence of deep lachrymal depressions, rela- 
tively as large as those of the Deer or of the extinct Bootheriam ; and in other 
important particulars. The true molar teeth are decidedly of a ruminant cha- 
racter; while canines and incisors exist in both jaws, and form with the molars 
almost unbroken rows, as in Anophtherium. 

Lateral View.—{Fl II. Figs. 1, 3; III. 2 ; V. 1; VI. 3, 4, 6.) The side view of 



' Proc. Acad. Nat. Sci., V. p. 237. 



30 . OREODON. 

the skull resembles in its general form very much that of AnoplotJiermm . The 
upper outline of the skull forms an almost unbroken convexity from the inion to 
the end of the nose ; being depressed very slightly only upon the forehead at the 
bifurcation of the sagittal crest. The outline of the inion is obliquely downward 
and forward, and is only intruded upon by the occipital condyles. 

Among existing ruminants, the cranium proper of Oreodon is very like that of the 
Camel and Llama. As in these, the temporal fossa is large and extends superiorly to 
the median line of the skull, where it rises upon a prominent sagittal crest, which 
posteriorly, in conjunction with the occiput, forms an eminence projecting above the 
inion and constituting its summit. The fossa at the margin of the inion forms an 
oblique crest, which relatively is not as deep as that of the Camel, and which is 
constituted by the junction of the squamous portion of the temporal bone Avith an 
elongated process from the pars petrosa intercalated between the former and the 
occiput; and above by the occiput alone. Anteriorly the fossa is bounded by the 
divergent portion of the sagittal crest upon the post-orbital process. 

The temporal surface generally is smooth and convex, but is concave along the 
course of the occipital crest and the sagittal crest posteriorly, and as in the Camel, 
nearly one-half of its extent is constituted by the squamous portion of the tem- 
poral bone. 

Following the course of the squamous suture at its anterior part, in some of the 
crania, the parietal bone is depressed into a groove, resembling the impression 
of a bloodvessel, or the trochlea of a tendon; but in other specimens this groove 
does not exist, or is very slight. At the back part of the same suture, varying in 
position in different individuals, are one or two vascular foramina, directed upward 
and backward. (V. 1.) 

In all the specimens under investigation the zygomatic arch is broken ; but, 
judging from a portion remaining in the skull of an immature animal, it is rela- 
tively as strong as in the Camel. (VI. 6.) 

The malar bone, as in the Deer, has a much more anterior position than in the 
Camel, but it is more robust than in this, and its outer surface is convex and on 
the same plane with the entrance of the orbit, being directed forward and upward. 
Anteriorly, it is continuous with a- corresponding swell of the face, converging 
forwai'd above the alveolar processes. 

The post-orbital process of the os frontis combines with that of the malar bone, 
so as to form a complete post-orbital arch, such as exists in all recent ruminants; 
which is relatively stronger than that of the Deer, Ox, or Sheep, but is not- quite 
as strong as in the Camel. (IV. 3 ; VI. 4, 6.) The temporal attachment extends 
upon the post-orbital arch, as far as the transverse suture. 

The entrance of the orbit is sub-rotund, and is directed to about the same extent 
forward as in the Deer, but in a slight degree more upward. (IV. 3.) 

The face, in its general form, strongly resembles that of Anoplotlierium ; and 
in comparison with that of the Deer, not only appears to be shortened to an extent 
corresponding with the vast hiatus existing anterior to the molars in the latter, but 
also to recede; for, the last molar is on a line vertical to the post-orbital arch, as 



OKEODON. 31 

in the Camel and Anoploiherium ; whereas, in the Deer, and other ruminants, it is 
beneath the anterior part of the orbit. (II. 1, 2.) 

Internal to the position of the malar bone, the face is deeper than in Anoplothe- 
rium, but relatively is not as deep as in the Camel. 

The infra-orbitar foramen is placed above the position of the third premolar, and 
is more advanced than in the Anoplotherium or Camel, but is less so than in the 
Deer, Ox, Sheep, and other ruminants. The face, from the post-orbital arches to 
the nose, constitutes very neai'ly an equilateral triangle, being relatively broader 
between the post-orbital arches, or at the base of the triangle, than in Anoplotlie- 
rium. The side of the face, in advance of the orbit, is vertically convex, and 
one of the most remarkable features of the genus exists upon this surface, viz., a 
large lachrymal depression gradually gommenciug at the borders of the bones in 
sutural connection with the lachrymal bone. This depression is rather more 
elevated in its position than in the Deer, and is hemispherical, as in the extinct 
genus of pliocene Oxen, the Bootherium. Anterior to the infra-orbitar foramen 
the face is slightly depressed, and just in advance of this position is a gentle rise, 
corresponding to the coui'se of the fang of the canine tooth. 

The lateral view of the exti'emity of the nose resembles more that of the Anoplo- 
ilierium than of any existing ruminants, presenting the same slope lateral to the 
convex termination of its floor, which is constituted by the incisive alveoli. The 
intermaxillary bone, however, is very much smaller than in this genus, projecting 
as it does at the lateral margin of the nose only very slightly beyond the end of 
the maxillary, and at the incisive alveoli a very small distance relatively beyond 
the anterior line of the canine tooth. (II. 1.) 

Superior View. — (PL IV. Fig. 1 ; V. 4 ; VI. 1.) The upper view of the cranium 
proj)er, much resembles that of the Camel. The sagittal crest is prominent, and 
pyi'amidal, with concave sides; and it bifurcates immediately at the position of the 
coronal suture. The forehead generally is convex; and it has very neax'ly the 
form of that of the Camel, but it is less prolonged outwardly towards the orbits, and 
is not so prominent above these, and also is relatively not quite so much depressed 
at the bifurcation of the sagittal crest. 

The supra-orbitar foramen varies in its exact position in different individuals, but 
is usually situated a short distance from the frontal sutui'e, and nearer to the fronto- 
nasal, than to the coronal suture. It is directed forward, and is continuous with a 
shallow groove passing to the outer side of the fi'onto-nasal suture. (IV. 1.) 

The muzzle is relatively short, as in Anoplotherium, and superiorly is usually 
transversely convex, with the sides vertical; but in some specimens it is nearly flat 
at the nasal bones. 

As far as can be ascertained in any of the specimens, but principally from an im- 
pression upon a portion of matrix, the anterior extremity of the nose, as constituted 
by the ends of the ossa nasi, appears to have been like that of the Deer; and the 
lateral margin and incisive alveoli are convex; and the latter project relatively 
to their position in Anoplotheriu7n, or recent carnivora, very little beyond the front 
of the canines. 

Posterior Vieiv. — (PI. IV. Fig. 2.) The occipital surface resembles a good deal 



32 OREODON. 

that of Anoplotlierium. Its median portion bulges backward above the foramen 
magnum, and is concave below the summit of the inion. The lateral portions of 
the surface are directed outwardly from the median, and are moderately concave, 
but relatively much less than in the Camel. 

The lateral margin of the inion, or the occipital crest, is relatively less prominent 
than in the Camel; and at its lower part is formed, as in the Doer and other rumi- 
nants, by the elevated border of the pars squamosa and a process of the jiars petrosa 
intercalated between the former and the occiput. 

The occipital foramen is transversely oval and emarginate above.. 

The condyles resemble those of the AnojjloiJiermm, and do not advance upon 
the basilar jDrocess inferiorly as in the Camel, Deer, and other ruminants. Their 
position corresponds pretty closely with that which they have in the Camel; and 
their angle and superior and inferior faces present in the same direction. 

Inferior View.— (PI. III. Fig. 1; V. 2, 3; VI. 3.) The base view of the skull, 
in its general form, much resembles that of Anoplotherium ; but it is relatively 
broader in comparison with its length, and presents numerous peculiarities. The 
basilar process slopes on each side from a central crest, which expands at the con- 
dyles and at its junction with the post-sphenoidal body. The surface of the latter 
is smootli, slightly convex, and inclines slightly upward in its direction forward. 
(III. 1; V. 2.) 

The pterygoid processes commence a little in advance, and to the outside, of the 
position of the spheno-basilar junction, and are very oblique in their course down- 
ward and forward. To their inner side iS a shallow groove, directed to the foramen 
lacerum, for the reception of the Eustachian tube. 

The i^aramastoid processes form the infero-lateral terminations of the occiput, and 
are conspicuous objects either in the lateral or posterior view of the skull. They 
are relatively about as long and strong as those of Anoplotherium, but are nearly 
vertical, or bent slightly forward and outward. Their form is elongated pyramidal, 
and the outer portion of their base abuts upon the posterior process of the pars 
petrosa, as in the Deer ; while the antero-internal portion rests upon the auditory 
bulla. Antero-externally the para-mastoid process is longitudinally excavated, and 
between its base and the pars petrosa it incloses the stylo-mastoid foramen, and in 
advance of this the pit of reception for the styloid process. (III. 1; V. 2.) 

The mastoid process is small, as in all ruminants, and is a compressed eminence or 
ridge forming the posterior boundary of the meatus auditorius externus. It does not 
descend as low as the bottom of this, and projects between the auditory process 
from which it is separated by a notch, and the base of the paramastoid process. 

The auditory process constitutes the antei'o-inferior boundary of the meatus, and 
inferiorly forms a ridge-like vaginal process curving forward and inward to the 
auditory bulla with which it is continuous. 

The latter is relatively very small to what it usually is in ruminants, and cor- 
responds in this respect with Anoplotherium. It is convex, surmounted by the ridge 
just indicated, rests against the paramastoid process posteriorly, and is continuous 
with the bony process of the Eustachian tube anteriorly. Internally, as in existing 



OllEODON. 33 

ruminanti?, the pars petrosa borders a largo irregular excavation, constituting the 
foramen lacerum postcrius, and anterius, and a portion of the Eustachian tube. 

Immediately posterior to the foramen lacerum, and internal to the base of the 
paramastoid process, the hypoglossal or anterior condyloid foramen is situated. 

The foramen ovale holds the same relative position as in recent ruminants, being a 
little to the outside of the commencement of the pterygoid processes, and in advance 
of the bony process of the Eustachian tube. 

The glenoid articulation, one of the most important features of the cranium in 
reference to the habits of the animal, is broad as in existing ruminants, is slightly 
convex anteriorly and concave posteriorly ; and in this position is bounded by a 
inammillary post-glenoid tubercle, which is compressed autero-posteriorly, and is 
relatively very large and robust. This tubercle is a very conspicuous object in the 
lateral view of the head, and projects below the auditory process and bulla. Between 
it and the auditory process is a narrow fissure, and at the bottom of this internally 
is the glenoid foramen. 

Antero-internally, the glenoid articulation is prolonged upon a broad surface for 
muscular origin, formed by the conjunction of the post-sphenoid and pars squamosa, 
and terminating anteriorly in a pyramidal eminence, as in the Deer. 

The pterygo-palatine notch is long and narrow, and extends as far forward as 
the posterior third of the last molar. Its margins are thick, strong, and rounded. 

The notch extending between the palate bone and the tuber maxillare is almost 
as deep as that of the Deer, but is more angular. It terminates on the same line 
nearly as the pterygo-palatine notch, as in the Sheep. 

The hard palate is slightly arched, and deepens iu an angular manner towards 
the centre. In some of the specimens it deepens very much, and in others not 
more than in the Deer in advance of the molars. Its lateral margins, coi'respond- 
ing with the alveoli, are nearly parallel throughout the course of the molar series. 

The posterior palatine foramina are pierced in the palate plates of the superior 
maxillary bones on a line with the fourth or third premolars. 

The position of the incisive foramina, as far as can be ascertained from the imper- 
fect specimens, appears to be on a line with the canine teeth. 

Orbits. — (PI. IV. Fig. 3; VI. 4, 6.) As before observed, the entrance of the 
orbit is subrotund and directed outward, and a little forward and upward. Its 
margin is less prominent than in the Deer, and at the inner canthus is elevated 
into a vertical, slightly sigmoid, compressed mammillary, lachrymal process. The 
inner wall of the orbit is more oblique in its course backward to the optic foramen 
than in the Deer, and the alveoli contribute more to its floor, which is deep and 
concave. 

The entrance to the infra-orbital canal is a broad oval orifice at the lower part of 
the front of the orbit, formed below by the alveolar processes and above by the 
lachrymal and palate bones. 

The lachrymal foramen is vertically oval, and contracted at its lower part, and 
is situated just within the lower part of the lachrymal process. Near it externally 
is a small round foramen. 



34 OIIEODON. 

At the inner side of the entrance of the infra-orbital canal, are two foramina, 
homologous with the posterior palatine and spheno-palatine foramina. 

Another foramen, the anterior orbital, is situated in the suture between the 
lachrymal and palate bone, about half way between the entrance to the infra-orbital 
canal, and the lachrymal margin of the orbit. 

The foramina spheno-orbitale and rotundum, form one large and vertically oval 
foramen, which is situated just within the pyramidal process forming the terminal 
conjunction of the temporal and pterygoid surfaces. 

The optic foramen is situated some distance in advance of, and slightly above 
the position of the spheno-orbital, is about one-third the size of the latter, and is 
also vertically oval. • 

The bones which contribute to the construction of the orbit are the lachrymal, 
frontal, superior maxillary, malar, palatal, and anterior sphenoid. 

Form, Relations, and Connections of the Bones of the Skull. — The occipital bone 
posteriorly, is trilateral with a prominent apex, and it terminates by its other angles 
in the long paramastoid processes. 

The lambdoidal suture commences at the outer side of the base of the latter, and 
ascends posteriorly between the occiput and the process from the pars petrosa, and 
then advances over the occipital crest to the side of the cranium between the occipital 
and parietal bones. It is serrated, and at the occipital summit it forms a trifoliate 
line. 

The spheno-basilar connection is not obliterated in the adult specimens under 
investigation, but is elevated and distinct. 

As in the Camel, the squamous portion of the temporal bone, from its great 
relative size to that of most other animals, is a striking feature in the anatomy of 
the temporal fossa. 

The squamous suture forms about three-fifths of an oval outline, and is pretty 
strongly serrated as in ruminants generally. 

Between the pars squamosa and the occiput posteriorly, is a narrow process from 
the pars petrosa, ascending from between the mastoid process and the base of the 
paramastoid, to the conjunction of the occipital with the parietal bones. To the 
pars squamosa and occiput, it is connected by serrated suture. 

As in all ruminants, there is only a single parietal bone; and, as in the Camel, 
this is remarkable for its length in comparison with that of more ordinary mem- 
bers of the family. It is narrowest posteriorly, and gradually widens to the ante- 
rior portion of the squamous suture, where it descends to the wings of the post- 
sphenoidal bone. Anteriorly it is deeply notched for the reception of the posterior 
part of the ossa frontis. 

The body of the post-sphenoidal unites with that of the ante-sphenoidal on a 
line with the spheno-orbital foramina. 

The wing of the ante-sphenoidal bone articulates with the vertical plate of the 
palate bone, the frontal, a small portion of the parietal, and the wing of the post- 
sphenoidal bone. 

The external pterygoid process is united with the internal, as in the Sheep and 



I 



OREODON. 35 

other ruminants; but it is very much more oblique in its course than is usual in 
these, and even more than in the Sheep. 

The internal pterygoid process shows itself as in recent ruminants, at the pos- 
terior extremity of the orbit, between the vertical plate of the palate bone, the 
external pterygoid process, and the wing of the post-sphenoidal bone. 

The frontals remain separated in the adult condition, and are relatively shorter 
than those of ordinary ruminants. They commence in an angular manner poste- 
riorly, and expand rapidly forward and outward to the post-orbital margin, as in 
the Camel, and then converge forward, the supra-orbital margins being nearly 
straight, and terminate in angular processes which advance beyond the ossa lac- 
rymalia. Anteriorly they form a deep notch, extending nearly to a line with the 
anterior orbital margin, for the reception of the posterior extremities of the ossa nasi. 

The forehead, as constituted by the ossa frontis, ordinarily is prominent and con- 
vex above the orbits, and slightly depressed along the median line or course of the 
frontal suture. The orbit presents more upward than in recent ruminants, and 
the post-orbital j^rocess in its descent to join the malar bone is directed more out- 
ward; and it also is directed backward, as in the Camel, though not to the same 
relative extent. The nasal bones, anterior to the angular processes of the ossa 
frontis, are of nearly uniform breadth, are slightly convex, and incline more or less 
outwardly. 

The lachrymal bone/orms two sides of an irregular cuboidal figure, with the 
facial side dej^ressed into a deep hemispherical lachrymal sinus. The two 
sides are sub-equal, and their angle of union constitutes the anterior orbital 
margin. Inferiorly the orbital side forms the supero-external boundary of the 
entrance to the infra-orbital canal; and postero-internally it is deeply notched for 
the reception of the upper extremity of the palate bone. 

As in recent ruminants, the lachrymal bone articulates with the os frontis, os 
maxillare, os mate, and os palati; and it is separated some distance from the os nasi 
by the advance of the angular process of the os frontis. 

The palate plates of the ossa palati advance as far as the position of the first 
true molar, and in some specimens, to the interval between the latter and the fourth 
premolar. The vertical plates are shallow, but relatively broader than those of 
recent ruminants. 

In the orbit, the palate bone forms the internal boundary of the entrance to the 
infra-orbital canal, and is pierced internal to this by the posterior palatine canal, 
and the homologue of the spheno-palatine foramen. It articulates with the maxil- 
lary, the frontal wing of the anterior sphenoid, the anterior margin of the internal 
pterygoid process, and the exti'emity of the external pterygoid process. 

The superior maxillary bone, compared with that of recent ruminants, is not as 
short as might .be supposed ; for the space in these which constitutes the hiatus 
anterior to the molar series, is in Oreodon occupied by a molar additional to the 
ordinary functional numbei', together with a well-developed canine ; leaving a little 
vacancy for the accommodation of an inferior canine. Its outer side is vertically- 
convex, but is depressed in advance of the infra-orbital foramen. 

The suture between the maxillary, and malar and lachrymal bones, ascends in 



3G OEEODON. 

an irregular oblique line from the antero-inferior angle of the malar bone, opposite 
the position of the second true molar, to the angular process of the os frontis at some 
distance posterior to its termination. 

The malar bone below the orbit externally, presents a single, smooth, convex 
surface, slightly directed upward. Its inferior margin is thick, strong, and rough- 
ened; and its posterior extremity beneath the position of the post-orbital arch, is 
deeply notched for the I'eceptiou of the anterior extremity of the zygomatic pro- 
cess of the temporal bone. 

The intermaxillary bone, compared with that of recent ruminants, or of the Anoplo- 
therium,, or even with that of carnivora, is very small but strong. Its upper extre- 
mity is received into a notch of the maxillary bone, and does not come into con- 
tact with the nasal bone. 

Liftrior Maxilla.— (PI II. Figs. 1, 3; IV. 4 ; VI. 4, 6.) The lower jaw is inter- 
mediate in its form to that of the extinct Aiioplotherium and the common Hog, 
except that the alveolar margin, at its anterior extremity, is not everted as in the 
latter, but retains the upward direction, as along the course of the molar alveoli. 

The body of the bone, compared with that of the Deer, is relatively deep, and 
its base pursues a less sigmoid course, and is very like that of Anoplotherium Its 
outer side is vertical, and very slightly convex, but anterior to the mental foramen 
is convex forward, or rapidly convergent to the symj)hysis. Its thickest part is 
along the line of the latter, and that of the alveoli. 

The symphysis is deep, and forms a strong slope; but it approaches the vertical 
line much more than in the Anoplotherium, or than in the Hog. Its lower part, or 
the posterior mental tubercle, is on a line perpendicular to the second jjremolar, or 
in some specimens to the interval between this and the third. 

The alveolar margin ascends so rapidly jjosterior to the last premolar, that the 
body of the lower jaw behind the last molar, is deeper by more than half than it 
is below the former tooth. 

The ramus is relatively as broad as in the Hog, but is more vertical and convex 
upon its outer face. It is relatively deeper than in A)Loplotlierium, but is less pro- 
duced backwards than in this, and more so than in the Hog. The posterior mar- 
gin is thick and convex, and projects externally into an irregular ridge for the 
masseteric attachment. The inner side of the ramus inferiorly presents a concavity 
which converges forward below the molar alveoli. Below the notch separating 
the condyle and coronoid process the external surface presents a depression in form 
like that of the Peccary, but deeper, in the possession of which Oreodon difiers 
from all recent ruminants. 

The coronoid process, in comparison with that of the latter, is remarkable on 
account of its shortness, being relatively not longer than that of the Hog, which it 
also resembles in form and relation to the condyle. The latter is a transverse 
convexity, very slightly inclining downward within, and possesses about the same 
extent and form as in the Peccary. 

The anterior mental foramen is placed below the second premolar, or the interval 
between it and the first. Not unfrequently there is a second, or even a third, but 
smaller foramen, situated at variable distances posterior to the principal one. 



OREODON. 37 

Dentition. — The dentition of Oreodon is remarlcably distinct from that of any 
living or auy known extinct genus, and it indicates the combined habits of ruminat- 
ing and suilline animals, or, in other words, it appears to characterizs a ruminating 
hog. 



The formula of the permanent dentition is as follows : — 
3 3 11 4 4 



%. c. p.m. - — m. 



44. 



44 11^ 33 33 

The true molars are constructed after the type of those of recent ruminants; the 
premolai'S approach most, among recent animals, those of the deer tribe ; the canines, 
those of the peccaries; and the incisors occupying both jaws, in this relation among 
living ruminants, find their nearest representative in the camel tribe. 

Rdative Position of the Teeth. — (PI. II. — VI.) The upper molars, internally, are 
nearly parallel vipon the two sides of the jaw, but externally they are convergent 
forward from the second true molar, by reason of the gradual decrease in size of 
the teeth in advance of this. Viewed laterally, they present a convexity down- 
ward rather greater than that in the Deer. 

Each true molar, at its antero-external margin, projects exterior to, and a little 
in advance of the contiguous margin of the preceding to(;th, as among existing rumi- 
nants, in Anoplotherium, Bhinocerofi, etc. 

The fourth premolar, and in some specimens the third, project at their antero- 
external margin exterior to tlie outer face of tliose preceding, but never in advance 
of this point. 

The second premolar, on the contrary, has its anterior margin a little within the 
position of the first, as if this had been pushed backward and outward to form the 
small hiatus existing between it and the canine. 

The face increases slightly in breadth in advance of the premolars ; apparently 
for the accommodation of the canines, which, at the base of their crowns, project 
one-third their transverse diameter exterior to the first premolar. 

The hiatus existing between the upper first premolar and the canine, is only 
sufficiently large to receive the point of the inferior canine. Between the upper 
canine and the incisors there is usually, but not in all the specimens, a hiatus 
smaller than the former, adapted to the accommodation of the outer angle of the 
crown of the large lateral incisor below. 

The superior incisors are arranged in the arc of a circle greater than in the Wolf, 
and they project vertically downward, and very little in advance of the position of 
the canines. 

The inferior molars of the two sides are internally nearly parallel ; and are 
much more nearly so externally than the upper molars, from the breadth of these 
being less uniform. Viewed laterally, the triturating surface of the former presents 
a concavity corresponding to the convexity of the series above. 

The relation of the true molars and of the third premolar to one another, is the 
same as in existing ruminants. The anterior margin of the second premolar is 
placed within the position of the first, and the corresponding portion of the latter 
holds the same relation to the canine ; apparently as if these teeth had been pushed 
outward and backward in a jaw, in which little space could be spared to form, ante- 



38 OREODON. 

rior to the lower canine, a hiatus of sufficient size to accommodate the cusp of the 
upper one. Tliis hiatus is in a trifling degree less than that posterior to the upper 
canine. 

The inferior incisors are oblique in their position, but relatively, less so even than 
in the Musks ; and they form a longer arc of a lesser circle than those of the upper 

When the jaws are closed, the inferior molars are situated within the line of the 
outer lobes of the upper true molars, but anteriorly they are placed very little within 
the outer faces of the upper premolars. 

The intervals between the jjyi'^ii'idal crowns of the premolars are triangular, 
and the three inferior crowns are included by the four superior ones. 

The crown of the superior canine is directed downward and outward, and, as 
in the genus Palccotherium, it is placed in advance of the canine below; a position 
which is exceedingly anomalous. Its point projects considerably exterior to the 
inferior canine, and only its internal angular margin occupies the hiatus in advance 
of the latter tooth. 

The crown of the lower canine is directed upward, and a little forward and 
outward ; and its point, though projecting slightly exterior to the hiatus provided 
for it above, is yet within the line of the outer surface of the upper canine. 

The inferior incisors, laterally, are included within the circle of the superior; 
while the cutting edges of those anterior come in contact with the edges of the 
corresponding teeth above. The outer sides of the upper incisors are vertical, and 
those of the lower incisors incline to them at an angle of about 50°. 

Saperior Molars.— {V\. II. Figs. 1, 3 ; III. 1, 2 ; IV. 6 ; V. 2, 3 ; VI. 2, 3, 4, 6.) The 
crowns of the upper true molars are composed of four symmetrical lobes, as in all 
existing ruminants. Among these, they approach most in their form the crowns 
of the corresponding teeth of the Deer, but they are more expanded trans- 
versely, and more square, the interlobular depressions more shallow, and the 
inner lobes are uiicomplicated with accessory folds or lobes. Among the extinct 
ruminants of which we have any knowledge, they resemble most those of 
3Ierijcopotamus ; but they differ from the teeth of this genus in a number of par- 
ticulars, more esjjecially in the non-isolation of the outer lobes (which conjoin 
in a prominent buttress, as in Anihracotherium), and in the relatively slight degree of 
development of the basal ridge, which does not traverse the bottom of the trans- 
verse interlobular space, as it does in the Merycopotamus. . From the corresponding 
teeth of Antliracotlierium, Hijopotamus, and CaenotJieriwm, they differ most, in the 
absence of the fifth constituent lobe, which in the former two genera is introduced 
between the anterior pair of normal lobes, and in the last genus between the poste- 
rior pair. From those of Dlcliodon, they differ in the absence of the curiously 
cuspidate basal ridge, and in the less acuteness of the lobes. Finally, from the true 
molars of the most aberrant forms of extinct ruminants, the Anoplotherium and 
CJialicotherium, they differ as characteristically as do those of any of the existing 
members of the ftimily. 

When unworn, the lobes of the true molars have acute crescentic summits 
elevated to a middle point. The outer lobes anteriorly, and consequently 



OREODON. ' 39 

where they conjoin in each tooth, form prominent columns, not robust and con- 
vex, as in Hijopotamus, but antcro-posteriorly compressed and rather aljruptly ex- 
panded near the base of the crown, where they are more or less connected by 
intervening portions of a basal ridge. In some specimens, however, this ridge is 
obsolete, more especially at the postero-external lobe. (II. 1, 3 ; III. 1, 2.) 

In two specimens under investigation, the basal ridge externally is well develojied, 
strong, and rough at tlie margin ; and it exhibits a tendency to extend itself on the 
outside of the projecting columns, as is indicated by a roughness of the enamel. 
(HI. 1, 2.) 

As in all ruminants, there is a disposition in the postero-extemial lobe of the 
molars to form a posterior column or fold, which, however, to a great extent, 
except in the case of the last molar, remains aborted ; and which, in the external 
view of the jaw, is concealed by the anterior column of the antero-external lobe. 

The outer faces of the external lobes of the molars between the columns are 
transversely concave, slightly prominent in the median line ; and they incline at an 
angle of about 40°. The inner faces are nearly vertical, but they incline slightly 
outward, and are angularly convex. • 

The internal lobes appear broader transversely than the external, because their 
outer face becomes confluent at the basal third of the inner face of the latter. 

The outer face of the internal lobes is concave, and very slightly prominent in 
the median line; and it inclines to about the same extent as the corresponding 
surface of the external lobes. The inner faces are not quite as angular in their 
convexity as those of the external lobes. 

The summits of the latter are confluent at the apex of the median outer column, 
but those of the internal lobes are not confluent. The anterior extremity of the 
summit of the postero-internal lobe ceases abruptly, and it is included between the 
anterior half of the inner face of the postero-external lobe, and the posterior extre- 
mity of the summit of the antero-internal lobe, which latter extremity bends for- 
ward to the posterior part of the inner face of the antero-external lobe, and then 
terminates abrujDtly. 

Portions of a basal ridge, which are sometimes more or less excavated, and have 
an irregular crenulated margin, usually exist at the bases, anteriorly and poste- 
riorly, of the internal lobes. Occasionally they are continuous around the base of the 
postero-internal lobe of the second and third true molars, but more frequently upon 
the latter alone than upon both. Between the lobes internally, the ridge sometimes 
forms a single tubercle, simple and obtuse, or excavated. 

In the trituration to which the true molars are subjected in mastication, the 
summits of the anterior lobes suffer at first more than those of the posterior, and 
the internal more than the external; but, in course of time, the abrasion is nearly 
equalized over the grinding surface. 

When the dentinal substance is first exposed by the removal of the enamel 
summits of the external lobes, the surface presents the form of the letter W, or of 
two crescents, confluent where contiguous. At the same period, the inner lobes 
present distinct broader crescents of exposed dentinal substance. As the attrition 
proceeds, the latter crescents increase in breadth, and also become continuous. 



40 OEEODON. 

Subsequently, small portions of the external faces of the inner lobes, in continuity 
Avith greater portions of the internal faces of the outer lobes, are left upon each 
tooth, in the form of two crescentic islets of enamel, occupying the middle of broad 
spaces of dentine. The portions of the external faces are first obliterated, but they 
are speedily followed by the remaining portions of the other faces ; and the teeth 
then present only broad, quadrate, dentinal surfaces, bordered by enamel, and 
bilobcd internally and externally. (VI. 2.) 

All the premolars have a general resemblance to those of Anoplotliermm, but 
they differ in many details of structure. The fourth premolar is composed of a 
single pair of symmetrical lobes, as are the functional three premolars of all exist- 
ing ordinary ruminants, and the corresponding tooth of the Camel. The lobes of 
the fourth premolar are the equivalents of one of the transverse pairs of the true 
molars, except that they are considerably larger, and that the column at the antero- 
external margin is not as prominent. (11. 1, 3; III. 1, 2.) 

The nnterior three premolars decrease a little in succession forward, and the 
cruwn of each forms an irregular trilateral pyramid with a pointed apex. The 
third premolar is broader posteriorly than anteriorly; and, in transverse section, it 
forms nearly an equilateral triangle. The others are of more uniform breadth 
transversely, and in section have a more elliptical outline. 

In all the premolars, the outer face is cordiform ; and in the last of them, it is 
concave transversely ; in the third it is less so ; and in the remaining two it is 
convex, in consequence of the gradually increasing breadth of the median promi- 
nence common to these and the true molars. 

The inner, side of the crown of the third premolar presents a lobe which is like 
the internal lubes of the true molars; but it is aborted, and it occupies a position 
exactly corresponding with that of the posterior half of the inner face of the 
external lobes of the true molars. In advance of this aborted lobe, the anterior 
half of the inner face of the tooth presents a double enamel fold, inclosing a pair 
of culs-de-sac. 

The inner portions of the two anterior premolars present the same elements of 
structure as the thii'd, but in a more rudimentary condition; in the first premolar, 
the postero-iuternal lobe, as it exists in the two premolars behind it, being almost 
entirely obsolete. 

From mastication, the grinding surface of the fourth j^remolar passes through 
the same phases as the corresponding portion of a true molar. Among our speci- 
mens of the other premolars, there are none which exhibit the course of attrition ; 
but there are several which indicate that, at first, the wearing is greatest at the 
postero-internal side. 

Inferior Molars.— {F\. II. Figs. 1, 3; III. 3-6; IV. 4 ; VI. 4-11.) As in all 
existing ruminants, the lower true molars of Oreodon have two pairs of symmetrical 
lobes ; and the last of the series has an additional lobe. 

In their form they bear a very great resemblance to those of the Deer, but they 
are relatively more expanded in breadth, and the transverse pairs of lobes are less 
oblique relatively to each other. Other and important difl'ei'ences are briefly as 
follows : — 



OREODON. 41 

The inner lobes internally are less prominent in the middle line ; their posterior 
marginal fold is less developed, is shorter, and more divergent; and their external 
face is more convex. (III. 4.) 

The outer lobes are less angular externally, and are more tapering from their base. 

Finally, the tubercle between the bottom of the outer lobes is not conoidal, but 
it appears as a transverse talon with an external angular notch. 

The posterior lobe of the last true molar is relatively larger than in the Deer, 
and is more elliptical in transverse section. (111. 5, 6.) 

In the attrition to which the inferior true molars are subjected in mastication, 
crescentic surfaces of dentinal substance are exposed by the removal of the origi- 
nally acute enamel summits of the lobes. As the wearing progresses, the dentinal 
crescents increase in breadth ; most rapidly upon the outer lobes until the abrasion 
reaches the bottom of the inner faces of these; at which period the outer dentinal 
crescents are considerably below the inner ones, and are twice as broad. At the 
next stage, a small portion of the internal face of the outer lobes, in union with a 
larger portion of the external face of the inner lobes, is left between each trans- 
verse pair of lobes as a crescentic islet of enamel upon a broad surface of dentine. 
The external portion of the islet is- next obliterated, and is soon followed by the 
remainder or internal portion. At a late period, the upper surface of the external 
portions of the basal ridge is worn away by the apices of the outer lobes of the 
superior molars, so as to leave shallow pits in the dentine. (VI. 5, 8.) 

The inferior premolars exhibit more peculiarity in comparison with the true 
molars, than do the anterior three upper premolars. (II. 1, 3 ; III. 3, 4 ; VI. 4, 5, 8, 9.) 

In the Deer, it is easy to trace in the lower premolars, the constituent lobes of 
the true molars. Thus, in the third premolar the anterior pair of lobes are very 
like the corresponding pair in the true molars, but the posterior pair have under- 
gone modification in size, form, and position. In the second premolar, the antero- 
internal lobe of the true molars appears to be represented by the anterior double 
fold, their corresponding outer lobe by the succeeding largest fold, and their poste- 
rior pair of lobes by the two hinder folds. In the first premolar, all of the four 
lobes may be traced as in the second premolar; but all, save the homologue of the 
antero-external lobe, are reduced to their most rudimentary condition, and in some 
individuals are entirely obsolete. 

The plurality of lobes of the true molars is much less readily distinguishable 
in the premolars of Oreodon than in those of the Deer; nevertheless, their gradual 
disappearance may be traced. 

The premolars decrease in size from the last to the first, and each presents an 
antero-posteriorly broad pyramidal crown. The transverse section of the crowns of 
the posterior two at their base is an isosceles triangle with the apex directed for- 
ward ; while the section of the crown of the anterior at the same position is elliptical. 

Externally they are all prominent at the middle and are convex transversely, and 
the posterior half of the surface is directed outward ; while the anterior portion 
presents forward and outward. The first premolar is simply convex externally; the 
second presents a slight fold at the posterior part of the external surface ; and the 
third is depressed posterior to the median prominence of the same surface. Postero- 



42 OREODON. 

internally the last premolar is excavated into a quadrilateral cul-de-sac, of which 
the inner boundary is a pyramidal tubercle, the homologue of the postero-iuternal 
lobe of a true molar. The outer apex of the tooth continues inward upon the sum- 
mit of a pyramidal sub-lobe, apparently homologous with the antero-internal lobe of 
a true molar. In advance of this sub-lobe, there is a broad notch sloping to the 
base of the tooth. 

The second premolar exhibits internally a rudimentary form of the correspond- 
ing portion of the tooth behind. The tubercle has disappeared; and the sub-lobe 
in advance of this has degenerated into an oblique ridge descending obliquely 
backward from the summit of the tooth. The surface postero-internal to this ridge 
is sloping, and receives from it a slight abrupt offset. Anterior to the ridge, the 
internal surface presents a simple, broad, sloping depression. 

The first premolar exhibits internally a simple ridge descending from the summit 
obliquely backward, and dividing the surface into two depressions, of which the 
anterior is the broader. 

In ti'acing upon the premolars, among our specimens, the effects of mastication, 
it is observed that when the enamel is nearly obliterated from the triturating sur- 
faces of the true molars, the bottom of the posterior cul-de-sac in the third premolar 
is left as a small oval islet of enamel upon a broad shoe-formed surface of dentine ; 
while the second premolar is worn so as to present a surface of dentine having the 
form of a Greek s. (VI. 8.) 

As in existing ruminants, the inferior molar teeth of Oreodon are inserted by 
two fangs ijlaced one before the other. The last molar having a fifth lobe, the pos- 
terior fang is proportion ably broad, and is constituted by a confluent pair. 

Canines. — (PL II. Figs. 1, 3; III. 1, 2.) The possession of well developed 
canine teeth in both jaws, is one of the most remarkable characteristics of Oreodon. 
The form of these teeth is peculiar; neither those above nor below grow from per- 
sistent pulps ; and only the crowns are capped with enamel. Those which I have 
concluded to belong to the male of Oreodon, are more robust than those attributed 
to the female. 

The upper canine, commencing at the extremity of its fang above the interval 
of the first two premolars, curves forward, downward, and in a less degree outward. 
In the male, it is directed more externally than in the female. The fang of the 
upper canine renders the face slightly prominent along its course, and is trihedral, 
with rounded margins, and approaches more or less a cylindroid form. In some 
specimens it is flattened, or nearly so, upon the outer side, and exhibits one or two 
slight flutings at the lower part. 

The crown is a trihedral pyramid, with the lateral margins acute, the anterior 
margin subacute, and the sunnnit pointed. Its sides are nearly equal; one being 
directed outwardly, another inwardly and forward, and the third posteriorly. The 
first is nearly plane ; and the second is also nearly plane, and presents a median 
obtuse ridge, which vanishes above in the fang, and below towards the point of the 
crown. The remaining side is visible in only one specimen ; its enamel is Avorn 
off, excepting a small portion at each basal angle; and it is quite plane and smooth, 
and is a little larger thdn the other sides. 



OREODON. 43 

The point and lateral margins of the crown of the upper canine were kept con- 
stantly sharp, by being subjected to attrition only at the posterior part, where it 
came in contact with the corresponding tooth of the lower jaw. 

The inferior canine is straight, and is directed from the end of its fang obliquely 
upward, forward, and outward. 

The fang is variable in its form in different specimens; in one its section is 
transversely compressed and elliptical, in another cyliudroidal, and in a third quad- 
rilateral with rounded margins. 

The crown is a broad, transversely-compressed pyramid, with trenchant margins 
converging to a slightly rounded but sharp summit. It is of about the same length 
as that of the upper canine, but is a little broader. 

The inner face is convex; and the outer ftice is angularly convex, with one por- 
tion directed outwardly, and the other antero-externally. 

The anterior margin is directed inward and forward, and at its outer part, 
wJieu the jaws are closed, comes into contact with the posterior face of the upper 
canine, so as to suffer from attrition most in this position. The margins at the 
bottom of the crown project slightly beyond the outline of the fang. 

The enamel of the canines is a little thicker externally than internally, and is 
slightly corrugated ; and that upon the trenchant margins of the lower ones has a 
slightly crenulated appearance. 

Incisors. — (PL II. Figs. 1, 2.) In only one specimen among the many under 
investigation are the incisors preserved, and in this, their outer face alone is visible, 
the other being enveloped in a matrix, the removal of which would endanger their 
integrity. There are three incisors above, and four below, upon each side of the 
median line. 

Of the superior incisors, the internal is smaller than the outer two, which are 
nearly equal in size. Their outer f\xce is convex, and they are trapezoidal or nearly 
ovoid in outline, with the long diameter about one-fourth greater than the trans- 
verse. The cutting edge and inner margin are convex, and the outer margin has 
a slightly prominent talon. 

Of the inferior incisors, the internal is the smallest; the succeeding two are 
nearly equal in size, and the external is a fifth larger than the others. The outer 
face of the anterior three incisors is convex, and oblong quadrilateral. The cutting 
edge of the first incisor is convex, that of the second slightly so, and that of the 
third straight. The lateral margins have a more prominent talon than those of the 
incisors above, and this is larger externally, and is situated about half-wa}- down the 
crown. The outer face of the external or fourth incisor is also convex, but is more 
trapezoidal than the others. Its cutting edge is convex, and is above the level of 
those of the incisors in advance of it. The lateral margins are oblique and nearly 
straight. 

The presence of eight incisors, in addition to well-developed and undoubted 
canines, in the lower jaw of Oreodon, appears to indicate, in accordance with the 
view of M. Cuvier, that the lateral or fourth incisors of existing ruminants, are true 
physiological incisors ; and not transformed canines, as inferred by Mr. Owen, unless 



44 OEEODON. 

we adopt a hypotliesls wliich supposes the lateral incisors of Oreodon to be trans- 
formed canines, and the functional canines to be the transformed first of the 
normal series of seven molars. The latter view is favored by the absence in 
Oreodon of the first of the normal number of molars, and also by the unusual 
position of the inferior canine tooth. Further, the latter has almost the exact form 
which would be produced by merely prolonging the crown of the first functional 
premolar. On the other hand, in Pukeoiheriiim, the lower and upper canines have 
the same relative position as in Oreodon, and yet the lower jaw has the normal 
number of premolars. 

Temporary Dentition and Order of Succession. — The deciduous dentition of 
Oreodon, so far as can be ascertained from the specimens under investigation, is 
expressed by the following formula : — 

. ? 11 2 2 11 

^. — c. pjn. m. ■ 

? 11^ 2 2 11 

In the order of protrusion of the temporary molars, judging from the relative 
extent of abrasion which these teeth have undergone in the specimens under 
observation, the true molar is first, and then follow the j)remolars in succession 
from behind forward. 

Form of the Temporanj Molars.— {V\. IV. Figs. 4, 5 ; V. 2, 3; VI. 6, 7, 10, 11.) 
The superior temporary true molar has exactly the same form as the permanent 
true molars, but is about one-sixth less in size than the first of these. (V. 2, 3.) 

The crown of the second upper premolar is composed of three lobes like those 
of the true molars : two posterior and transverse, the other antei'ior and opposite 
to them. It resembles very much the crown of the fourth permanent premolar in 
conjunction with that of a small third premolar-. The anterior lobe at its inner side 
is connected with the adjacent side of the postero-internal lobe by means of a 
shallow fold, which forms a cid-de-sac between the two. 

The anterior premolar has nearly the same form as the corresponding permanent 
tooth, but is smaller in size. Its antero-internal cids-de-sac are not as deep as in 
the latter, and the external of these is twice as broad as the other, but is shallower. 

The inferior deciduous true molar, as in all existing ruminants, possesses three 
pairs of symmetrical lobes, which have the same form, and the same relative posi- 
tion with one another as those of the permanent true molars, but which decrease 
in size from behind forward. (IV. 4, 5 ; VI. 6, 7, 10, 11.) 

The two deciduous premolars of the lower jaw closely resemble in form the 
corresponding permanent teeth. 

The normal first superior molar appears to belong to the permanent series, 
succeeds all the temporary molars in the order of protrusion, and has no deciduous 
predecessor. 

The permanent true molars successively protrude and occupy their functional 
position before any of the deciduous molars are shed. The displacement of the 
latter by their permanent successors, appears to begin with the eruption of the 
last of these, which is followed by those in advance. The first permanent 
premolar of the upper jaw appears to have protruded after the deciduous teeth, 



OREODON. 45 

and occupied a position witli them in the functional series, but remains after these 
are shed. 

In comparing Prof Owen's figure of the series of upper molar teeth of IIijopo- 
tamus 'vectianus (in Plate VII. Vol. IV., of the London Quarterly Journal of the 
Geological Society), with that stage of the dentition of Oreodon in which the per- 
manent true molars occupy their functional position in company with the deciduous 
teeth, I cannot avoid a suspicion that what are represented as the third and fourth 
permanent premolars (the latter of which has the exact form of the succeeding 
permanent true molars), are really deciduous teeth, which were to give place to 
more simple, bilobed, anthracotheroid, permanent premolars. The teeth, however, 
represented as of the latter character, to belong to the deciduous series, appear too 
slightly worn in relation to the condition presented by the first permanent true 
molar, although it is not improbable that the permanent true molars might follow 
the eruption of the deciduous teeth so rapidly as to exhibit little difference in the 
relative extent of their abrasion. In the lower jaw of an undoubtedly adult indi- 
vidual of another species, Hijopotamus hoviniis (represented in Fig. 3 of Plate VIII. 
of the same work), it is observable that the anterior two permanent true molars 
are deeply worn, while the two permanent premolars in advance are but slightly 
abraded, which could not be the case under such circumstances as those presented 
by the upper teeth in the figure first referred to. 

Oreodon Culbertsonii. 

(Pl. II. ; III. ; IV. Figs. 1-5 ; V. Figs. 1, 2 ; VI. Figs. 8-11.) 

Merycoidodon Culbertsonii, Leidy: Proc. Acad. Nat. Sci., 1848, iv., 47, pl. figs. 1-5. 

Oreodon prisons, Leidy: Proc. Acad. Nat. Sci., 1851, v., 238. 

Cotylops spcciosa, Leidy : Proc. Acad. Nat. Sci., 1851, v. 239. 

Oreodon Oulbertsonii, Leidy : Owen's Keport of a Geol. Survey of Wise, etc., 548. 

Of this species of Oreodon, I have had the opportunity of examining the fol- 
lowing specimens : — 

1. A very much fractured skull, with the posterior extremity, zygomata, post- 
orbital arches, upper margins of the orbits, upper part and left side of the end of 
the nose, and most of the teeth of the left side broken away. 

On the right side, the entire series of teeth exist in both jaws in a state almost 
as perfect as when the animal was living. (Plate II. Fig. 1.) 

From the collection of Mr. T. A. Culbertson. 

MEASUREMENTS.^ 

Inches. Lines. 
Heigbt of face from iufra-orbitar foramen to tlie end of the angular process of 

the OS frontis ............ 1 '1 

Distance of supra-orbitar foramina from the ossa nasi ..... / 

Height of symphysis of lower jaw ........ 1 8 



' As far as the specimens permit, measurements are given to show the variations which may iu this way 
exist in different individuals. 
7 



46 



OREODON. 



Inches. 


Lines 




11 


4 


3 


4 


4 


3 


4 


3 


8 


1 


10 


2 






9 




11 




7 




3 




li 



Depth below the hinder portion of the lower middle premolar 

Lengtli of entire series of upper teeth . 

Length of entire series of lower teeth . 

Length of series of upper molar teeth . 

Length of series of lower molar teeth . 

Length of series of upper true molar teeth 

Length of series of lower true molar teeth 

Antero-posterior diameter of last upper molar 

Antero-posterior diameter of last lower molar 

Length of crown of the canine teeth 

Extent of hiatus behind the upper canine 

Extent of hiatus between canines and incisors 

2. A very much mutilated skull, with the zygomata, upper superficial portion of 
the face, orbital margins, and rami and greater jjortion of the base of the lower 
jaw broken away. The specimen is very much fissured, apparently from exposure 
to the weather since its exhumation. All the teeth, except the crowns of the 
canines and incisors, remain on both sides. 

The form, proportions, and size of the specimen correspond pretty closely with 
that first indicated. 

From Messrs. Culbertson's collection. 

MEASUREMENTS. 

Length of head from occipital condyles to the anterior incisive alveoli 
Breadth of face at infra-orbitar foramina ..... 

Breadth of face above first premolar ...... 

Breadth of face at roots of incisors just in advance of the upper canines 
Height of symphysis of lower jaw ...... 

Depth of lower jaw below second premolar ..... 

Length of series of upper molars 
Length of series of lower molars 
Length of series of upper true molars 
Length of series of lower true molars 

3. A much broken anterior portion of a skull, agreeing very closely in its form 
and proportions with the corresponding part of the preceding specimens. 

From Capt. Van. Vliet's collection. 



Inches. 


Lines 


7 


5 


1 


Si 


1 


7J 


1 


2i 


1 


7 


1 


i 


3 


5 


3 


3 


1 


9 J 


1 


11 



MEASUREMENTS. 

Breadth of face at infra-orbitar foramina 

Distance from the latter to the frontal angular processes 

Length of series of upper molars .... 

Length of series of lower molars .... 

Length of series of upper true molars 

Length of series of lower true molars 

4. An anterior portion of a skull containing all the true molars and one last pre- 
molar, with fragments of the others. It is accompanied by a portion of lower jaw 
containing the last premolar and the succeeding two true molars. 



Inches. 


Lines 


1 


9 


1 


4J 


3 


5 


3 


4 


1 


9 








OKEODON. 47 

The specimen agrees with the preceding, except that the face is more flat above 
so as to appear of less depth, and in transverse section more square. 
From Messrs. Culbertson's collection. 

MEASUREMENTS. 

Inches. Lines. 

Breadth of face at infra-crbitar foramina . 1 6 

Breadth of face above the fir-st premolar ....... 1 6 

Height from infra-orbitar foramina to angular processes of os frontis . .1 2 J 

Breadth of ossa nasi between the points of the latter processes ... 11 J 

5. A portion of a very much mutilated skull, with attached fragments of both 
sides of the lower jaw widely extended from the upper teeth. Upon one side the 
specimen contains all the upper true, and the lower posterior two true molars, and 
on the other side the upper posterior two and the last lower molar teeth. 

From Messrs. Culbertson's collection. 

MEASUREMENTS. 

Inches. Lines. 
Length of series of upper true molars ....... 1 11 

Antero-posterior diameter of the upper last molar 10 

Antero-posterior diameter of the lower last molar ..... 1 

6. A fragment of the right side of the face of a young animal, containing a 
portion of the first, the entire second, and the inner portion of the third temporary 
molars, and the succeeding two permanent molars. 

It was this specimen to which I applied the name Cotylops speciosa, erroneously 
supposing it to be distinct from Oreodon. 
From Capt. Van Vliet's collection. 

7. Thirteen fragments of upper and lower jaws, all containing from one to 
three true molars, except one, in which are preserved the antei'ior two lower pre- 
molars. They apparently belonged to seven different individuals. 

From the collections of Dr. Owen, Capt. Van Vliet, Dr. Prout, Prof O'Loghland, 
and Messrs. Culbertson. 

8. A portion of the right side of the lower jaw of a young animal, with the 
remains of the anterior two temporary premolars ; the entire temporary true molar, 
considerably worn; and the succeeding two permanent molars. (PI. VI. 10, 11.) 

From the collection of Capt. Van Vliet. 

9. A nearly entire skull, comparatively slightly fractured, and wanting only 
the end of the nose anterior to the canines, the upper of the latter, the incisors, 
zygomata and post-orbital arches, a portion of the parietal crest, and the right angle 
of the lower jaw. • 

Its details of form vary in a very slight degree from those of specimen 1. In 
the latter, it was observed in the table of measurements, a hiatus of one and a 



Inches. 


Lines 


1 


6} 


1 


3 


1 


4 




81 


3 


4} 


3 


4 


1 


10 


2 


i 



48 OREODON. 

half lines in extent existed between the canines and incisors, but in the specimen 
under inspection no hiatus existed in a corresponding position of the lower jaw, 
the lateral incisor having been in contact with the canine. (Plate II. Fig. 2.) 
From the collection of Dr. David Dale Owen. 

MEASUREMENTS. 

Breadth of face at infra-orbitar foramina 

Breadth of face above first premolar 

Distance from infra-orbitar foramina to frontal angular processes 
Breadth of ossa nasi at the points of the latter processes 

Length of series of upper molars 

Length of series of lower molars ....... 

Length of series of upper true molars » . 

Length of series of lower true molars ...... 

10. A skull with the anterior extremity of the nose, the zygomata, and summit of 
inion broken away. The forehead is slightly crushed, but otherwise the specimen 
is comparatively well preserved. It contains all the molar teeth of both sides, the 
left canine, and the fang of the right canine. A small fragment of the right side of 
the lower jaw, containing the true molars, accompanies the former specimen. 

The skull I suspect to have belonged to a male individual of Oreodon Culhert- 
sonii, on account of its generally more robust character than most of the others 
which have been indicated; and specimen 9, particularly, I suppose to have 
belonged to a female. 

Besides the relatively greater degree of robustness of the male skull of Oreodon 
Cidhertsonii, the face is depressed or flattened above, or is not so much arched as 
in the female, and in transverse section it has a more square than conoidal appear- 
ance, as in the latter. The molar teeth, also, are more robust, and the true molars 
possess a well-developed ridge between the bases of the external columns or but- 
tresses, and a feebler ridge exists externally at the base of the premolars. The 
canines are a little more robust, a little longer, and project a trifling degree more 
outwardly. 

In the specimen under immediate inspection, the supra-orbitar foramina are nearer 
the centre of the forehead on each side than in any of the preceding. 

The parietal region on one side of the sagittal suture presents an irregularly 
eroded and areolated vascular appearance, with several slight thin exostoses, indi- 
cating inflammation to have existed during the life of the animal. (Plale III. 
Figs. 1, 2.) 

From the collection of Dr. Owen. 

MEASUREMENTS. 

Breadth of face at infra-orbitar foramina ...... 

Breadth of face above first premolar ....... 

Distance from infra-orbitar foramina to frontal angular processes 
Breadth of ossa nasi at the ends of the latter processes .... 

Length of scries of upper molars ....... 



Inches. 


Lines 


. 1 


1h 


. 1 


7i 


1 


4 




9^ 


. 3 


7 J 



OUKODON. 



49 



Lengtli of series of upper true molars 
Autero-posterior diameter of last upper molar 



Inches. Lines. 

1 Hi 
9 J 



11. The facial portion of a skull, apparently of a male, containing all the 
molars except the crown of the first premolar. In section, it presents the same 
squareness of character as in specimen 10, and also has the same flatness above and 
uniformity of breadth anteriorly. The ossa nasi have been slightly shorter than 
those in specimen 10, and less rounded posteriorly. 

The specimen is remarkable in comparison with that last indicated, because the 
true molars are a little smaller and the premolars a little larger ; but this increase 
of the latter is in breadth, and not antcro-posteriorly, so that it produces no effect 
upon the length of the series. 

The basal ridge of the molars is more feebly developed internally than in 
specimen 10, and externally it is obsolete. 

The hard palate is slightly more arched, and has a little greater breadth than in 
specimen 10. 

From Capt. Van Vliet's collection. 

MEASUREMENTS. 

Breadth of face at infra-orbitar foramina .... 

Breadth of face above first premolar ..... 

Distance from infra-orbitar foramina to frontal angular processes 

Breadth of hard palate posteriorly 

Breadth of hard palate anteriorly 

Extent of hiatus posterior to the upper canine 

Length of series of upper molars 

Length of series of upper true molars . 

Antero-posterior diameter of last upper molar 

12. A fragment of the face and forehead. The former in transverse section is 
nearly square, but is rather more arched above than in specimen 10, and is narrower 
and less deep than usual. 

From Dr. Owen's collection. 



Indies. 


Lines 




7^ 




7i 




2 




5 




4 




2* 


. 3 


5 


. 1 


9 




9 



MEASUREMENTS. 

Breadth of face at infra-orbitar foramina .... 
Breadth of face above first premolar ..... 
Distance from infra-orbitar foramina to frontal angular processes 
Breadth of ossa nasi at the ends of the latter processes . 



Inches. 
1 
1 
1 



Lines. 

i 
11 



13. A portion of the face and forehead of an individual just arriving at adult 
age. Though very imperfect, the specimen is an instructive one, as it exhibits the 
order of succession of the permanent to the temporary molar teeth. 

Upon the right side, the last molar is preserved and fully protruded, and has 
the enamel summits of its anterior lobes slightly worn. The second true molar 
has the dentine exposed upon the summits of the lobes ; most so upon that antero- 



50 OREODON. 

internal, and least so upon that postero-internal. Of the first true molar the inner 
half alone is preserved, and presents the corresj)onding lobes with broad cresceutic 
surfaces of dentine. 

The socket of the fourth premolar had lost its tooth, and is now filled with 
matrix. 

Portions of the crowns of the third and second premolars, yet remaining, indicate 
that these teeth had not been protruded from the gums. 

From this account, it appears that all the permanent true molars are fully pro- 
truded before the temporary molars are shed. 

The two entire teeth above indicated, are in this specimen a trifling degree 
smaller than in specimens 1 and 10, and yet the fragment of skull, though not of a 
fully adult animal, is larger than the corresponding portion of any of the preceding 
specimens described. In the upper view, it appears as if it had belonged to a 
distinct species from Oreodon Culhertscmii, and had it been the only specimen in 
the collection besides the first indicated in the list, I would have so considered it 
without hesitation, but, from the many variations presented in numerous individual 
cases, I am inclined to think it is only a variety. 

The forehead is unusually long and broad ; being about three-fourths of an inch 
greater in the former direction than in the largest specimen previously indicated. 
The supra-orbitar foramina are removed to double their usual distance from the 
fronto-nasal suture, or rather they appear to occupy the ordinary position, while 
the portion of the os frontis in advance of them is unusually prolonged. The 
lachrymal depression, also, is more shallow than usual, apparently by the spread- 
ing or expansion of the lachrymal bone; for the outer face of this is several lines 
higher and broader than in the preceding specimens. 

From the collection of Dr. Owen. 

MEASUREMENTS. 

Inches. Lines. 

Distance of infra-orbitar foramina from frontal angular processes ... 1 6 

Distance of supra-orbitar foramina from fronto-nasal suture .... 1 2 

Length of series of upper true molars 1 9 

Antero-posterior diameter of last molar ° 

14. A fragment of a face of a young animal, containing on both sides portions 
of the temporary molars ; the succeeding two permanent true molars ; and, con- 
cealed within the jaw, the last molar. 

From the collection of Dr. Owen. 

15. The greater portion of a face and lower jaw, containing all the molars 
except one of both sides. It presents nothing peculiar, except a slight variation 
in details of size. 

From the collection of Dr. Owen. 



OREODON. 



51 



MEASUREMENTS. 

Inches. Lines. 

Breadth of face at infra-orbitar foramina . . . . " . . .1 8 

Distance from infra-orbitar foramina to frontal angular processes ... 1 4 

Length of series of upper molars 3 1 

Length of series of lower molars . . . . . . , .3 

Length of series of upper true molars 1 8 

Length of series of lower true molars 1 10 

16. The skull of a young animal, accompanied by the greater portion of the left 
side of the lower jaw. The end of the nose and superficial portioh of the right 
side of the face are broken away. The upper jaw, on the right side, contains all the 
molars perfect; consisting of the first permanent premolar and the succeeding three 
temporary and two true molars protruded, and the last true molar just on the 
point of protrusion. The portion of lower jaw also contains all the molars nearly 
perfect; consisting of three temporary molars and three permanent true molars, the 
last of which is only partially protruded. 

Independently of the specimen not being adult, it evidently indicates a smaller 
individual of Oreodon Cidhertsonii than any of the others previously designated. 
(Plate V. Figs. 1, 2.) 

From the collection of Dr. Owen. 



MEASUREMENTS. 

Length from occipital condyle to canine alveolus . 
Length of series of upper molars . . . 

Length of series of lower molars 
Length of series of upper permanent true molars 
Length of series of lower permanent true molars 
Antero-posterior diameter of last upper molar 
Antero-posterior diameter of last lower molar 

17. Fragment of the left side of the lower jaw of an old individual, containing 
the true molars and the two premolars in advance, with the characteristic enamelled 
triturating surfaces nearly obliterated. (Plate VI. Figs. 8, 9.) 

From the collection of Dr. Owen. 



;lies. 


Lines 


6 




3 


1 


3 




1 


8 


1 


10 




7f 




9 



MEASUREMENTS. 



Length of series of true molars 
Antero-posterior diameter of last molar 



Inches. Lines. 
1 9 

10 



18. Seven fragments of upper and lower jaws, containing true molars, appa- 
rently from six different individuals. 
From the collection of Dr. Owen. 



19. A skidl, without the lower jaw, and with the end of the nose and posterior 
part of the cranium broken away. It is particularly valuable from its preserving 
the post-orbital arch entire on both sides. The teeth are all broken. (Plate IV. 
Fig. 3.) 

From the collection of Dr. Hiram A. Prout, of St. Louis. 



52 



OREODON. 



20. Fragments of the upper and lower jaw, the former containmg the last two 
molars, the latter the last three molars. Upon these was originally established the 
Merycoidodon Cidhertsonii, in the Proceedings of the Academy of Natural Sciences 
(vol. iv. p. 47. Plate: Figs. 1-5). 

The specimens were collected by Mr. Alexander Culbertson, and presented to 
the Academy of Natural Sciences by his father Mr. Joseph Culbertson. 



Average ifeasuremenfs of Specimens of Oreodon Culbertsonii ; hut principallij taken 
froiii the female head represented in Plates 11. and IV. Figs. 1, 2. 



Length of skull from occipital condyles to incisive alveoli iu the female 

Length of skull from occipital condyles to incisive alveoli in the male 

Length of fiiee from antero-orbital margin to incisive alveoli 

Length from post-glenoid tubercle to incisive alveoli 

Length from hinder part of last molar to incisive alveoli 

Length from iuion to coronal suture 

Length from coronal suture to end of nose . 

Length of OS frontis at middle .... 

Greatest breadth of skull at zygomata . 

Greatest breadth at inter-temporal region, near middle 

Least breadth at coronal suture .... 

Breadth at middle of post-orbital arches 

Breadth of face above last molar 

Breadth of face above first premolar 

Breadth of face at infra-orbitar foramina 

Breadth between ends of frontal angular processes 

Breadth of each nasal bone .... 

Vertical diameter of the orbit .... 

Transverse diameter of the orbit 

Greatest length of lower jaw .... 

Height of lower jaw at coronoid process 

Height of lower jaw at condyle .... 

Height of lower jaw at last molar 

Height of lower jaw at second premolar 

Length of series of upper molars 

Length of series of lower molars 

Length of series of upper true molars 

Length of series of lower true molars 

Antero-posterior diameter of last upper molar 

Antero-posterior diameter of last lower molar 

Antero-posterior diameter of penultimate lower molar 

Antero-posterior diameter of upper premolars 

Antero-posterior diameter of lower premolars 

Length of crown of upper canine 

Length of crown of lower canine 

Breadth of lateral series of upper incisors 

Breadth of lateral scries of lower incisors 

Length of crown of upper internal incisor 

Length of crown of upper lateral incisor 

Length of crown of lower internal incisor 

Length of crown of lower lateral incisor 



Inches. Lines. 

7 4 



7 
3 
6 
4 
2 
4 
1 
4 
1 
1 
3 
2 

1 
1 



1 
1 
6 
3 
2 
1 
1 
3 
3 
1 



9 

6 

6 

3 
10 

8 
10 

2 

7 
3 
3 
9 
4 
7 
9 
5 
3 
1 
2 
3 
9 
7 
1. 
4 
3 
10 



9 
11 

"7 
5 

5J 
male 9 lines; female 7 

7i 

9 

3* 

4} 

3i- 

5 



OREODON. 



53 



The species is respectfully dedicated to the Messrs. Culbertson, through whose 
aid the first specimens were obtained upon which the genus was established. 

Oreodon gracilis, Leidy. 

{Ph. V. Figs. 3, 4; VI. Figs. 1-7.) 
Oreodon c/racilis, Leid^': Proc. Acad. Nat. Sci., 1850, v., 239; Owen's Rep. ofaOeol. Surv. of Wise, etc., 550. 
Merijcoidodoii gracilis, Leidy ; Owen's Rep., 550. 

This species was first characterized in a verbal communication to the Academy 
of Natural Sciences in August, 1851, from several fragments of an upper and a 
lower jaw containing the true molars and one premolar. ( 

The head is about two-thirds the size of that of Oreodon. Culherisonii. 

The specimens, which I have had the opportunity of examining, are as follows : — 

1. Lower and upper jaws, occiput, and os frontis of an old individual. The 
rami of the lower jaw are broken awa}', but on the left side it contains all the true 
molars, the third premolar, and the fangs of those in advance. The right side of 
the upper jaw contains the true molars, the fourth premolar, and the roots of those 
anterior. (Plate VI. Fig. 4, the lower jaw; Fig. 5.) 

From the collection of Captain Van Vliet. 



MEASUREMENTS. 

Length of series of upper molars .... 

Length of series of lower molars .... 

Length of series of upper true molars 

Length of series of lower true molars 

Distance between ends of frontal angular processes 

Distance between supra-orbitar foramina 

2. The skull of an adult, with the end of the nose, base of the cranium, and 
zygomata broken away. It contains upon the right side the true molars and the 
fourth premolai", and on the left, fragments of all the molars. Accompanying it is 
a portion of the lower jaw, containing the true molars. (Plate VI. Figs. 1-3.) 

From the collection of Drs. Owen and Evans. 



Inches. 


Lines 


2 


2 


2 


2 


1 


2i 


1 


4 




41 




5i 



MEASUREMENTS. 

Breadth of cranium above roots of zygomata .... 
Breadth of cranium at most prominent part of the temporal fossae 
Distance from bifurcation of sagittal crest to ossa nasi 
Distance between supra-orbitar foramina ..... 
Length of series of upper true molars ..... 

Length of series of lower true molars ..... 

3. A fiicial fragment containing on the left side the last two molars, the fangs of 
all those in advance, and that of the canine. It is particularly valuable from the 
left orbit being preserved entire. 

8 



Inches. 


Lines 


1 


6 


1 


4 


1 


6J 




3* 


1 


3 


1 


4 



54 



OREODON. 



The specimen corresponds in its proportions and details with specimen 2. (Plate 
VI. upper part of Fig. 4.) 

From the collection of Dr. Owen. 



MEASUREMENTS. 



Length of series of upper molars 
Breadth of face at infra-orbitar foramina 
Distance between supra-orbitar foramina 
Distance between frontal angular processes 



Inches, 
o 



Lines. 

1 
11* 

4 

8i 



4. The skull accompanied by the right side of the lower jaw of a young animal. 
The former has the posterior and superior portions of the cranium and the nose 
broken away; the latter the ramus and symphysis. 

The upper jaw contains on the left side the molar series nearly complete, con- 
sisting of the first permanent premolar, the temporary molars, and the succeeding 
two permanent true molars which are fully protruded. 

The portion of lower jaw contains two temporary molars, and the succeeding 
two permanent molars. 

The forehead of this specimen is remarkable for its flatness ; being much more 
arched in the adult. (Plate V. Figs. 3, 4 ; VI. Figs. 6, 7.) 

From the collection of Dr. Owen. 



Average Measurements of Specimens of Oreodon gracilis. 



Estimated length from summit of inion to incisive alveoli 

Breadth below the orbit at the maxillo- malar suture 

Breadth of cranium at most prominent portion of temporal fossae 

Breadth of cranium at narrowest portion .... 

Estimated length of sagittal crest ..... 

Length of forehead in median line ..... 

Breadth of forehead at middle of post-orbital arches 

Breadth of face from above the lachrymal tubercle 

Breadth of face at infra-orbitar foramina .... 

Breadth of face between ends of frontal angular processes 

Height from middle palate suture to fronto-nasal 

Height from middle palate suture on a line with the first premolar 

Diameter of the orbit .... 

Breadth of palate between fourth premolars 

Depth of lower jaw at last molar 

Depth of lower jaw at third premolar 

Length of series of upper molars 

Length of series of lower molars 

Length of series of upper true molars 

Length of series of lower true molars 

Antero-posterior diameter of upper middle true molar 

Antero-posterior diameter of upper fourth premolar 

Antero-posterior diameter of last lower molar 

Antero-posterior diameter of second lower true molar 

Antero-posterior diameter of third lower premolar 



Inches. 


Line 


4 


8 


o 


5 


1 


4J 




10 J 


1 


10 


1 


7 


2 


2 


1 


7 


1 






8J 


1 


3J 


1 


h 




9 




8J 


1 






8 


2 


1 


2 


U 


1 


2J 


1 


4 




5 




3 




7* 




5i 




4 



OREODON. 55 



Comparison helween Oreodun Culbertsonii and Oreodon gracilis. 

Besides the great disproportion in size between Oreodon Cidhertsouii and Oreodon 
gracilis, (the latter being nearly one-third less than the former,) there are other 
differences which, though slight, are important. 

In Oreodon Cidbertsonii, the sagittal crest rises from the sides of the temporal 
fossa3 in a gradual pyramidal manner ; but in Oreodon <jracHis, the intertemporal 
region at its upper part is more arched, and the sagittal crest rises from it in the 
form of a thick, abrupt, rugged, linear ridge. 

In the latter species the lachrymal depressions are relatively less deep, and the 
entrance of the orbits more nearly circular. 

The posterior convergent extremities of the ossa nasi terminate more abruptly 
in Oreodo7i gracilis; or in this they are convex and in Oreodon Calhertsonii are 
angular. 

The ossa tympanica are relatively much more inflated in Oreodon gracilis; and 
the prominent ridge continuous from them to the auditory process in Oreodon 
Culhertsonii, is but feebly developed in the former species. 



• Oreodon luajor, Leidy. 

(Pl. IV., Fig. 6.) 
Syn. MerycoidodoH major. 

A third species of Oreodon with some hesitation is proposed upon a fragment of 
the right side of the upper jaw, containing the true molars, from the collection of 
Dr. Owen. 

The specimen belonged to a middle-aged individual, as indicated by the tritura- 
tion to which the teeth have been subjected in mastication; the characteristic 
enamelled grinding surface of the first true molar being quite obliterated. 

The teeth correspond closely in form with those of Oreodon Culhertsonii, but 
they are much larger than any of the specimens which have been attributed to the 
latter. 

It is not improbable, that upon further investigation, the specimen may prove 
to belong merely to a large variety of Oreodon Cidhertsonii, for the difference in 
size of the teeth from those indicated in the specimen 10, of the latter species, is 
not as great as that existing between the teeth of this and those of specimen 16. 

MEASUREMENTS. 

Inches. Lines. 

Length of series of upper true molars ....... 2 04 

Antero-posterior diameter of the last molar ....... 1 

Breadth anteriorly ........... H 



56 EUCROTAPHUS. 



EUCROTAPHUS, Leidy. 
Eiicrotapliiis Jnck!!ioni, Leidy. 

(Plate VII. Figs. 4-0.) 
Eucrotaplms Jacksoni, Leidy: Proc. Acad. Nat. Sci., 1850, v. 92. 

Eucrofnplitis auritiis, Leidy. 
(Plate VII. Figs. 1-3.) 
Eucroiaplius auritus, Leidy ;• Owen's Kep. of a Geol. Surv. of Wise., etc., 563. 

The genus Eucrotaphus was orisinally proposed in the Proceedings of tlie 
Academy of Natural Sciences of Philadelphia, upon a cranial fragment presented to 
the Society by Mr. Alexander Culbertson through his father, Mr. JosejA Culbertson. 

The specimen is remarkable for the great relative size of the pars squamosa of 
the temporal bone; being hardly equalled in this respect by that of the Camel or of 
Oreodon. 

The family to -which Eucrotaphus belongs has not yet been ascertained with cer- 
tainty, though from the form and proportions of the cranium being so very much 
like those of Oreodon, I suspect it to have appertained to the ruminantia. 

Coincidentally, Dr. Owen's collection contains the portion of a ctanium corre- 
sponding to that just indicated; but it belongs to a different and rather larger 
species. 

Besides the foregoing, no specimens have been discovered, which can be ascer- 
tained to belong to Eucrotaphm. From the similarity in construction of the 
cranium proper of the latter and of Oreodon, and from the decided ruminant cha- 
racters of the sjDecimens upon which Agriochoerus has been proposed, with the 
relations of size which these bear to those of 'Eucrotaphus, I suspect the latter two 
are in realitj- the same genus. 

To the smaller species of Eucrotaphus, the head of which was about the size of that 
of Oreodon CulhertsonU, the name Eucrotaphus Jaclsorii-v/ns given in honor of my 
much esteemed and distinguished friend Dr. Samuel Jackson, Professor of the In- 
stitutes of Medicine in the University of Pennsylvania. 

For the second species the name Eucrotaphus auritus is proposed, from the rela- 
tively larger size of the auditory bulla3. 

It is unnecessaiy to describe in detail the specimens upon whicli the two species 
are founded, for they agree so closely with the corresponding portion of the 
skull of Oreodon, that it is sufficient to point out the peculiarities of structure 
which distinguish them from the latter and from each other. 

The lateral and upper views of the cranium proper of E'U£7viaphus (PL VII. 
Figs. 1, 2, 4, 5,) are identical with those of Oreodon, except, perhaps, the pars 
squamosa is a trifling degree larger in the former, and the parietalia are rather 
more depressed in advance and upon the course of the squamous suture. 

The outline of the base view (Figs. 3, G), and the position of the foramina are 
also the same as in Oreodon; but in Eucrotaplius, the glenoid articulation is rather 



ARCHAEOTHEKIUM. 57 

deeper; the post-glenoid tubercle is shorter and relatively very much more robust; 
and the os tympanica, instead of being slightly swollen at the inner termination of 
the vaginal crest of the auditor}' process, as in the former, is developed into a bulla 
relatively as large as in the Californian Deer. 

In Eucrotaphus Jacksoni (Fig. 6), the auditory bulla forms a large, simple mam- 
millary eminence, which abuts against the sphenoid bone anteriorly and the para- 
mastoid process posteriorly, and rests with its base internally upon the margin of 
the basilar process and the conjunction of this with the sphenoidal body, and is 
outwardly continuous with a ridge the homologue of the vaginal process. 

In Eucrotaphus anritus (Fig. 3), the auditory bulla has the same connections as 
in the former, but in addition rests against the post-glenoid tubercle; and it is rela- 
tively slightly larger, and laterally compressed. 



Fam. 2. — Paridigitata Ordinaria. 

Gen. ARCHAEOTHERlCiW, Leidy: {Entdodon? Aymard.) 

ArchaeoiJierium is a remarlcal^le genus of suilline ungulata combining apparent 
ruminant and carnivorous characteristics. In the form of its superior molar teeth it 
exhibits an affinity to the extinct Clioeropotamibs, Cuvier, and in a less degree to 
the Ilijracotherium, Owen; but, judging from a sketch in Gervais's Zoologie et Pale- 
ontologie Frangaises,^ of the upper molars of EnteJodon, Aymard, it approaches 
this much more nearly than either the former. Indeed, the posterior five 
superior molars of Eiitelodon and Archaeotheriiim are so alike in relative position, 
proportion, and form, that I consider it doubtful whether the latter is distinct from 
the former; but not having an opportunity of examining the original descriptions 
and figures of Aymard," nor of extending the necessary comparisons, I have pi'o- 
visionally retained the generic name originally proposed. 



Archacotlieriiiiu Mortoni, Leioy. 

(Plate VIII ; IX ; X. Figs. 1-7.) 

Archaeotheriiim Mortoni, Leldy : Proo. Acad. Nat. Sci., 1850, v. 92; Owen's Rep. of a Geol. Surv. of Wise, 5.58. 
Archaeolherium [Enlelodon?) Mortoni, Leidy: Owen's Rep. etc., refer, to Table X. 

The species Arcliaeotherium Mortoni was established in the Px'oceedings of the 
Academy of Natural Sciences (Vol. V. p. 92, for 1850), upon a fragment of a face 
containing the third and fourtli premoKars of the left side, presented to the Academy 
by Mr. Alexander Culbertson. 

Later, I have been enabled very greatly to extend our knowledge of this animal 
by the investigation of several interesting specimens in the collection of Dr. Owen. 

One of these is a portion of the face very much mutilated, of an adult individual. 



' P. 102, p. 2, 26, fig. 12. 

^ Mem. Soc. Agric. Sci., etc., du Puy, t. xii. p. 240; 1848. Gervais. 



58 ARCHAEOTHEKIUM. 

containing, on both sides the anterior two true molars, and the fangs of the last 
molar and of the last premolar. The other specimen, much the most important, 
consists of the greater portion of the skull of a young animal, in which the ante- 
rior two permanent true molars had protruded, but all the other permanent molars 
were yet concealed within the jaw. It is broken into two pieces, and is accompa- 
nied by fragments of both sides of the lower jaw. The upper part of the face, left 
orbit, and left zygoma ai'e broken away, but upon the right side the latter two are 
almost perfect. The upper jaw, in its present condition, contains upon the left side 
the posterior five permanent molars (those concealed within the jaw having been 
artificially exposed), and upon the right side, the permanent true molars and the 
posterior two temporary molars. The fragments of the lower jaw consist of one 
of the left side containing the posterior five molars, of which the first and last had 
not yet protruded; and two of the right side, of Avhich one is the angular portion, 
and the other contains the last temporary molar, the permanent last premolar and 
the first and last permanent true molars. 

Description of the SlmU. — The form of the head of Arcliaeoflierium Mortoni is so 
peculiar that I know of none among existing ungulata with which to compare it. 
In viewing it from above, it resembles more in general configuration that of the 
Lion or other species of Felis, than it does that of any of its own tribe now in 
existence. From the head of the Lion, however, it differs in numerous important 
points, among the most striking of which, are, the uniform height forward of the 
sagittal crest, the recession of the temporal fossae, the verticality of the zygomatic 
root, the existence of a post-orbital arch as strong as that of the Camel, the ver- 
ticality of the orbital entrance, the relatively great size and depressed character of 
the forehead, the extent of the lachrymal bone, the more prolonged and demi- 
cylindroidal form of the face, the advanced position of the infra-orbital foramen, etc. 

Lateral'View. — (PI. IX., Fig. 1.) In the side view of the head, the upper outline 
descends slightly from the inion, then rises towards the forehead, and again descends 
along the face as in the Lion, but relatively not to the same extent. The outline 
of the inion appears more oblique than in the Peccary, and is intruded upon by 
the occipital condyles and a vertical convex prominence above them. 

The temporal fossa is quite transverse in its direction in comparison with that of 
the Hog and Peccary, and, as in these, its position is more posterior than in the 
Lion ; but it is relatively longer and less deep than in the former animals, and is 
as much more capacious than these, as is that of the latter animal. Its increased 
capacity is not only produced by extension upward upon a strongly developed 
parietal crest, but also, as in the Choeropotamus and Lion, by the greater extension 
outwardly of the zygoma than in the Hog or Peccary. 

The root of the zygomatic process in association with the mastoid and paramastoid 
processes forms a remarkably strong scroll-like apophysis, which protrudes directly 
outward from the lateral margin of the inion, and expands like the mouth of a 
trumpet, is open below ; and it leads to the meatus auditorius. Its anterior surface is 
an almost vertical convexity, nearly two inches in depth, and contributes very 
greatly to the extent of attachment of the powerful temporal muscle. Externally, 
the zygomatic process becomes abruptly narrowed to less than half the depth of its 



ARCriAEOTHEKIUM. 59 

root, and from this position it turns directly forward and terminates by resting 
upon a long rectangular notch of the malar bone. 

The posterior half of the outer surface of the zygoma forms a nearly vertical 
plane; but anteriorly, where formed by the malar bone, it is remarkable for its 
extraordinary depth ; being over two inches, and is vertically plane above, but 
slightly bent outwardly below. 

In the specimen, the sagittal crest is broken at the inion and along its free mar- 
gin, but it is yet sufficiently entire to exhibit the remarkable uniformity of its . 
height in comparison with that of the Camel and Lion. Posteriorly, as in the 
two latter, it has the appearance of having contributed to the formation of a strong 
process overhanging the inion, but it is not as concave laterally as iu either of 
these animals. 

The margin of the temporal fossa bordering upon the inion is acute, but forms 
no trace of a projecting crest. 

The post-orbital process of the os frontis is as thick and strong as in the Camel; 
and, as in this, has neai-ly the same direction outward and backward, and it joins 
an equally short and strong process of the os malte. 

The temporal surface along the sagittal crest is concave, but below the base of - 
this is uniformly convex in the vertical direction. 

The orbit is relatively larger than in the Hog or Peccary, and is broader below ; 
is vertical and ovoidal at its entrance, and is directed outward and forward at an 
angle of about 45°. Its superior margin is prominent and obtuse, and the lachry- 
mal border forms a simple, compressed mammillary eminence, bounded above and 
below by a rounded notch. Just internal to the lower notch is a single lachrymal 
foramen. Below the orbit the malar bone is remarkably shallow, and its surface, 
from the infra-orbital margin, slopes outward, downward, and backward. . 

The post-orbital ai'ch is even relatively stronger than in the Camel, and has 
about the same form. The possession of this arch by Archaeotherium is a remarka- 
ble peculiarity, as it does not exist in the closely allied Clioeropotamus, nor in any 
of the recent suilline genera, except as an inconstant characteristic in the Hippo- 
potamus. 

The side of the face is vertically convex, and is directed forward in a straight 
line from the position of the termination of the malar bone. 

The outer face of the lachrymal bone is slightly bent and nearly plane and ver- 
tical. The infra-orbitar foramen is vertically oval, and is situated above the posi- 
tion of the penultimate premolar, and nearly three inches in advance of the orbit. 

Superior View. — (PI. IX. Fig. 2.) In the upper view of the head of ArcJiaeo- 
iheri'um, the cylindrical form of the interparietal region, bounded above by the 
high sagittal crest, is a striking pecuiiarity of the genus. 

Between the zygomata the breadth of the head is relatively greater than in feline 
animals. 

The space inclosed by the zygomatic arches is as capacious as in the Lion, but 
is relatively a little longer and not quite so broad, and is oval in form. 

The forehead and prognathous face much resemble those of the Hyracotlieriurn. 



60 ARCHAEOTHERIUM. 

The former is relatively broad compared with that of the Hog and Peccary, and in 
this character and in its form is more like that of the Camel. 

The sagittal crest at its bifurcation is, to an extraordinary degree, strong and 
prominent, and the fronto-temporal ridges leading from them are at first elevated 
and acute, but afterwards decline and become irregular in their course outwardly. 

The forehead presents a rugged appearance; is prominently convex on each side 
above the orbits, and is deeply depressed in the middle. In the greater part of one 
side remaining in the specimen, over the orbit, are two small vasculo-neural fora- 
mina; and near the middle line and the fronto-nasal suture, is a fron to-orbital 
foramen, which is relatively very small to that of the Hog or Peccary. The face 
has the form of a demi-cylinder very slightly convergent forward. Its upper part 
in the latter direction forms a very slightly concave slope similar to that existing 
in the same position in the Dicotijles labiatus. 

Posterior View. — (PI. X., Fig. 0.) The inion forms a broad triangle, from the 
middle of the base of which the occipital condyles project downward and backward, 
and these have very nearly the same form and relation to each other as in the Hog. 

Above the condyles the occiput forms two vertical convex prominences separated 
by a concavit}^ which extends to the summit of the inion, as in the Hog and Pec- 
cary, but is deeper than in these. Laterally, the inion is depressed into a deep pit, 
at the bottom of which is a large foramen communicating with the interior of the 
cranium, as in the Camel. 

Inferior View. — (PI. VIII. , Fig. 1.) The base view of the skull bears consider- 
able resemblance in its form to that of Choeropotamus ; but posteriorly it is relatively 
broader, from the greater degree of extension outwardly of the zygomata. 

The basihar process is demi-cylindroidal, convergent anteriorly, and terminates in 
two latei^al abutments, which rest against a corresponding pair extending as lateral 
ridges from the post-sphenoidal body. 

The post-sphenoidal body at its middle forms a concave gutter, and anteriorly 
terminates at the orifice of a very large az^'gous canal, which also exists in the 
Plog, but in a relatively feebly developed condition. 

The anterior condyloid foramen occupies a position at the bottom of the concave 
lateral portion of the basilar process, a few lines in advance of the condyle. 

In front of the latter foramen is a large, irregularly crescentic foramen lacerum, 
which suiTounds the inner side of the auditory bulla. 

The foramen ovale is situated in front and at the extreme bottom of the zygo- 
matic root. The foramen spheno-orbitale is placed about three-fourths of an inch 
in advance of the ovale, is circular, and is bounded externally by a prominent 
acute ridge, which curves upward and forward, and constitutes the antero-inferior 
limit of the temporal fossa. 

The optic foramen is relatively about as large as that in the Hog, and is situated 
about three lines anterior to the one last described. 

The homologues of the paramastoid processes or the inferior angles of the occiput 
are thick and strong, and are prolonged in a curvilinear manner outward and 
downw^ard. In the specimen they are broken at their extremity, and they are 
associated with the mastoid processes, considerably external to the position of the 



AECHAEOTHEEIUM. 61 

occipital condyles, and constitute the posterior part of the infundibular expansion 
of the root of the zygomatic process. 

The auditory bullae, broken in the specimen, appear to have been broad and 
convex, but compared to those in recent suilline animals were feebly developed. A 
strong conoidal process projected from them anteriorly downward and forward, 
bounding the passage of the Eustachian tube externally, and the foramen caroticum 
internally. Externally, the auditory biftlas are prolonged into a broad and strong 
auditory process. 

The external auditory meatus is circular, is relatively considerably larger than 
in the Hog, and is remarkable for the large infundibular expansion which leads to 
its entrance. 

The inferior border of the root of the z3^gomatic process is thick and convex, 
and is prolonged outward and downward to the glenoid articulation. 

The latter in position and form resembles that of the Peccary ; but it is relatively 
broader and more shallow, or its anterior and posterior tubercles are shorter. 

From the glenoid articulation, t^ie zygoma converges to the face and expands 
outward and downward; and where constituted by the antero-inferior margin of 
the malar bone, it forms a prominent acute edge. 

The posterior palatine notch, as in the Tapir, RJiinoceros, and extinct Choeropo- 
tamus, extends to some part of the space intervening to the penultimate molar 
teeth. It is about three-fourths of an inch wide at its commencement, and has 
nearly parallel sides and a concave bottom. 

The hard palate is concave, and parallel at its sides, and is not roughened as far 
as preserved in the specimen. 

The palate plates of the palate bones are short, as in the Hog ; and the posterior 
palatine foramina are situated in the transverse palatal suture. 

Form, Relations, and Connections of ihe Bones of the Skull. — The parietalia are 
fused at the sagittal crest into a single symmetrical bone, which descends on each. 
side in advance of the pars squamosa, to the bottom of the temporal fossa to join 
the sphenoid bone, and anteriorly is notched for the adaptation of the os frontis. 

The pars squamosa of the temporal bone appears to be almost entirely extended 
outwardly to form the deep anterior face of the root of the zygomatic process ; and 
its suture descends so rapidly that its most anterior part is only a little over an 
inch from the position of the meatus auditorius. 

The OS frontis, even in the young animal, is single, and it contributes to nearly 
one-third of the extent of the temporal surface. Anteriorly, it terminates in an- 
gular processes, which extend in advance of the ossa lachrymalia, and for more 
than two inches along the sides of the ossa nasi. 

The bottom of the fronto-nasal suture is neai'ly on a line with the anterior mar- 
gin of the orbits, from which position the ossa nasi gradually widen to the points 
of the angular processes of the os frontis, and then, in the specimen, in a more 
gradual manner decrease in width to their broken extremities. 

• The facial surface of the lachrymal bone forms an oblong square measuring nearly 
two inches antero-posteriorl3^ 

The maxillo-malar suture descends in the same obli(|ue line, as that anterior to 
9 



g2 ARCHAEOTHERIUM. 

the lacliryinal boue, to about the middle of the position of the penultimate molar 
tooth. 

Inferior Maxilla. — Of the lower jaw we have the opportunity of examining only 
several small fragments, but fortunately these ai^e important ones, as from the form 
of the superior molar teeth resembling very closely those of G/ioeropotamus, we 
might expect to find a lower jaw constructed like that of this animal, which is far 
from being the case. One of the fragments consists of the posterior extremity of 
the right side, externally attached to a mass of matrix. (X. 7.) The coronoid process 
and condyle are broken, but they appear to have preserved their relative proportion 
and position to one another, which are as in modern suilline animals. The tecli- 
nical angle, which is preserved entire, is not prolonged into a hook as in Ghoeropo- 
tamus, nor is it i-ounded as in the Hog and Peccary, but is almost rectangular, and 
lengthened slightly backward and downward, as in the Deer; and it is thick and 
convex at the apex. The ascending ramus is broad, and, as in the Hog, is apparently 
not depressed to any extent in advance of the position of the condyle. The pos- 
terior border of the jaw is vertically concave; *nd, indeed, excepting the condyle 
and coronoid process, the posterior part of the bone partakes of the form of that of 
the Hog and Deer. 

The other fragments are portions of the lower jaw of both sides containing molar 
teeth ; and are two inches in depth below the position of the first true molar. That 
of the right side is an exceedingly interesting and important piece (VIII. 2), for, as in 
Anthracothcrium, it has a short obtuse process projecting from the base of the bone. 
The direction of the process is outward and downward, and it is situated below the 
position anteriorly of the last permanent premolar. From the outward curve of 
the process the jaw above and on a line with it is concave. 

Dentition. — Of the permanent dentition of ArcJiaeoiherium we are acquainted 
only with the posterior five upper molars, and the posterior four below. These are 
constructed upon an undoubted suilline type, but approach none of the recent forms 
so much as they do those of Hi/racotherium, or more those of Choeropotamus, and 
most, if they are not identical with, those of EnteJodon. 

In the specimens, the molar teeth above mentioned form a close row in both 
jaws, and their relation to one another is the same as in the Hog, Peccary, or 
Hippopotamus. 

Superior Molars. — (VIII. 2; IX. 1, 3-5; X. 1.) The upper true molars are con- 
structed after the same type as those of Choeropotamus and Ilijracotlierium, but differ 
principally in the less extent of development of the basal ridge. 

The crowns of the anterior pair of true molars are quadrate with convex sides, 
and internally as in Entelodon magnum have no basal ridge like that existing in the 
other two genera mentioned. The grinding surfiice of these teeth presents two 
transverse rows, each of three conical lobes, of which those external and that 
antero-internal are the larger, and are nearly equal in size; and the remainder are 
subequal. 

The enamelled sides of the lobes are corrugated and their apices are excavated, 
though feebly, compared with what they are in Ilijracollicrium and Clioeropotantus. 



ARCHAEOTHERIUM. C3 

Anteriorly, the crowns are embraced by a strong and deep basal cingulum or 
ridge, relatively more robust than in any of the allied genera. 

In the first true molar a strong basal ridge jDasses in a festooned manner from the 
apex of the postero-internal lobe posteriorly to the base of the corresponding ex- 
ternal lobe, and from this externally to the base of that in advance, but does not 
embrace it as in Entelodon magnum. 

In the second true molar, as in the corresponding tooth of Entelodon magnum, 
the apex of the postero-internal lobe is continuous with a thick basal ridge ascend- 
ing posteriorly from the base of the postero-external lobe; but no ridge exists ex- 
ternally upon the tooth as in the latter animal. 

The last of the true molar series has a quadrilateral oval crown, presenting as in 
the teeth described, an anterior row of lobes, bounded at base anteriorly by a similar 
but shorter and more tuberculated basal ridge. The posterior third of the triturating 
surface is composed of an assemblage of four low tubercles, which correspond to 
the posterior lobes and basal ridge of the two molars in advance. 

The posterior two premolars are not at all like those of Hyracotherium, but are 
constructed upon the same pattern as those of C'hoerojjotamus, and are very much 
like those of Entelodon magnum. 

As in the lattei", the last premolar has a quadrilateral crown with the inner side 
shortest and that anterior oblique. It is composed of a transverse pair of conical 
lobes, of which the internal is the smaller, and both are very much larger than the 
homologous constituents of the true molars. Posteriorly they are associated by a 
strong basal ridge, a jDortion of which exists also at the anterior part of the outer 
lobe, but no portion exists internally and externally as in Entelodon magnum. 

The crown of the penultimate premolar forms a single, large, laterally compressed 
conoidal lobe, resembling very much that of a corresponding carnivorous tooth. It 
is relatively greater antero-posteriorly, and is narrower than that of Choeropotamus, 
and is very much like that of Entelodon magnum; but, judging from Gervais's sketch 
of this tooth of the latter, is more uniform in its transverse diameter. Externally 
it is convex, and in its direction downward curves slightly backward. Its anterior 
margin is convex, but posteriorly it presents a salient margin separating the external 
and internal faces. Posteriorly, the internal face towards the base of the crown is 
rugged, and anteriorly it presents a portion of a basal ridge, which forms a double 
festoon downward. 

.The enamel of the molar teeth of Archaeotheriitm is everywhere corrugated, but 
this appearance wears off as age advances. 

In the trituration to which the true molars ai'e subjected, the enamel at the 
apices of the lobes is first worn through, and the exposed dentine afterwards extends 
across the latter in transverse tracts. 

The posterior two premolars, in the specimen upoii which the species was origi- 
nally established, exhibit the result of considerable mastication. In the last pre- 
molar the posterior basal ridge is partially worn away, and the anterior portion of 
the same ridge and the division between the lobes are completely obliterated. The 
triturating surface in its present condition, presents a broad, transversely ellipsoidal 



04 ARCIIAEOTHEKIUM. 

disk of dentine, communicating by means of a narrow isthmus Avith a smaller 
disk, of the same form as the former, at the base of the anterior margin of the 
outer lobe. In the penultimate premolar the apex of the crown is worn off, leaving 
a subcircular dentinal surface continuous with a narrow tract, extending the length 
of the posterior margin. (IX. 3, 4.) 

The upper true molars of Archaeotherium, and the last premolar are inserted by 
three fangs; two external and nearly vertical, and a third internal, which is broad, 
and is apparently composed of two portions confluent. The penultimate premolar 
is implanted by two fangs, which are nearly vertical, and are placed one before the 
other. 

''' Inferior Molars. — (VIII. 2 ; X. 2, 3.) Of the lower molar teeth of Archaeotherium 
we have the true molars and the last premolar; but we have no opportunit}' of 
comparing them with figures of the corresponding teeth of Entelodon. 

The crowns of all the true molars possess the same form, and differ only by 
successively decreasing from behind. They are oblong oval, and constricted at the 
middle, and are composed of two transverse pairs of conical lobes, with wrinkled 
sides. Posteriorly they are bounded by a conical tubercular heel, which relatively 
is not better developed in the last of the series than in those in advance; and 
anteriorly below the confluence of the lobes they are embraced by a thin basal 
cingulum. 

A remarkable peculiarity of a generic character in these teeth is a transverse 
division of the apex of the antero-internal conical lobe, apparently as if this was 
composed of a confluent pair. 

The last permanent premolar is constructed upon the same plan as the penulti- 
mate premolar of the upper jaw. The crown is large, transversely compressed 
conoidal, and slightly curved backward, and is bounded anteriorly and posteriorly 
by a salient margin. At the base posteriorly a ridge exists with a festooned pro- 
longation on each side, and antero-internally a smaller and excavated talon exists 
with an outer simple and inner double festoon. 

The inferior true molars are inserted by two broad fangs placed one before the 
other, and consisting each of a connate pair ; and the last premolar also has two 
fangs, but these are simple in their form. 

Temporary Dentition. — (VIII. 1,2; IX. 1.) As in the Hog, the anterior two 
permanent true molars are fully protruded before the deciduous molars are shed, 
from which fact, together with the evident suilline character of Archaeotherium, it 
is reasonable to suppose the order in succession of the permanent to the caducous 
dentition is the same as in the former animal. 

The upper temporary true molar resembles the upper permanent true molars, 
but it is very oblique antero-internallj^, and all the lobes of the masticating surface 
except the two external are quite rudimentary. At the base of each outer lobe 
externally there exists a festooned ridge. 

The penultimate deciduous tooth has an antero-posteriorly elongated, trihedral 
crown ; the posterior half of which is the broader, and is composed of a transverse 
row of three lobes, as in the true molar behind it, except that the internal one is 



ARCHAEOTHERIUM. 



65 



as well developed as that external ; and the anterior half forms a quadrilateral 
pyramid, more elevated than the lobes behind. 

The deciduous true molar with its anterior portion broken away is contained in 
one of the fragments of a lower jaw, and is sufficiently perfect to show it keeps up 
the suilliue character of the animal, in having an additional pair of conical lobes 
to the normal number of the permanent true molars. 

The enamel of the deciduous teeth is thinner and less corrugated than that of 
the permanent teeth. 

The species is named in honor of the late distinguished Dr. Samuel George Mor- 
ton, of Philadelphia. 

MEASUREMENTS. 



(^Takcn from the young specimen.') 

Distance from meatus auditorius to the infra-orbital foramen . 
Distance from meatus auditorius to the lachrymal tubercle 
Breadth of head at the transverse fronto-malar suture . 
Greatest breadth at lowest part of ossa nialarum .... 

Length from occipital condyles to anterior part of penultimate premolar 

Distance inferiorly between the glenoid articulations 

Greatest breadth inferiorly of the temporal fossai 

Greatest length inferiorly of the temporal fossce .... 

Narrowest part of inter-tcmporal region ..... 

Greatest breadth at squamous suture ...... 

Breadth at lachrymal tubercles ....... 

Breadth at posterior margin of infra-orbital foramina 
Breadth of hard palate between the middle true molars 



Lines. 


Incbes 


8 


6 


5 


9 


7 





8 


9 


10 





4 


6 


3 


8 


3 


6 


2 


3 


2 


9 


4 


1 


2 


8 


1 


5 



SUPERIOR MOLARS. 



Diameter of seventh molar 
Diameter of sixth molar . 
Diameter of fifth molar . 
Diameter of fourth molar 
Diameter of third molar 
Diameter of last temporary mo' 
Diameter of penultimate molar 



Antero-posterior. 


Transverse. 


9 J lines. 


9 lines. 


11} " 


Hi " 


10 " 


10 " 


91 " 


9 " 


12i " 


7 " 


10 " 


8 " 


Hi " 


7} post. 4 ant 



INFERIOR MOLARS. 



Diameter of seventh molar 
Diameter of sixth molar . 
Diameter of fifth molar 
Diameter of fourth molar . 



12 lines. 


8 lines 


12 " 


8J " 


lOJ " 


7i " 


12} " 


6 " 



66 ARCHAEOTHEEIUM. 



Ai'chaeollieriiiin {Entehdon?) robustiiiii, Leidy. 

(Plate X., Figs. 8-13.) 

Ardodon, Leidy: Proc. Acad. Nat. Sci., 1851, v. 278. 

Archaeotherium rohustum, Leidy: Owen's Rep. of a Geol. Surv. of Wise, etc., 572, 

This species is proposed upon fragments of the crowns of the posterior two 
molars of the left side, and a portion of the crown of a canine tooth probably of 
the left side inferiorly. 

These specimens, which belong to the collection obtained by Mr. T. A. Culbert- 
son, I at tirst supposed indicated the existence of a genus allied to the Bear; but 
by comparison, they have since been determined to belong to a species of Ardiaeo- 
therhim larger than that described in the preceding pages. 

The fragments of molars (X. 10-13) are almost identical in their form with 
the corresponding portion of the same teeth of Archaeotherium Morloni, except that 
in the last molar the posterior basal ridge rises into a conical eminence or fifth 
lobe, which is more regular, but less prominent, and more expanded at the base than 
those in advance. The teeth have been almost a fourth larger than those corre- 
sponding of Archaeotherium Morioni. 

The fragment of the crown of a canine (8, 9) resembles more that of the Bear 
than that of any existing ungulates. It is curved conical in form, and presents a 
slight longitudinal ridge defining its outer and inner faces. It is completely covered 
with enamel, Avhich is thinnest at the inner face, and is unworn in the specimen. 



CHAPTER II. 

DESCRIPTION OF UNGULATA IMP ARIDIG AT AT A. 

Fam. 1. — SoLiPEDiA. 
Gen. AI^'CHITHERIUM, Meyer. 

Under the name of Palaeotherium aurellaiiense, M. De Blainville has inckided 
also the Palaeotherium monspessulanum, and the Palaeotherium egiii/mm, Lartet, 
seu hippoides, De Blainville/ These, according to the view of M. De Christol, 
(Comptes Rendus, vol. xxiv., p. 374,) do not belong to the genus Palaeotherium, 
but to a soliped, to which the name of Hipparitherium is given. In regard to this 
animal, he observes, " Ses os des membres ressemblent a un tel degre a ceux de 
I'Ane et du Cheval, qu'on en trouve une description tres etendue et tres-rigoureuse 
dans les traites d'anatomie veterinaire, et qu'on pent suivre sur ces os de pretendus 
Palaeotheriums les descriptions myologiques des veterinaires aussi completemeut et 
aussi surement que sur une squelette d'ane ou de cheval." 

H. von Meyer had already placed this species in a new genus under the name of 
Anchitherium Ezquerrae," which generic name is adopted by M. Pomel, in his classi- 
fication of the Palaeotheria, as a subgenus.^ 

As a result of these investigations the specific name of the animal is Anchithe- 
rium aurelianense, Gervais. 

A second species, the Anchitherium Dumasii,^ has been indicated by Gervais fiom 
the eocene formations of France. 

Ancliif hei'iiiiu Bairdii, Lgidy. 

(Plate X., Figs. 14-21 ; XI.) 

Palaeotherium Bairdii, Leidy. Proc. Aead. Nat. Sci., 1850, v. 121. 
Anchitherium Bairdii, Leidy: Owen's Rep. of a Geol. Surv. of Wise, etc., 572. 

Among the fossil remains collected by Mr. Alexander Culbertson were the 
greater portion of a skull and fragments of jaws with teeth, of a species of Anchi- 
therium. The teeth of this so closely resemble those represented in De Blainville's 
Osteographie, under the name of Palaeotherium hippoides, that they might readily 



' Ostewgraphie : Palaeotherium, 75. " JabrbucL fUr Mineralogio, 1844, 298. 

' Bui. Soc. Geol. .de France, vii. 219. * Comptes Rendus, xix., 381, 572. 



(58 ANCHITIIERIUM. 

be considered to belong to the same species, were it not that those of the Nebraska 
animal, which I have called AncIiUherium RiirdU, are only about three-fifths the 
size of those of the former. 

The specimens which we have an opportunity to study are as follows: — 

1. The cranium proper, with a portion of the face containing on one side the last 
two and on the other the last three molars. The zygomata and post-orbital arches 
are broken away. The specimen was accompanied by several fragments of a lower 
jaw, of which two contain the last two molars, and one has the coronoid process 
nearly entire. 

2. Both sides of the upper and lower jaws containing nearly all the molar teeth. 

3. Three small fragments of lower jaws of different individuals, containing teeth. 
The Anchliherhan Bairdii, as indicated by the specimens, was rather more than 

half the size of the AncJutherium aurelianense. 

Description of the Head. — The cranial specimen is particularly important from its 
being the first 3'et discovered of the genus Anchiiherium. In its form it is remark- 
ably like that of the corresponding portion of the skull of the Ilorse, and presents 
but few jjoints of resemblance to the Palaeotherium, to which genus it has been 
supposed to belong. 

Lateral Yieio. — (XI. 1.) The skull of AncJiitherium appears relatively shorter 
than that of the Horse; as, in the specimen under examination, the molar teeth are 
much less advanced in their position than in the latter; the last of the series 
being placed below the middle of the orbit. 

The upper outline of the cranium proper, as in the Horse, is convex, and the 
temporal fossa has the same form and relative convexity ; and posteriorly it mounts 
in the same manner upon a low sagittal crest. The summit of the inion and the 
posterior boundary of the temporal fossa are relatively not quite so prominent as 
in the Horse, but as in this, the root of the zygomatic process is implanted about 
the middle of the lower border of the fossa. 

The mastoid portion of the temporal bone is relatively higher than in the Horse; 
and, as in this, impressed upon the parietal bone, there ascends from the squamous 
suture a large, deep, irregular, branched, vascular channel. 

The meatus auditorius is bounded below by a thick auditory process. 

The face is relatively of less depth than in the Horse, arising from the shortness 
of the teeth, compared with those of the latter. Below the position of the orbit 
the alveolar margin is convex antero-posteriorly, as in the Horse. 

The malar bone does not advance as much upon tlie face as in the laiter; its 
anterior suture ascending obliquely from the position of the last molar to the ante- 
rior lachrymal suture. 

In the specimen, the orbits, at their inferior margin are broken away. When 
perfect, their entrance appears to have had almost the same form as in the Horse, 
but was relatively very much larger. They are also more deeply excavated, and 
approached each other much more. Their floor is very extensive, and at its poste- 
rior part forms a thick, obtuse margin, which is situated considerably below the 
level of the sphenoidal bodies. 

Whether a post-orbital arch existed cannot be ascertained from the specimen, for 



ANCHITHERIUM. GO 

in this the process of the os frontis, which, in the Horse, contributes to its forma- 
tion, is broken away to its base, leaving a triangular surface, two sides of which 
measure only three lines, tlie other four lines. 

The lachrymal bone externally is almost as concave as in the vSheep, leading us 
to suspect the existence of shallow larmiers. Its orbital margin is acute, and 
within this, at its lower part, there is a single, vertically oval, lachrymal foramen. 

Sapei'ior Vieio. — (XI. 2.) The upper view of the cranium of Ancldtherium also 
resembles very much that of the Horse. The forehead is a little more flat, and 
extends into a relatively larger triangle posterior to the coronal suture, which holds 
a corresponding position. The anterior margin of the froiitals are not extended 
into long angular processes between the bases of the ossa nasi, as in the Horse, 
but form together a very obtuse angle. 

The sides of the face, as formed by the lachrymal bones and the upper maxillaries 
below them, descend much more abruptly from the anterior orbital processes of the 
ossa frontis, or they approach the vertical line much more nearly than in the Horse. 

In the specimen, the sagittal suture of the frontals and parietals is still open. 

Pusterior View. — (X. 20.) The inion, from its summit being relatively less broad, is 
more triangular in outline than in the Horse. Its middle part bulges over the foramen 
magnum, and above this point is depressed upon each side of a slight vertical ridge. 

The relative position and form of the condyles and the form of the foramen mag- 
num are very much the same as in tlie Horse, except that the inferior surfaces of 
the former are more nearly horizontal, and diverge more posteriorly and approach 
nearer anteriorly. 

Above each condyle, as in the Horse, there exists a crescentic depression of the 
occipital surface. 

Inferior View. — (X. 21.) The basilar process is relatively broader, less deep, and 
more angular than in the Horse, and upon each side it presents a long impression, 
and at the middle is elevated into a superficial tuberosity for muscuhir attachment. 

The junction of the basilar process with the sphenoidal body occupies the same 
position as in the Horse, being on a line with the anterior margin of the foramina 
lacera, but in the specimen it is obliterated. 

The sphenoidal bodies are slightly convex compared with those of the Horse, and 
the posterior does not present the deep muscular impressions existing in that animal. 

The paramastoids hold the same relative position to the condyles as in the Horse, 
and as in this betAveen them a deep fossa exists, at the inner side of which the 
anterior condyloid foramen is situated. 

The OS tympanica is relatively slightly more dilated than in the Horse; and the 
OS petrosa abuts closely against the basilar process. 

The base of the stjdoid process, alone remaining in the specimen, is embraced 
antero-internally by the os tympanica. 

The foramen lacerum is large anteriorly, but becomes a very fine crevice poste- 
riorly. 

The inner portion of the glenoid articulation, which alone is preserved in the 
specimen, resembles very much that corresponding to it in the Horse. The post- 
glenoid tubercle is relatively much more robust; and is mammillary in its form. 
10 



70 ANCHITHERIUM. 

The surface, for attachment of the external pterygoid muscle in advance inter- 
nally of the glenoid articulation, is much less inclined than in the Horse; and at 
the antero-internal part, as in this, it presents a foramen conducting to the fora- 
mina rotundum and spheuo-orbitale. 

The latter, and the optic foramina, are of large size, and hold very nearly the 
same relative position as in the Horse. 

The interpalatine notch, as in the latter, expands as it approaches its bottom, 
which is on a line with the interval of the fifth and sixth molar teeth. 

The hard palate is broken in the specimen, but it appears to have been about as 
much arched as in the Horse, and the exit of the posterior palatine canals is just 
in advance of the sides of the interpalatine notch. 

Inferior Maxilla. — (PI. X., Figs. 18, 19 ; XI. 5, 6.) As in the case of the alveoli of 
upper jaw, corresponding with the shortness of the teeth relatively and compara- 
tively with those of the Horse, the body of the lower jaw of Anchitherinm is 
j3roportionately less deep than in the latter. Its outer side is vertical and slightly 
convex; its base is thiclc and slightly convex forward; and its upper margin 
rapidly ascends posteriorly, and curves in a sigmoid manner more backward to the 
summit of the coronoid process than in the Horse. 

The coronoid process is curved like in ordinary ruminants, but is relatively 
shorter and broader. 

The condyle is very like that of the Horse, but the notch in advance of it is 
relatively broader. 

The ramus, which in the Horse is very slightly depressed externally below the 
position of the coronoid i^rocess, in the fossil is almost as much depressed as in the 
Peccary. 

Deuddon.— (PI X. 14-17, 21; XI. 1, 3-8.) Gervais^ states the formula of the 
dentition of Anchitherium to be : — 

.33 11 ,77 

rn. —- can. ^-^ mol ,^. 

It is extraordinary^ that Ancliitherimn should be so much like Palaeothcrinm in 
the anatomical and physiological construction of its teeth, and yet be so much like 
the Horse in its skeleton. 

The crowns of the molar teeth o^ Anchitherium are entirely devoid of cementum, 
and in the adult are completely exserted. 

The specimens of Anchilherium Bairclii, which we have an opportunity of 
examining, contain in the upper and lower jaws all the molar teeth except the 
first of the series. 

The posterior six upper molars (XI. 3, 4,) are nearly alike in form and size ; the 
crowns, as in those of Palaeotheriwn, consisting of two transverse pairs of lobes. 

The outer lobes, as in the genus just mentioned, are deraiconoidal with triangular 
summits, the basal angles of which are continuous with the extremities of inverted 
U shaped ridges bounding the sides and bases of the external transversely concave 
surfoces. 

The inner lobes are conoidal, and arc prolonged outwardly to the antero-internal 

' Zoolog. et Palacout. Frang., p. 63. 



ANCHITHERIUM. 



71 



side of the outer lobes; in this course becoming dihited into a small conoidal pro- 
cess about the middle. 

These teeth are not bounded by a basal ridge internally, but portions exist ante- 
riorly and posteriorly; and in the latter position inclose a small conoidal process. 

The first upper molar of the normal series is much smaller than the others, as is 
indicated in the specimens by two small fangs, one before the other. , 

The inferior molars (X. 14-17; XI. 5-8,) also are exceedingly like those of 
Palaeotherium. Their crowns are composed of two lobes placed one before the 
other, except the last of the series, which has an additional, or third lobe. The 
lobes are demiconoidal, with their outer side angularly convex and their inner side 
concave and sloping. Their summit is V shaped ; and the posterior extremity of 
this rises to the apex of a pyramidal process of the inner side of the crown. The 
anterior extremity of the summit of the anterior lobes curves to the base of the 
anterior pyramidal process, while that of the summit of the posterior lobe ceases 
upon the outer side of the same process. In the unworn teeth the apex of the 
anterior pyramidal process is indented. The third lobe of the last molar is smaller 
than those in advance, is ovoidal in form, and has a crescentic summit inclosing a 
concave fossa. , 

The inferior molars have no continuous basal i-idge, but a portion exists between 
the bases of the lobes externally, in the form of a small pyramidal tubercle; at 
the anterior part of the crown ; and at the posterior part of the latter, in which 
position it forms an angular process. 

^ The first inferior molar, as indicated in the specimen by a single fang which it 
possesses, is a much smaller tooth than any of those in the series posterior to it. 

The species is named in honor of Prof. S. F. Baird, of the Smithsonian Institution. 



MEASUREMENTS. 

Length of cranium from summit of inion to anterior ext 
Length from occipital condyle to anterior orbital margin 
Length of temporal fossa ..... 

Length of sagittal crest ..... 

Length of ossa froutis ..... 

Height of inion ....... 

Height of face at last molar alveolus . 

Height of orbit from floor to supra-orbital margin . 

Breadth of cranium at para squamosaj . 

Breadth of forehead at anterior orbitar processes . 

Breadth at paramastoids ..... 

Breadth at post-glcnoid tuberosities 
Breadth of hard palate at sixth molares 
Height of body of lower jaw at last molar . 
Height of body of lower jaw at second molar 
Length of upper normal series of molars 
Length of lower normal series of molars 
Antcro-po.sterior diameter fourth upper molar 
Transverse diameter fourth upper molar 
Antero-po.sterior diameter fourth lower molar 
Transverse diameter fourth lower molar 
Autero-posterior diameter last lower molar . 



remity of ossa fr 



ontis 



ches. 


Line 


4 


8 


4 





3 





1 


7 


2 


5 


1 


8 


2 


2 


1 


6 


o 





1 


10 


1 


9 


o 


4 


1 





1 


2 





7J 


2 


11 


3 








6 





71 





6 





4 J 





7 



72 TITAJSrOTHEKIUM. 



Fam. 2. — Imparidigitata Ordinaria. 

TITAIVOTHERIIIM, Leidy. 

Titanotlieriiiui Proiitii, Leidy. 

(Plate XVI. XVII., Figs. 1-10.) 

PaJaeothcriuvi, Prout: Am. Journ. Sci. Arts, 1847, iii., 248, figs. 1, 2. 

Palaeotheriuvi ? Proviii, Owen, Norwood, and Evans: Proc. Acad. Nat. Sci., 1850, v., CG; Leidy: lb., 122; 
Owen's Rep. of a Geol. Surv. of Wise, etc., 551. 
lihinoceros Americainis? Leidy: lb., 1852, vi., 2. 

* 

In the American Journal of Science and Arts for 1847, page 248, Dr. Hiram A. 
Prout, of St. Louis, described and figured the fragment of a lower jaw containing 
the true molars of a huge animal, supposed to be a species of Palceotherium. 

The specimen, which was the first fossil from the eocene cemetery of Nebraska, 
presented to the notice of the world, with another corresponding of the opposite 
side, apparently from the same individual, were kindly loaned to me by Dr. Prout 
for examination. (PI. XVI. Fig. 1.) 

These strongly resemble the corresponding portion of the lower jaw of Palceo- 
tlierium, and if they do not belong to this genus they do to one closely allied to it; 
and if the animal preserved the same relations of size as Palaeotherium magnum it 
Avas more than twice the size of this, which Cuvier has estimated to have been 
over four and a half feet in height at the withers, or equal to the Rhinoceros Si 
Java; less lofty than a large Horse, but stouter, with a more massive head, and 
with extremities thicker and shorter. 

The two fragments of the lower jaw, before assuming their present mineralized 
condition, were very much fractured, and the fissures are now filled up by a hard 
matrix, which also adheres to their exterior surface in a concretionary form. 

Along the true molar series the jaw measures eleven inches; below the middle 
lobe of the last molar it is six inches in depth; and midway below the position of 
the first true molar is nearly two and a half inches in thickness. The sides are 
slightly convex vertically, and the bone is thick and rounded, and descends from 
the position of the last molar towards the posterior broken margin of the specimen. 
Two inches back of the last molar the depth of the fragment is nine and a half 
inches, but its thickness is not so great as it is anteriorly. 

The inferior true molars are constructed upon the pattern of those of Palaeoihe- 
rium; the anterior pair being composed of two, the last of three demiconoidal 
lobes. These have crescentic summits, the extremities of which rise to the inner 
side of the teeth, and there become confluent, and form prominent points. In the 
specimens under examination, the outer side of the lobes of the molars is embraced 
by a strong basal cingulum about two lines in depth. The inner surface of the 
teeth forms a vertical plane, which is slightly convex autero-posteriorly, and does 
not possess the slightest trace of a basal ridge such as exists in the true 
Palaeollierivm. 



TITANOTHERIUM. 73 

The triturating summits of the lobes present more or k^ss broad crescentic sur- 
faces of exposed dentine, bordci'ed by enamel, with the horns rising to the inner 
side of the teeth, and there becoming confluent and forming simple conoidal promi- 
nences. The enamel spaces embraced by the horns of the crescentic summits of 
the lobes do not slope towards the base of the teeth internally, as is represented to 
be the case in the figures of the corresponding teeth of Palaeoiherlum, but they form 
deltoidal concavities, which are nearly on the same level with the dentinal cres- 
cents, and are bounded internally by a thiciv obtuse border; open, however, at the 
middle to the bottom of the concavities. 

The third lobe of the last molar is smaller than those in advance, and resembles 
one of them atroi^hied at its j^osterior half The external basal ridge of this tooth 
ceases upon the third lobe just before reaching its posterior surface; but upon this 
internally a small portion is developed. 

The enamel of the teeth is rugose, and is most so externally, in which position 
it also presents a very uniform series of transverse striae. At the triturating sur- 
face of the teeth externally, where the enamel is thickest, it measures one line and 
two thirds. 

The measurements of the teeth in the fragments of jaw just described, are as 
follows : — 

ANTEKO-POSTERIOR. TRANSVERSE. 

Inches. Lines. Inches. Lines. 

Last molar 4 6 1 10 

Second true molar ........ 3 3 2 

First true molar 2 8 1 10 

In the collection of Dr. Owen, there is preserved a portion of the left side of a 
lower jaw (PL XVI., Figs. 2, 3) containing true molars exactly like those just de- 
scribed, and the fangs of the preceding two premolars. Accompanying this specimen, 
and probably derived from the same individual skeleton, there ai'e also the croAvn of 
the second or third left lower premolar, the crown of a lower canine, and fragments 
of two upper molars. The fragment of lower jaw, before it became infiltrated with 
mineral matter, was very much crushed, and at present it is more light and friable 
than any other of the specimens of fossils which have been brought from Nebraska. 
It is considerably smaller than the corresponding part of the bone in Dr. Front's 
specimens, measuring nine and a half inches along the series of true molars, five 
and a quarter inches in depth below the last molar, and an inch and a quarter in 
thickness below the first true molar. Two inches posterior to the last molar it is 
seven and a quarter inches in depth. Its form closely corresponds with that of 
Dr. Prout's specimens, as does also the form of the teeth contained in it, except 
that their basal ridge is not of uniform depth, but gradually rises in a pyramidal 
manner, and becomes thinner from between the lobes to their most prominent ex- 
ternal part. 

The teeth are more worn than in the specimens of Dr. Prout, and their enamel 
presents the same appearance, but in the same position is a third of a line less in 
thickness. 

The measurements of the true molars are as follows : — 



74 TITANOTHERIUM. 

ANTERO-POSTERIOR. TRANSVERSE. 

Indies. Lines. lucbcs. Lines. 

Last true molar 4 2 1 11 

Second true molar ........ 2 9 1 9 

First true molar ........ 17 

The isolated crown above mentioned of an inferior left premolar (PL XVI. Figs. 
8-10), probably the second, measures only sixteen lines antero-posteriorly, and 
almost an inch transversely, indicating a rapid reduction in size of the teeth from 
behind forward; nevertheless, this is gradual, for the fangs of the last premolar, 
still retained in the portion of lower jaw, on a line with the connection to their 
crown, measure twenty-one lines antero-posteriorly. The inner side (Fig. 10) of 
the specimen of the premolar is a smooth vertical plane; and externally (Fig. 9) 
the basal ridge is deep, but thin, and rises to the most prominent part of the lobes, 
as upon the true molars. The masticating surface (Fig. 8) presents a broad tract 
of dentine bordered by enamel, bilobed externally, and straight internally. 

The crown of the inferior canine (PI. XVI., Figs. 11, 12) is curved conical in 
form, and, in section at its base, is very nearly circular. Internally, its base is 
emljraced by a thick, deep cingulum, with a prominent margin, which exhibits also 
a tendency to pass around the outer side of the tooth. The outer (Fig. 11) and 
inner (Fig. 12) sides of the tooth are defined by a saliance of the surface, and the 
former is uniformly convex and smooth, the latter angularly convex, less broad, 
and less smooth. The enamel is worn off from the point of the tooth, and also 
below this antero-externally over an oval space almost half an inch in length, indi- 
cating that the inferior canine, as in the undoubted Palaeotherium^ occupies a 
position, when the mouth is closed, posterior to the superior canine. 

Measurements of the crown of the inferior canine are as follows : — 

Inches. Lines. 
Cireumference at base .......... 3 

Length of external convex surface ........ 1 7 

Height from the base iuternally . _ . . . . . . .1 2 

Of the two fragments of upper molars above mentioned, one is the internal half 
of the crown of a premolar (PL XVII., Figs. 5, 6), probably the second; the other 
is an internal portion of a true molar (PL XVI., Figs. 6, 7). 

The former specimen measures one inch five lines antero-posteriorly, and its 
masticating surface (PL XVII., Fig. 5), which is very much worn down, presents 
a form intermediate to that in the corresponding tooth of Palaeotlierum macjnum, 
and Aceratlierium incisiciim. Internally (Fig. 6), the crown is transversely convex, 
and is very sloping inwardly from the fangs, so that the tootb has projected very 
considerably internal to the alveolar margin of the palate. This side of the tooth 
is formed by a tliick and deep cingulum, which envelops the bases of the inner 
lobes, and exhibits an obtusely rounded margin, thickest anteriorly. 

The inner lobes, of which the anterior is very much larger than the posterior, 
are confluent, and, in tlie specimen, are nearly worn to their base, and present a 



* Cuvier, Eech. sur les Ossem. Foss., ed. 3, III. 8, 9, Pi. V., Fig. 1. 



TITANOTIIERIUM. 75 

tract of dentine (Fig. 5) extending to the broken margin of the tooth. The exter- 
nal portion of the dentinal surface about its centre, and near the posterior margin, 
is occupied by a pair of trilateral enamel islets, -which are the remains of the termi- 
nations of transverse valleys, such as exist in the molars of Rhinoceros and Palaeo- 
tlierium. 

The fragment of a superior true molar (PI. XVI., Figs. 6, 7) presents a large 
conical protuberance, corresponding to that antero-internal in the Palaeoiherium 
magnum. It has the enamel of its apex just worn through, leaving a discoidal 
surface of dentine about one line in diameter. External to the conical lobe are 
remains of the abraded masticating surface of the outer lobes of the tooth, and at the 
base of the former, there exists one side (Fig. 7) of a deep pit homologous with that 
at the base of the posterior half of the inner face of the antero-external lobe of the 
corresponding tooth in Palaeoiherium magnum. Antero-internally to the base of 
the conical lobe, a thick, obtuse prominence (Figs. 6, 7) exists, which is a portion 
of a basal ridge ; but of this no trace exists on the inner side of the tooth, like that 
in Palaeotherium magnum. 

In Dr. Owen's collection, there are also the isolated crowns of an inferior first 
and last true molar (PI. XVII., Figs. 8-10), apparently from two other distinct 
individuals of the same species as that indicated by the specimens just described. 

The measurements of these are as follows : — 

Antero-posterior diameter of the last inferior molar .... 
Transverse diameter of the last inferior molar ..... 
Antero-posterior diameter of the first true molar .... 

Transverse diameter of the first true molar ..... 

In the collection of Dr. Prout, and accompanying the two portions of a lower 
jaw, which have been the subject of investigation, is a portion of the left superior 
posterior molar, probably belonging to the same species, though not to the same 
individual (PL XVI., Figs. 4, 5). What is preserved of this specimen exhibits a 
strong resemblance to the corresponding part of the homologous tooth in Palaeoihe- 
rium magnum; but it presents several important differences. 

Upon the masticating surface of the crown, the valleys everywhere, antero-poste- 
riorly as well as transversely, are nearly uniform in depth (Fig. 5). 

The summits of the outer lobes have been denuded of their enamel, and present 
the remains of a broad W shaped tract of dentine, while the apex of the antero- 
internal mammillary lobe has not yet had its enamel worn through. 

As in Palaeotherium magnum, at the base of the posterior half of the inner face 
of the antero-external lobe, there is a deep elliptical pit of enamel, and a little pos- 
terior to this is a second smaller and shallower pit. 

The external face of the crown of the superior molars of Palaeotherium, as de- 
scribed by Cuvier, inclines inward as it descends, and is divided by three longi- 
tudinal salient ridges [arretes) into two concavities, rounded towards the Aing, and 
terminating in a triangular cusp at the triturating surface, the basal angles of 
which rest upon the salient ridges. 

In the special subject under investigation, about three-fourths only of the outer 



Inches. 


Lines. 


4 


o 
ii 


1 


7 


2 


10 


1 


10 



76 TITANOTIIERIUM. 

surface of the antero-external lobe (Fig. 4) is preserved, and this does not conform 
to the characteristic appearance of the corresponding portion of the tooth of Palaeo- 
therium. It inclines and terminates below as in the latter, but relatively is only 
slightly concave, and it possesses no bounding salient ridge at its anterior part, 
such as is represented in the figures of the teeth of Palaeotherium in the works of 
Cuvier, Jaeger, De Blainville, Gervais, and others. In the place of such a ridge, 
the tooth forms a prominent convex margin, projecting, as in ruminants, in Rhinoceros 
and. Palaeotherium itself, exterior to the position occujaied by anterior molars, and 
the basal ridge winds around the prominent margin to the anterior part of the 
tooth, descending to its masticating surface, which it reaches, in the specimen, a 
half inch internal to the outer edge of the latter. 

The dimensions of the tooth, so far as they can be ascertained in its present con- 
dition, are as follows: — 

Inches. Liues. 
Distance from the apex; of the antero-internal lolie to tliat externally of tLe 

antero-external lobe .......... 1 

Height of latter from base to point. ........ 2 2 

The enamel of the specimen just described is smooth upon the masticating sur- 
face, and at the base of the antero-internal conical lobe is about one line in thick- 
ness. On the outer side of the antero-external lobe it is rugose, and at the external 
masticating mai'gin of this is also about one line in thickness. In other positions 
it is thinner, especially where it iuA^ests the inner sides of the outer lobes, the 
bottom of the antero-posterior valley, and the deep pits. 

The various fragments of lower jaw and teeth above described, though exhibiting 
a very great resemblance to the corresponding parts of the Palaeotherium magnum, 
are yet sufficiently diflerent to indicate they probably belong to a distinct but 
closely allied genus, for which the provisional name of Titanotherium is proposed. 
The most important differences, which have been presented, are the absence of a 
basal ride at the inner side of the inferior molars, and at the same side of the frag- 
ment of a superior true molar; the nearly uniform depth of the antero-posterior 
and transverse valleys in the upper true molars ; and the absence of the salient 
ridge, characteristic of Palaeotherium, at the anterior margin of the antero-external 
lobe of the last superior molar. 

In the collection of Mr. Thaddeus A. Culbertson, there are the crowns, nearly 
whole, of two superior premolars (PI. XVII., Figs. 1-4), and fragments of two 
others, which also probably belong to Titanotherium Proutii. These, I stated in a 
verbal communication to the Academy of Natural Sciences, probably belonged to 
a species of Rhinoceros, for which the name R. Americanus was proposed,^ but they 
certainly do not belong to this genus, though closely partaking in its chai-acters 
those of Palaeotherium. 

The nearly perfect crowns of the superior premolars are quadrate, and are 
greater in their transverse diameter than antero-posteriorly. Their outer side 



» Proc. Acad. Nat. Sei., VI., 2 



TITANOTHERIUM. 77 

(XVII. 2) presents a btisal ridge, descending at its anterior and posterior margin to 
the masticating surface ; but it does not possess a median salient ridge like that of 
Palaeotherium, nor does it present the anterior characteristic fold of the Rhinoceros. 
The portion of this surface corresponding to the posterior lobe inclines inward, in 
its coui'se downward, and the anterior portion of the same surface rises into a 
median longitudinal prominence, descending to the apex of the anterior lobe. 

The inner side (1) of the teeth is transversely convex, and forms a thick and 
deep cinguhun, with a wide, obtusely rounded border, enveloping the bases of the 
inner lobes. * 

The latter, of which that anterior is very much the larger, are confluent their 
entire height, and are isolated from the outer lobes nearly to their base ; thus de- 
stroying the principal transverse valley as it usually exists in the molars of lilii- 
noceros and Palaeotherium, and creating one antero-posteriorly (3, 4). 

The antero-posterior valley, at the position corresponding to the depressed in- 
terval of the outer lobes, communicates with a large and deep trilateral pit, homo- 
logous with the termination of the principal transverse valley in the molar teeth of 
JRhinoceros, and Avith a similar pit in the teeth of Palaeotherium. Posteriorly this 
valley is connected with another, but smaller and shallower pit, which also finds 
its homologue in the Rhinoceros and Palaeoihei-ium. In one of the specimens (4), 
probably the third premolar, the antero-internal lobe is more confluent with the 
corresponding outer lobe than in the other; and its internal cingulum is more 
irregular. 

In the trituration to which these teeth have been subjected, the enamel has been 
worn off from the masticating surface of the outer lobes, very nearly to the base 
of those within, leaving a broad tract of exposed dentine, which is bilobed inter- 
nally by the deep central enamel pit. In the su2:)posed third premolar (4), this 
tract is continuous, anteriorly upon the summit of the antero-internal lobe, but in 
the fourth premolar, the summits of the inner lobes present a separate antero-pos- 
terior tract. 

The enamel of these teeth, except where worn, is slightly rugose, and, upon the 
outer lobes, externally exhibits numerous transverse undulating lines. It is thickest 
upon the inner lobes, where it is one line and a half; and upon the external part 
of the outer lobes it is about one line in thickness. 

The measurements of the two specimens, in their present condition, are as 
follows : — 

Inches. Lines. 
Antero-posterior diameter of third premolsh- '...... 2 5 

Transverse diameter of third premolar ....... 1 10 

Antero-posterior diameter of fourth premolar ...... 2 7 

Transverse diameter of fourth premolar ....... 1 9 

One of the fragments of the premolars above mentioned, exhibits the inner lobes 
entirely associated as one, and disconnected to their base from the outer lobes. This 
connate lobe has the form resulting from the confluence of an anterior larger cone, 
with another posterior and smaller (7). The sides of the connate lobe, where not 
affected by attrition, are rugose, and the summit presents a clavate tract of dentine 
with a border of enamel nearly one line and a half in thickness. 
11 



78 PALAEOTHERIUM. 

The antero-posterior diameter of the tooth to which thjs fragment belonged, is 
one inch ten and a half lines. The specimen still retains a portion of the internal 
basal cingulum, extending anteriorly and posteriorly, and also portions of the two 
enamel pits with the intervening antero-posterior valley of the tooth. 

The other fragment of a premolar, alluded to, consists of the fangs and a portion 
of the outer lobes, which exhibits the same peculiarities as those already described. 

Dr. Evans states, in the report of Dr. Owen, previously quoted, that the remains 
of the PaJaeoiherlam ( TUanutherkun) Pi-oidii were found in a green, argillo-calcareous, 
indurated stratum, situated within ten feet of the base of the geological section. 
(See page 13 of this memoir.) He observes : "A jaw of this species was found, 
measuring, as it lay in its matrix, five feet along the range of the teeth, but in such 
a friable condition that only a portion of it could be dislodged; and this, notwith- 
standing all the precautions used in packing and transportation, fell to pieces." 

" A nearly entire skeleton of the same animal was discovered in a similar posi- 
tion, which measured, as it lay imbedded, eighteen feet in length, and nine feet in 
height." 

The specific name applied to the animal whose remains have just been described, 
was proposed in a letter to the Academy of Natural Sciences, of Philadelphia, by 
Drs. Owen, Norwood, and Evans, in honor of Dr. Iliram A. Prout, of St. Louis, 
Avho first indicated its existence. 



PAltAEOTHERIUlfl, Cuvif.r. 
Palacotheriiiiu g:ig'nntcuin, Leidy. 

(Plate XVII., Figs. 11-13.) 

In the collections of Messrs. Culbertson and Dr. Owen, there are several frag- 
ments of molar teeth of an animal equally huge with the Titanotlierium, and most 
probably belonging to a species of Palaeotheriiim, which was twice the size of the 
Palaeothermm magnum. 

The fragments, of which there are five, are only single external lobes of the 
upper molars. These, externally, correspond to the description of Cuvier of the 
teeth of Pulaeotherium. A conjoined pair of the lobes forming the outer part of a 
tooth, "present the external face strongly inclined inwards in descending, and divided 
by three salient ridges into two concavities, Avhich are I'ounded towards the fangs, and 
terminate in a triangular cusp at the masticating surface, the basal angles of which 
rest upon the termination of the salient ridges." The median ridge is a thick 
obtuse fold outwards of the tooth, and the anterior and posterior ridges are acute, 
roughened offsets from the basal ridge, descending to the masticating surface. 

The measurements of the more perfect specimens are as follows : — 

Inches. Lines. 

Lengtli of the longest lobe ......... 2 4 

Length of a second specimen ......... 2 

Breadth of the second specimen at the basal angles of the cusp . . .1 8 

Length of the shortest lobe ......... 1 7 

Breadth of the shortest lobe at the basal angles of the cusp .... 1 3 



RHINOCEROS. 79 



RHIi\OCERO^, Linnaeus. 



The existing species of Rhinoceros are confined to Africa and Asia, and the 
Islands of Java and Sumatra. A vast quantity of remains of extinct species liave 
been discovered in Great Britain, the continent of Europe, Siberia, and the Hima- 
layas, but, until the region of Nebraska had been visited, no traces of the genus 
had been found in America.^ 

The number of extinct species Avhich have been proposed, frequently upon the 
slightest characters, is so great, that the ciiticism of De Blainville upon their 
authors appears to be quite just: "Qui semblent considerer les os comme des in- 
dividus, comme des ma.sses minerales, sans considerations biologiques ou physio- 
logiques ; en sorte que les especes se creent chez eux, pour ainsi dire, au compas."" 

Among the fossil remains discovered at Nebraska, are those of two species of 
Rhinoceros, certainly different from any of those found in other parts of the globe. 
The larger of the tvro species, as indicated by an almost entire skull, was nearly 
three-fourths the size of the Rhinoceros indicus, or it was about the size of the 
Rhinoceros minutus, Cuvier, which is regarded by De Blainville as a small variety 
of the Rhinoceros incisicus. The other was less than two-thirds the size of the for- 
mer species, and is thei'efore the smallest Rhinoceros which has ever yet been indi- 
cated. 



» In the Monthly American Journal of Geology, etc., 1831, p. 10, the editor, G. W. Featherstonhaugh, 
has given a description of what he considered to be the fragment of a jaw, containing two incisor teeth of 
an animal closely allied to the Rhinoceros, found in Pennsylvania. Mr. Featherstonhaugh observes: "The 
mineral composition of this fragment gives it a very anomalous character, and is a circumstance entitled to 
the particular consideration of geologists. There is nothing of the nature of bone about it, except its 
form ; the whole substance, the teeth included, being constituted of an aggregate of quartzose particles, 
and presenting the appearance, not of a gradual substitution by mineral infiltration to osseous matter, but 
of a cast of part of a jaw and teeth formed of small quartzose grit, and giving a semi-translucency to the 
teeth, which is wanting to the more opaque jaw." 

Dr. Harlan, in his Medical and Physical Researches, refers to this specimen, page 208, and says : " For our- 
selves, we are disposed to wait for further discoveries of this nature, previous to admitting the present specimen 
as part of our fossil fauna. The specimen is no less singular or interesting to geologists, as demonstrating 
the very close analogy of a mere hisus naturse of the mineral kingdom, if it be nothing else, to a portion 
of the animal skeleton." Dr. Harlan further remarks, in a note : " The original specimen was sent to Lon- 
don, and the geologists who there examined it, considered it of too doubtful a character to be admitted as 
a fossil remnant." 

De Blainville, in his Osteographie, page 172, in reference to this specimen, says : " Ce n'est pas lo lieu 
de diseuter ce point au moins fort contestable; mais comme la piece en nature fait aujourd'hui partie des 
collections du Museum, nous pouvons assurer qu'elle ne resemble pas lo moins du monde ;\ un fragment 
de machoire de Rhinoceros, ni pour le corps de I'os, ui pour les dents pr^tendues. C'est sans doute une 
pi6ce artificielle, une grossiere supercherie. II est done v^ritablement a regretter qu' on en ait hasarde et 
exprime la pensiSe; et que tons les catalogues de paleontologie aient inscrit une espece de Rhinoceros fossile 
en Amerique, sans meme une expression de doute." 

In addition, my friends Dr. I. Hays, and Mr. I. Lea, have informed me they had seen the specimen, and 
had always regarded it as a mere mineral fragment. 

' Osteog. Gen., Rhinoceros, 212. 



80 RHINOCEROS. 

I was at one time disposed to consider the two species of Nebraska Rhinoceros as 
having belonged to the subgenus Aceratherium, Kanp, from the fact that in one of 
the specimens, upon which the larger species was established, the upper part of the 
face, as far forward as the position of the second molar tooth, presents no indica- 
tion of an advancing rise to produce a prominence or boss at the end of the nose 
for the support of a horn. In the specimens of the smaller species, the face is too 
much mutilated to obtain any idea of its form, but from the resemblance of the 
back part of the cranium and the lower part of the face to those of the larger 
species, I supposed the similarity probably continued in the I'emainder of the face, 
and thus indicated the species to be of the same subgenus as the other. Upon 
more mature reflection, I am inclined to think both species of Rhinoceros of Ne- 
braska possessed a horn upon the end of the nose, for although this portion of the 
face is not preserved in any specimens to determine the fact, yet the consti'uction 
of the remaining portion of the face is more after the type of that of the true 
Rhinoceros than that of the Aceratherium. In this, according to the representation 
by Kaup (Fig. 2, Tab. X. of the Ossem. Foss.), the lateral notch of the anterior 
nares extends as far back as the commencement of the fifth molar tooth ; or, as 
represented by De Blainville (Ost. Gen., Khin., PI. IX.), (who regai'ds the Acera- 
therium incisivum as the female of the Rhinoceros incisivus, Cuvier, with which the 
name is synonymous), as far as the fourth molar tooth, thus leaving little width to 
the face from this point to the orbit, and a feeble support to the nasal bones from 
the ossa maxillaria, necessary to afford a firm basis to a nasal horn. On the con- 
trary, in both species of Nebraska Rhinoceros, the lateral notch of the nares does 
not extend beyond the position of the first molar tooth, thus producing a great de- 
gree of relative breadth to the face, and an ample support laterally to the nasal 
bones, so as to enable them to sustain the horn, which probably tipped the nose. 
Both species of Nebraska Rhinoceros, at most, were unicorn, for the forehead is 
slightly depressed and smooth, and presents neither boss, elevated roughness, nor 
other indication of the existence of a frontal horn. 

In the form of the upper molar teeth, the #pecies of Nebraska Rhinoceros re- 
semble the Aceratherium incisivum more than they do recent species of Rhinoceros, 
especially in the existence of a well-developed basal ridge on the inner side of the 
premolars. 

In the smaller species of Nebraska Rhinoceros, incisor teeth existed in both jaws 
in the adult, as indicated in two specimens by small remaining fragments of the 
fangs, and it is probable that they also existed, under the same circumstances, in 
the larger species, although this is proved only for the upper jaw, one of the speci- 
mens of which yet preserves a portion of an incisive alveolus in the intermaxillary 
bone. 



RIIINOCE'ROS. 81 

Rliiiiocei'Oi^ Occidenfalis, Leidy. 

(Plates XII., XIII.) 

Hhiiwceros occideiitalis, Leitly: Proc. Acad. Nat. Sci., 1850, v., 119; lb. 1S51, 27G ; Owen's Rep. of a Geol. 

Surv. of Wise, etc., 552. 
Aceraiherium, Leidy: Proc. Acad. Nat. Sci., 1851, v., 331. 

The materials which we have in possession to describe the larger species of Rhi- 
noceros from Nebraslca, are as follows : — 

1. A skull, with the right superficial portion and end of the nose broken away, 
and otherwise much fractured and mutilated. It contains upon the left side all 
the molar teeth except the first, which fortunately exists upon the other side ; but 
all the remainder are broken. From the collection of Dr. D. D. Owen. 

2. Two fragments of lower jaws, from two other individuals; one containing the 
last two molars, the other the posterior three molars, except the last. From Dr. 
Owen's collection. 

3. Nine fragments of as many upper molars, and eight small fragments of lower 
jaws, only two of which contain perfect teeth ; apparently from three or four dif- 
ferent individuals. From the collections of Messrs. Culbertson and Capt. Van Vliet. 

The species was originally established upon several small fragments of molar 
teeth, procured by Mr. A. Culbertson, and its existence was afterwards confirmed 
by several entire molars brought home by Mr. T. A. Culbertson. 

Description of the Skull. — The skull in the collection of Dr. Owen, is about three- 
fourths the size of that of the Rhinoceros indicus. Its upper part and left side, with 
the corresponding molar teeth, are comparatively well preserved. The specimen is 
an adult one, though it did not belong to an old individual, for all the molars are 
protruded, but in none is the enamelled triturating surface obliterated. 

Lateral View. — (PI. XII. Fig. 2.) One of the most remarkable features of the 
species is presented in the side view of the skull, viz. : the verticality of the inion, 
with the slight degree of inclination forward of the upper part of the head. In- 
deed, the latter is so nearly horizontal, that, in comparison with the skull of Rhino- 
ceros indicus, it appears as if the two extremities of the head had been depressed, or, 
in other words, as if the head had been forcibly made straight. In connection with 
the peculiarity just described, a relatively large proportion of the temporal fossa is 
situated posteriorly to the root of the zygomatic process, which holds a position 
about the middle of the fossa, whereas in Rhinoceros indicus it is placed at the pos- 
terior third of the latter. 

The zygomatic process extends from its root less outwardly, but rises more than 
in Rhinoceros indicus. Its upper margin slopes forward more than in the latter, 
and the upper surface of its root is nearly horizontal. The outer surface is vertical 
and convex; but anteriorly, or where the malar bone contributes to the formation 
of the zygoma, it is flat. The deepest ])ixvt of the zygoma is just in advance of the 
glenoid articulation, and measures about two inches. 

The meatus auditorius is vertically ovate, with tlie narrow part downward. 

The temporal fossa has almost the same relative extent as in Rhinoceros indicus, 



g2 RHINOCEROS. 

but it is longer, and less deep vertically. Superiorly, it is bounded by an acute 
rido-e, diverging from the median line to the post-orbitar pi'ocess. The parietal 
crest formed by tlie contiguity of this ridge of each side is broad and strong, and 
includes a median angular groove. 

From the temporal surface, inclining to the middle, line of the cranium, it appears 
more oblique than that of Rhinoceros indicus, but for two inches and a half above 
the zygomatic root it is nearly vertically convex. In advance of the root of the 
zygomatic process, the temporal fossa appears more deeply excavated than in the 
last mentioned species ; and anteriorly it is better defined from tlie orbital cavity 
by a prominent pyramidal ridge, which proceeds in a curved line inward and back- 
ward from the post-orbital process to the position of the spheno-orbital foramen. 

The side of the face from the post-orbital process forward is vertical. The orbit 
is excavated more transversely and deeply than in Rhinoceros indicus, and its ori- 
fice is better defined. The entrance constitutes three-fourths of a circle, and is 
bounded above by a very prominent supra-orbitar process, which is formed by the 
confluence of the antero- and post-orbitar processes. The surface of the supra- ' 
orbitar process is convex and rough, and its lower margin slightly overhangs the 
inferior edge of the orbit. The vertical diameter of the entrance of the orbit is 
two inches and a quarter ; and it is defined below by a small pyramidal process at 
the junction of the malar bone with the zygomatic process of the temporal. The 
floor of the orbit is deeply concave, and terminates posteriorly by an abrupt convex 
margin. The lachrymal bone and foramen are too much broken to judge accu- 
rately of their form, but there appears to have been a single one of the latter, rela- 
tively of large size. The lachrymal process was small and rough. The face in 
advance of the orbit is much fractured in the specimen. It is relatively longer 
than in Rliinoceros indicus, and is quite vertical the entire extent. The greater 
portion of the infra-orbitar foramen is broken away, but sufficient remains to show 
its position to be about one inch and a half above the interval of the second and 
third molar. From a fragment of the left intermaxillary bone being preserved, it 
may be determined that the notch of the anterior nares was relatively short, com- 
pared with that oi Rhinoceros indicus ; and this bone is stronger, and is articulated 
by a finer serrated suture. It rises much more than in Rhinoceros indicus, its pos- 
tero-superior extremity being even above the middle line of the face, or it is on a line 
with the inferior suture of the lachr3'mal bone, which is above the inferior margin 
of the orbit. The maxillo-intermaxillary suture is only a half an inch below the 
anterior portion of the naso-maxillary suture. 

The intermaxillary fragment retains the bottom of the corresponding incisive 
alveolus, and this is just twenty-two lines from the posterior extremity of the bone 
in which it is situated, or is one inch and a quarter from the upper portion of the 
maxillo-intermaxillary suture, and presents some idea of the relative position of the 
incisive teeth compared Avith those of Rhinoceros indicus. So far as can be ascer- 
tained, the hiatus in advance of the molars to the intermaxillarj' bone has been 
about one inch and a half. 

Superior Vieio. — (PI. XIII. 1.) The upper view of the head presents an extensive, 
depressed, trapezoidal surface. Commencing posteriorly as an angular groove, in- 



KHINOCEROS. 83 

eluded by the two ridges forming the parietal crest, it gradually expands forward, 
and, between the suprtvorbitar processes, measures in its perfect state seven inches 
in breadth. On each side of the forehead above the anterior part of the orbits, and 
extending a short distance upon the nose, it is prominent and convex ; but in the 
middle of the forehead, and upon the nasal bones, which incline slightly at their 
upper surface towards each other, it is transversely concave. Upon the forehead, 
in the specimen, are three slight exostoses. 

The fronto-nasal suture is doubl}^ crescentic with the conjoined horns directed 
forward. The lateral margins of the ossa nasi converge anteriorly, and are a little 
concave, but vertically are convex, and the naso-maxillary suture has been about 
three inches and a half in length. 

Posterior View. — In examining the head from behind, the remarkable degree of 
lateral compression of the cranium in comparison with that of the Rhinoceros in- 
dicus is a striking feature of the species. The inion is exceedingly narrow in 
comparison with that of other species of Rhinocei-os, and the occiput, in a corre- 
sponding degree, bulges out posteriorly, so that, in the median line, it projects at 
least an inch back of the position of the condyles. 

In a corresponding degree with the narrowness of the cranium this is elongated, 
so that neither its capacity nor its surfaces for muscular attachment are less than 
in existing species of Ehinoceros. 

In the specimen, the occipital foramen and condyles are too much broken to 
judge accurately of their form. The former appears to have been vertically oval, 
and not so much notched above as in Ehinoceros indicus ; and it measured about one 
inch and a half in its long diameter, and one and a fifth in breadth. The condyles 
appear not to have differed in form from those of recent species of the same genus. 

Inferior Vieio. — (PI. XII. 1.) The base of the skull is more nearly horizontal than 
in recent species of Ehinoceros. 

A portion of one condyle, preserved in the specimen, indicates the position of the 
condyles to be more vertical than in Ehinoceros indicus. The angle of their arti- 
cular surface is also moi'e abrupt, is lateral, and nearly vertical. The posterior 
portion of the articular surface is dii'ected backward and relatively slightly upward ; 
the inferior portion forward and outward, or much less downward than in Ehino- 
ceros indicus. 

The basilar process in advance of the condyles is narrow, measuring a little over 
an inch only between the anterior condyloid foramina. It is elevated in the median 
line into a prominent acute crest, which is pyramidal posteriorly, and serves as a 
sort of abutment to the inferior termination of the condyles, and anteriorly it 
gradually decreases and vanishes at the prominent junction of the process with 
the post-sphenoidal body. The sides of the basilar j)rocess are concave antero-pos- 
teriorly, and form, between the condyle and the para-mastoid process, a deep con- 
cavity, at the anterior part of the bottom of which the condyloid foramen is situated. 

The para-mastoid processes are broken in the specimen, and they appear to have 
been relatively small in comparison with those oi Ehinoceros indicus; projecting, as 
they do, very little below the mastoid processes, which are much more robust in 
their proportions. 



84 IIHINOCEROS. 

The foramen lacerum is relatively small compared with that of Rldnoceros indicus, 
and tlie foramen ovale, which is distinct from it, is situated on a line internally 
with the glenoid articulation. 

The latter antero-posteriorly in comparison with its breadth, is relatively greater 
than in Rhinoceros indicus, and is directed more outwardly, and at its postero- 
external portion is more depressed. 

The post-glenoidal tubercle is relatively short, thin, and broad compared with 
that of Rhinoceros indiciis. It is obliquely compressed, and has one broad surface 
directed backward and inward ; the other, forming part of the articulation, present- 
ing outward and forward. 

As in Rldnoceros indicus, the root externally of the pterygoid processes, is tra- 
versed by a short but large canal, into which opens a foramen representing the 
associated foramina rotundum and spheno-orbitale. 

The passage to the posterior nares, between the pterygoid processes and vertical 
plates of the palate bones, has about the same relative extent as in Rhinoceros 
indicus. 

The hard palate in the specimen is very much fractured, but the parts appear 
to have retained their natural relative position ; and it is remarkable for its deep 
and narrow arched form. The molar teeth, in a nearly sti'aight line upon each 
side, converge anteriorly, and are distant between the first premolars only nine 
lines, and between the anterior lolies of the seventh molars twenty-two lines. 
The inner sides of the molars, in advance of the posterior two, project internally 
beyond the alveolar margin, and gradually increase in this disposition to the first 
premolars, so that the passage between these latter and the hard palate forms 
nearly four-fifths of a cylinder. 

Inferior Maxilla. — (PL XIII. 2-4.) Of the two fragments of the lower jaw pre- 
served in Dr. Owen's collection, which are both of the left side of two different 
adult individuals, the one contains the last two molars and half of that in advance, 
and the other contains the third to the fifth inclusive. The depth of the lower 
jaw below the posterior molar is twenty-eight lines, and its thickness fourteen lines. 

Superior Molars. — (PL XII.) The superior molars are about three-fourths the 
size of those of Rhinoceras indicus, and present a very great degree of resemblance 
to those of Aceratherium incisivum. All jiossess a basal cingulum, which, howevei", 
is feebly developed at the outer side of the antero-external lobe, and is entirely 
obsolete at the base postero-internall}^ of the fifth and sixth molars, and for a nar- 
row space internally . upon the antero-internal lobes of the same pair of teeth. 
Upon the inner side of the base of the molars, from the second to the fourth in- 
clusive, it is better developed than in the same position in Aceratherimn incisimim. 

In the seventh molar, the lobes are quite simple, neither of those within sending 
any sublobes into the single valley of the tooth, although they are very feebly 
bulging about the middle of their course. 

In the corresponding lobes of the two molars in advance, the bulging of that 
anterior successively increases, while that posterior in the same position is con- 
stricted. This bulging of the lobes diminishes the depth of the principal valleys to 
a degree corresponding to its successive increase forward. 



RHINOCEROS. 85 

The bottom of the single, simple valley of the last molar is nearly level its 
whole length, and is bounded at its entrance by a prominent portion of the basal 
cingulum. 

The principal valleys of the sixth and fifth molars are successively shallower 
externally, and deepen in a sloping manner toward their entrance, where they are 
partially closed by a prominent portion of the basal ridge, and hence, in the tritu- 
ration to which the teeth are subjected, these valleys are obliterated from without 
inward, and leave no isolated enamel islands, or pits, as in the molars in advance, 
or in the corresponding teeth of Rhinoceros indicus. 

In the sixth molar, the posterior valley is as deep externally as the principal 
valley, and in the fifth molar it is deeper. 

In the specimen under consideration, trituration has left the principal valley of 
the fifth molar as a tract of enamel, which is narrow and slightly depressed ex- 
ternally and curves backward and inward, and expands and deepens as it approaches 
its termination. 

In the second to the fourth molar inclusive, the inner lobes at their bases in- 
ternally are confluent, and from the degree of trituration which the third and fourth 
molars have undergone in the specimen, the principal valleys are left as simple, 
oblique, trilateral pits or islets of enamel, occupying . the centre of the exposed 
dentinal surface. In the second molar, from the less degree of confluence of the 
inner lobes internally, in addition to its being less worn, the principal valley still 
remains open. 

In the fourth molar, the postero-internal lobe is not much more than half the 
thickness of that in advance ; but in the second and third molars, the inner lobes 
are nearly equal in size. 

The basal cingulum of the molars, from the second to the fourth inclusive, en- 
velops the base of the postero-internal lobes to a much greater extent than upon 
the antero-internal lobes, or rather these are shorter than the former, and the basal 
ridge descends in its course postero-in tern ally, where it is very thick and strong, 
and is so prominent, that when the teeth are worn down so that the principal val- 
leys remain only at their outer extremity as very small pits, the posterior valleys, 
which are very nearly as deep, would be left in the same condition. 

The first molar in the specimen presents an almost equi-trilateral surface of ex- 
posed dentine, with the internal lobes of the crown curving inward and backward 
and dilating at their termination, and with the antero-external lobe forming its 
anterior rounded and prominent apex. Portions of a basal ridge connect the 
bases of the inner and the antero-external lobes together. The short principal 
valley remains as a narrow tract of enamel constricted at the middle and deepened 
at both extremities. The posterior valley remains as a small trilateral islet of 
enamel. Between the antero-external and internal lobes the basal ridge forms a 
broad cul-de-sac. 

Inferior Molars. — (PI. XIII. 2-6.) The teeth, preserved in the fragments of lower 

jaws referred to, belong all to the posterior four molars, and these do not differ in 

their form from those corresponding to them in recent species of Rhinoceros. A 

basal ridge with a rough margin exists in all, but is obsolete on the inner side of the 

12 



86 



KHTNOCEROS. 



posterior tliree molars, and on the outer side of the posterior lobe of the same teeth, 
except the last. Between the bases of the lobes externally it forms a small 
tubercle. 

Other Teeth. — No incisors are preserved in any of the specimens, but from a 
portion of alveolus preserved in one of the latter, already referred to, it is of course 
conclusive that incisors existed in the adult, at least in the upper jaw. 



MEASUREMENTS OF TUE HEAD AND TEETH. 

Length of skull from the upper margin of the occipital foramen to the inter- 
maxillary bone ......... 

Length of skull from same position to the first molar 
Breadth of inion at the mastoid processes; estimated 
Greatest breadth at the zygomata ...... 

From the tip of one post-glenoid tubercle to the other; estimated . 

Distance from the meatus auditorius externus to the lachrymal tubercle 

Height of face from alveolar margin on a line with the anterior orbital margin 

Height of face from alveolar margin on a line with the infra-orbitar foramen 

Greatest breadth of forehead at the supra-orbitar processes 

Length of upper molar series 

Greatest breadth of seventh molar 

Greatest breadth of sixth molar . 

Greatest breadth of fifth molar 

Greatest breadth of fourth molar 

Greatest lireadth of third molar . 

Greatest breadth of second molar 

Greatest breadth of first molar 

Antero-posterior diameter of last lower molar 

Antero-posterior diameter of the third lower molar 



Lines. Inches. 



16 


9 


15 


4 


5 





8 





3 


6 


8 





5 


6 




6 









3 




7 




8 




7 




6 




4 









9 




6 




1 



Rhinoceros IVebrascensis, Leidy. 

(Plate XIV., XV.) 

HJiinoceros Nebrascensis, Leidy: Proc. Acad. Nat. Sci., 1850, v., 121; Owen's Rep. of a Gool. Surv. of 
Wise, etc., 556. 

Aceratherium Nebrascensis, Leidy : Proc. Acad. Nat. Sci., 1851, v., 331. 

Of the smaller Rhinoceros of Nebraska we possess portions of at least twelve 
different individuals, as follows : — 

1. The anterior portion of a skull, accompanied by the lower jaw, of an adult 
individual. The former has the forehead, orbital entrance, and molar teeth well 
preserved, but the face is very much broken, and its nasal part is displaced. The 
lower jaw contains all the molars in perfect condition, but it has lost its rami and 
the symphysis. (XIV. 1-3.) From Captain Stewart Van Vliet's collection. 

2. A much mutilated face, containing on both sides the molar teeth nearly per- 
fect. It belonged to a nearly adult individual, as the teeth, Avhich belong to the 
permanent series, are all in place except the last, which has about two-thirds 
protruded. (XIV. 13.) From the collection of Dr. Owen. 

3. The skull, accompanied by a small fragment of the lower jaw, of a very old 
individual. The former has its upper part broken away, but the base is nearly 



RHINOCEROS. 87 

entire ; and it contains all the molar teeth, which have their crowns worn nearly 
to a level with the alveolar margin. (XV. 1, 2.) From Dr. Owen's collection. 

4. The crowns of four permanent premolars of the left side of the upper jaw 
and one of the right side. These are perfect and are not at all worn, having been 
concealed within the maxillary bones, from which they were removed with much 
labor. (XIV. 4-8.) Presented to the Academy of Natural Sciences, by Mr. 
Alexander Culbertson. 

5. A small fragment of an upper jaw containing the first permanent true molar, 
slightly worn, and a portion of the fourth permanent premolar, which was still 
concealed within the bone. From Dr. Owen's collection. 

G. A small fragment of an upper jaw, with an unworn sixth molai', and the 
seventh unprotruded. From Mr. Culbertson's collection. 

7. A second inferior permanent molar, and two fragments of lower jaws. One 
of the latter contains the fifth molar unworn, and the other contains a sixth molar 
partially protruded. All three specimens are apparently from different individuals. 
From Mr. Culbertson's collection. 

8. A fragment of the right side of a lower jaw, containing the last three molars. 
From Dr. Owen's collection. 

9. A fragment of the left side of a lower jaw of a very young animal, containing 
the last temporary molar unworn, and the first permanent true molar protruded. 
(XIV. 9, 10.) From Dr. Owen's collection. 

10. A fragment of the right side of the upper jaw, containing the posterior three 
temporary molars, which are considerably worn. (XIV. 14.) From Mr. Culbert- 
son's collection. 

Desci-'iption of the Head. — The skull of RJiinoceros Nehrascensis is about three- 
fourths the size of that of Rhinoceros occidenialis. 

Lateral View. — (PI. XIV. 1 ; XV. 1.) So far as can be ascertained from the im- 
perfect specimens, the side of the head presents most of the characters of that of 
Itlunoceros occidentalis. 

The root of the zygomatic process is implanted about the middle of the bottom 
of the temporal fossa, and its upper surface is antero-posteriorly convex. 

The temporal surface is convex and smooth, and, as in Rhinoceros occidentalis, 
apparently rose upon a prominent sagittal crest. Its occipital border curves from 
the base of the mastoid process upward and backward to the summit of the inion. 

The squamous portion of the temporal bone is nearly vertically convex, and is 
an inch in height above the root of the zygomatic process. 

The squamous suture at its ujiper part pursues a course almost horizontal for 
nearly three inches. At its posterior part, in the particular specimen under investi- 
gation, there are two deep, ascending, vascular grooves. 

The orbit has about the same form as in Rhinoceros occidentalis, but in the 
specimens its floor is more superficial. 

The optic foramen is large and vertically oval, and is placed an inch in advance 
of the spheno-orbital foramen. 

The margin of the orbital entrance is as well defined as in Rhinoceros occidentalis; 
but the supra-orbitar process is neither quite so prominent nor so rough. 



88 RHINOCEROS. 

The post-orbital process, though merely the termination of the supra-orbital 
margin, is nevertheless well marked compared with its condition in Rhinoceros 
indicus. 

As in the latter, there exists a prominent lachrymal process ; but there are two 
lachrymal foramina, placed one above the other internal to the process. 

The malar bone is robust, and in its course is directed a trifling degree more 
outward than in JRJiinoceros occidentaUs, and its external face presents more upward. 

The alveolar portion of the face is vertical, but antero-posteriorly is convex. 
The position of the lachrymal bone presents an oblique slightly depressed surface. 

The infra-orbital foramen is placed about an inch above the interval of the 
second and third molar teeth. 

In all the specimens, the remainder of the face is too much broken to form any 
correct idea of its form. 

Superior Vieic. — (PL XIV. 11.) The forehead, preserved nearly entire in one 
specimen, is broad, and above the orbits is elevated and convex, but is depressed 
towards the median line. The temporal ridges converging from the post-orbitar 
processes are relatively not so prominent as in Rhinoceros occidentaUs ; but, as in 
this, they evidently conjoin to form a sagittal crest. 

Posterior View. — (PI. XIV. 12.) The inion has a more trilateral outline than 
in Rhinoceros indicus, and in the middle it is much more bulging or prominent, so 
that the superior angular margin of the foramen magnum projects considerably 
posterior to the basilar margin. Towards the summit the median portion of the 
surface of the inion becomes depressed, and each side is directed quite laterally in 
its course to the temporal margin. 

The occipital condyles are more vertical in their relation to one another than in 
Rhinoceros indicus ; and above each there is a well-marked depression of the surface. 

The occipital foramen is subrotund, and about ten lines in diameter, and it has 
an angular margin above and a concave one below. It is directed backward and a 
little downward. 

Inferior Vieio. — (PI. XV. 2.) In the specimen in which the base of the skull is 
preserved, the junction of the basilar process and sphenoidal body is completely 
obliterated. Near its position on each side is a superficial rough elevation for 
muscular attachment. 

The median line of the basilar process is prominent, and each side is slightly 
depressed. 

The sphenoidal bodies are prominently convex, and within the roots of the 
pterygoid processes slope on each side to form a broad shallow groove for the 
Eustachian tube. 

Separated by the anterior scroll-like terminations of the occipital condyles, a 
distance of ten lines, are the anterior condyloid foramina, which are oval and three 
lines in diameter antero-posteriorly. 

To the outside of the latter, and a little in advance, is the para-mastoid process, 
existing in the specimen as a broad stump, compressed antero-posteriorly. 

The mastoid process forms the posterior abutment of a high arch conducting to 
the entrance of the tympanic cavity, or in other words the meatus auditorius, as it 



RHINOCEKOS. 89 

exists in Ehlnoceros indicus, is open at the bottom. The process is strong and is 
bent forward at its apex, wliich is tuberous and extends nearly as far downward as 
the post-glenoid tubercle, from which it is about live lines distant. 

The pars petrosa is quite small. It appears at the bottom of the arch between 
the post-glenoid and para-mastoid processes, as a V-shaped body, bent forward at 
its lower part by the base of the styloid process. 

The remaining portion of the latter, in the specimen, is a stout cylinder clasped 
antero-internally by the os petrosa. 

Between the bottom of the styloid and para-mastoid processes is the stylo- 
mastoid foramen. 

The foramen lacerum is a veiy large I'cniform vacuity, being about an inch in 
diameter antero-posteriorly, and about four lines transversely. 

In advance of the latter a few lines is a distinct foramen ovale, and a short 
distance antero-internal to this is a round foramen, conducting into the homologue 
of the foramina rotundum and spheno-orbitale. 

The latter opens at the bottom of the orbit just internal to a pointed process 
arising from the conjunction of three ridges; one of which comes from the margin 
of the foramen, the other from above the position of the optic foramen, and the 
third constitutes the boundary of origin between the temporal and external ptery- 
goid surfaces. 

The optic foramen is placed about an inch in advance of the spheno-orbitale. 

The glenoid articulation is more concave than in Rhinoceros indicus, and that 
portion of its surface situated on the anterior part of the root of the zygomatic 
process presents more backward and outward. 

The post-glenoid tubercle, compared with that oil Rhinoceros indicus, is relatively 
short ; at its outer margin being ten lines in length, and it projects only two lines 
below the mastoid process. What it loses in length it gains in robustness and 
breadth ; and its outer side is rough, and the apex truncated. Posteriorly it is 
perforated by a vertical foramen. 

The interpalatine notch extends forward as far as the posterior third of the 
penultimate molar tooth. 

The hard palate is strongly arched, though not so much as in Rhinoceros occi- 
dentalis, and it also differs from that of the latter in being relatively broader, and 
less convergent at the alveolar margin anteriorly. 

Inferior Maxilla. — (PI. XIV. 2.) The body of the lower jaw externally is ver- 
tically convex, and anteriorly is more convergent than in Rhinoceros indicus. Its 
depth below the posterior molar tooth is about twenty lines ; below the first molar, 
fifteen lines. The base is rounded, and is about as convex antero-posteriorly as in 
the last mentioned species. 

In the specimen under investigation, the symphysis is broken off a few lines in 
advance of the molars, and it there presents a crescentic surface only ten lines 
broad and six deep, indicating the inferior incisor teeth to be of small size in this 
species. Upon each side of the broken surface, about three-fourths of an inch from 
the position of the first molar teeth, there remains the end of the fang of the 
external incisors. 



90 RHINOCEROS. 

The anterior mental foramen occupies a position near the base of the bone below 
the hinder fang of the second molar of the remaining series. In advance of it, on 
nearly the same line, are two other and smaller foramina of the same kind. 

A portion of the ramus shows this to have been thin and deej)ly excavated 
internally, as in the Tapir. The posterior mental foramen is large, and placed 
about one inch behind the last molar tooth. 

Dentition. — Except the first inferior molar tooth, which is shed at an early 
period, the entire series of permanent molar teeth in Bhinoceros Nehrascensis is 
retained to a late period of life, as is indicated by the specimen of a skull of a 
very old individual in the collection of Dr. Owen, in which, although the crowns 
are almost completely worn away, yet the whole number remains. 

From minute fragments of fangs of an upper and lower incisor existing in two 
of the adult specimens under investigation, we are satisfied of the existence of 
these teeth permanently, but the number we have no means of ascertaining. 

Superior Molars. — (PI. XIV. 1, 13; XV. 3.) The upper molars bear a very gi'eat 
resemblance in form to those of Aceratherium incisivum ; and they possess a basal 
ridge all round except at the inner side of the bases of the internal lobes of the 
true molars, and where it has been obliterated by pressure from the teeth in contact. 

The outer surface of the true molars is broad and slightly depressed at the 
middle, and at the anterior fifth forms an abrupt fold, as in all other species of 
liJdnoceros. 

The last molar exhibits a disposition to the development of a posterior valley, 
or rather a separation, as in the other molars, of the postero-internal and external 
lobes. The anterior valley of this tooth is almost as deep as the crown, is nearly 
level at bottom, and is bounded at its entrance by a mammillary eminence, which 
is a portion of the basal ridge. The hinder lobe is quite simple, and exhibits no 
tendency to encroach upon the anterior valley ; but the antero-internal lobe at its 
middle posteriorly protrudes considerably into the latter. 

The inner lobes of the true molars in advance expand gradually to their base, 
are impressed anteriorly, and protrude into the valleys about their middle poste- 
riorly. The valleys are of equal depth at their outer extremities or termination, 
and the principal ones, except in the penultimate tooth in one specimen in which 
the bottom throughout is nearly uniform, deepen towards their entrance, so that in 
the trituration to which the teeth are subjected in mastication, as in Rhinoceros 
occidentalis and Aceratherium incisivum, they become obliterated from without in- 
wardly. The entrance of the anterior or principal valleys in the fifth and sixth 
molars is not obstructed by the existence of a constituent portion of the basal 
ridge, as in lihinoceros occidentalis. 

A small fragment of an upper jaw, presented to the Academy of Natural Sci- 
ences by Mr. Alexander Culbertson, contained the crowns of the four premolars 
entirely concealed within the bone. These, having been divested of their hard 
envelop, are remarkable for their state of preservation and beauty, and lead me 
to describe them more minutely than may be considered essential. (XIV. 4-8.) 

The first premolar is only three-fourths the size of the others, and it is trilateral 
with the inner and posterior sides, forming a continuous convexity. The posterior 



KHINOCEROS. 91 

three premolars increase slightly to the last one, and they are quadrate and have 
the inner side convex and narrowest. 

The outer side (4) of these teeth forms a large quadrilateral surface with rounded 
angles. It is slightly convex, and is feebly waved longitudinally. At the fore part 
a narrow fold descends from the base and expands towards the triturating margin; 
but it is successively less developed forward, and in the first of the series is rudi- 
mentary. This fold increases in depth in the true molars, and is quite character- 
istic of the outer part of these teeth in lildnoceros, as it does not exist in Palaeo- 
therium, Tltanotlierium , nor Anchitherium. 

In advance of the fold just described, the antero-external margin of the molars 
projects forward and slightly outward, and looks like an independent column or 
buttress, and is the shortest portion of the outer lobes. 

The triturating margin of the latter, in the specimens of premolars under especial 
examination, is bilobed and acute. 

The inner surface of the postero-external lobe is a little convex, and from the 
same surface of the antero-external lobe in the third and fourth premolars an abrupt 
fold projects into the principal valley of the teeth (5). This fold, when the teeth 
are partially -worn away, gives the termination of the principal valley a bifurcated 
appearance; and in Rhinoceros indicus and Rhinoceros tichorinus it is the extension 
and confluence of the fold with the anterior part of the postero-internal lobe of the 
teeth which produces a division of the principal valley, represented when the teeth 
are considerably worn away by two enamel pits. 

The internal lobes have acute summits and more or less expanding bases, and, 
except in the first tooth, their inner extremities for more than half their depth are 
confluent, so that the principal valley is a deep pit, with shelving sides and an 
internal notch (5, 6). 

In the fourth premolar, the postero-internal lobe is a sigmoid fold projecting from 
the confluence of the outer lobes. 

In the three premolars in advance, the postero-internal lobe consists of two 
portions; an inner pyramid with two broad sides directed obliquely antcro-poste- 
riorly, and a bent fold extended between the confluence of the outer lobes and the 
outer side of the pyramid, and separating the two characteristic valleys of the 
teeth. This fold does not reach the summit of the inner pyramid, nor of the outer 
lobes, and it looks more like a narrow partition separating the valleys than a 
constituent portion of the postero-internal lobes. 

The antero-internal lobe of the premolars, except in the first, is directed trans- 
versely inward on a line with the characteristic fold of the outer surface of the 
teeth, and it expands as it approaches its termination, and antero-internally swells 
into a sort of conoidal buttress, gradually increasing in distinctness from the second 
to the last premolar. In the first premolar it appears only as a small, compressed 
mammillary eminence of the basal cingulum. 

The latter, as in Rhinoceros occidentuJis, is well develoj^ed ujdou all the premolars. 
In the specimens under special examination, ossification had not yet advanced to 
its production, externally (4), but in older specimens in this position it measures 
over a line in depth (1). At the postero-external margin of the teeth it very 



92 RHINOCEROS. 

abruptly descends half the length of the crown (6), then, proceeding inward, it 
envelops the base of the postero-internal lobe, and internally it ascends to the base 
of the antero-interual lobe, and winds anteriorly to the antero-external margin of 
the crown, and then makes an abrupt ascent to the base externally (7, 8). 

The anterior and posterior valleys in all the premolars are deep culs-de-sac with 
shelving sides (5). 

When the molar teeth have had one-half their crown worn away in mastication 
they are hardly recognizable in those which have not been subjected to trituration. 
Comparatively with one another, they of course suffer attrition most in the order of 
their succession, and this, judging from the specimen in Dr. Owen's collection, in 
which the seventh molar is only partially protruded, may be determined to occur 
in the following manner. After the temporary teeth, the fifth molar is protruded, 
and in the permanent series appears most worn; then succeed the first to the fourth 
permanent molars, then the sixth, and finally the seventh (13). 

In the specimen of the skull containing all the molars, jjresented by Capt. S. Van 
Vliet to the Smithsonian Institution, these teeth are worn about one-half awa}', and 
exhibit very strikingly the transformation of form produced by attrition. (KV. 3.) 
The enamelled grinding surface of the fifth molar, except a short inlet consti- 
tuting the entrance of what was the principal valley, has been completely oblite- 
rated. The exposed dentinal surface is concave, and bordered by enamel, except 
anteriorly and posteriorly, where it also appears to have been removed, probably 
from the combined influence of long-continued pressure and friction from the 
contiguous teeth. 

In the sixth molar, the exposed dentinal surface is more deeply bilobed internally 
than in the former; or, in other words, a longer tract of enamel remains from the 
anterior valley; and farther, almost the whole of the bottom of the posterior valley 
yet remains. 

The seventh molar, from its being the last to take its position in the functional 
series, is worn less than any of the others. Its valley remains entire, except that 
it is rendered a little more shallow, from the summits of the lobes which embrace 
it being worn off. The exposed dentinal surface presents an iri'egular V-shaped 
figure, with the apex and extremities of its arms bifurcated. 

The second to the fourth molars inclusive present nearly square dentinal surfaces 
bordered with enamel, bilobed internally, and possessing, each, two trilateral pits 
of enamel, the remains of the valleys. The central pit is the larger, and has 
convex sides and rounded angles; and the smaller pit is in contact with the poste- 
rior border of the teeth. 

The exposed dentinal surface of the first premolar, in the specimen, upon one 
side of the jaw, has two small circular pits of enamel, and on the other, a single 
trilateral pit, which remains from the posterior valley; and in both teeth a cul-de- 
sac in connection with the internal border exists before and behind the rudimentary 
antero-internal lobe. 

When the enamelled triturating surfaces of the molars are completely obliterated 
by mastication (1, 2), as is the case in the specimen of a skull of a very old animal 
in the collection of Dr. Owen, the exposed dentinal surfaces are quadrate and bilobed 



RHINOCEROS. 93 

internally, a little broader transversely than antero-posteriorly, smooth and more 
or less depressed. Most of the crowns are bordered with enamel only at their 
internal portion; it having entirely disappeared upon the true molars externally, 
and probabl}^ also upon the premolars, but these, in the specimen, are too much 
broken at their outer part to judge. Between the teeth also the enamel has par- 
tially and in many positions entirely disappeared, so that the dentinal masticating 
surfaces are separated only by the interstices of the crowns. 

Inferior Molars. — (PL XIV. 2, 3.) The normal number of lower molar teeth of 
Rhinoceros is seven, as in the upper jaw; but in the only specimen of the lower jaw 
of Rhinoceros Nehrascensis which we possess, the number of molars on each side is 
six ; the first having been long shed and its alveolus entirely oljliterated. 

In form, the inferior molars resemble closely those of all other species of Rhinoceros. 
All have a basal ridge surrounding them, except whei'e it has been obliterated, in 
the course of time, by pressure and friction between the teeth. 

The second molar of the normal series, in outline transversely, presents an isos- 
celes triangle, but, like the others, it is constituted of two distinct lobes, of Avhich 
the anterior is so much compressed laterally as to lose the ci'escentoid form. 

In the specimen of the lower jaw accompaiij'ing the skull obtained by Captain 
Van Vliet, the crowns of the molars are considerably worn away. The fifth molar 
has its two crescents nearly obliterated; the sixth is less worn; and then follows in 
succession the fourth to the second, and then the seventh. In the latter, the exjsosed 
dentinal surfaces of the crescentic lobes are distinct, but in all the others they have 
become confluent. From the long continuance of pressure and friction the enamel 
has disappeared where the teeth are in contact, except between the anterior and 
the posterior two. 

In a small fragment of lower jaw accompanying the skull of a very old animal 
in Dr. Owen's collection, containing the fifth molar, the enamel of this has been 
worn away, except a very small portion at each posterior angle, and the masti- 
cating sui'face of dentine in outline has the form of the figure 8, and is trans- 
versely convex and antero-posteriorly concave. Small fragments of the teeth in 
advance and behind, in the same specimen, indicate them not to have been as much 
worn, so that the nearly entire tooth is probably the first of the true molar series. 

Temporary Molars. — The posterior three temporary molars, as I suppose them 
to be, contained in a fragment of the upper jaw, are of about the same size 
as their permanent successors (XIV. 14). They are more square, or are less 
contracted and convex internally, and the inner lobes are more equal in size, and 
do not become confluent internally. In consequence of the latter arrangement, the 
principal vallej's are open at their entrance to the bases of the lobes, and in the 
third and fourth molars they deepen from without inward, as in the case of the 
two anterior permanent true molars. In these two temporary teeth, also, the poste- 
rior valleys are deeper at their outer end than those anterior. In the second molai-, 
the bottoms of both valleys are nearly uniform in their depth throughout and with 
each other. The basal ridge is horizontal upon the inner side of the temporary 
molars, and in front and behind very gradually descends to the external margins 
of the crown. 
13 



94 



RHINOCEROS. 



The inferior last temporary molar preserved unworn, in company with the first 
permanent true molar protruded, in a fragment of lower jaw, exhibits a disposition 
to the formation of three lobes, by the ordinary anterior normal lobe being deeply 
notched at its anterior horn, while in advance of this a smaller transverse lobe, 
slightly bent forward and inward, is developed at its outer side. A continuous 
basal ridge surrounds the tooth, which otherwise than in the characters given 
corresponds with the permanent molars. (XIV. 9, 10.) 



MEASUREMENTS OF THE HEAD AND TEETH. 

Length of skull from the upper margin of the occipital foramen to the anterior 

part of the first molar tooth 
Breadth of inion at ends of mastoid processes 
Greatest breadth at the zygomata (estimated) 
Breadth at the post-glenoid tubercles . 
Distance from meatus auditorius to the lachrymal tubercle 
Height of face from the alveolar margin on a line with the middle of the orbit 
Greatest breadth of forehead at the supra-orbitar processes 
Breadth of hard palate about its middle 
Length of upper molar series 
Length of lower molar series 
Breadth of last superior molar 
Breadth of fourth molar 
Breadth of first molar 

Antero-posterior diameter of fifth upper molar 
Antero-posterior diameter of second upper molar 
Antero-posterior diameter of first upper molar 
Antero-posterior diameter of last lower molar 
Antero-posterior diameter of first (of six) 
Breadth of fourth lower molar 



Inches. Lines. 



9 





3 





5 


2 


3 


4 


4 


G 


3 


4 


3 


5 


1 


7 


4 


10 


4 


4 





11 





11 





6 





11 





8J 





6J 





11 





Ik 





6i 



CHAPTER III. 

CAIINIVORA. 

Fam. — DiGITIGRADA. 
GcH. ITIACHAIRODIJS, Kaup. 

The genus Machairodus was proposed by Kaup upon specimens of upper canine 
teeth, found in the later tertiary deposits of Europe, remarkable for their length, 
falciform shape, and serrulated margins. They had been previously referred to 
the genus Ursus, but the discovery in France, by M. Bravard, of an almost entire 
skull containing a tooth like those in question, decided the animal to belong to the 
feline family. 

Several species occurring in Europe and India have since been indicated, and 
the skull of a very large one was discovered by M. Lund in the caverns of Brazil. 



ITIacliairodii!^ iiriiuaevus, Leidy and Owen. 

(Plate XVIII.) 

Machairodus primaemis, Leidy and Owen: Proc. Acad. Nat. Soi., 1851, v. 329; Owen's Rep. of a Geol. Surv. of 
Wise, etc., 564. 

Among the mammalian remains brought by Dr. Evans, while engaged in the 
geological survey of Dr. Owen, from the Mauvaises Terres of Nebraska, is the head 
of a small species of Machairodus, which is probably the most ancient known. 

The species was characterized in the Proceedings of the Academy of Natural 
Sciences under the name of Machairodus primaemis. 

The specimen upon which the latter is established is very much fractured and 
fissured, and it has the summit of the inion, the zygomata, anterior extremities of 
the ossa nasi, superior incisors, and the greater portion of the corresponding canines, 
and the symphysis of the lower jaw with the incisors and canines, broken away. 
"When first received, it was partially enveloped in a matrix, which, though having 
the same general appearance as that inclosing all the other mammalian fossils from 
Nebraska, was unusually hard. Attached to the mass, but separated from the 
skull, was the greater portion of a tooth, which I have considered to be of an 
inferior canine of the same animal; but it may be one of the upper incisors, which, 
as indicated by the alveoli, are relatively very large compared with the correspond- 
ing teeth of Felis. 



96 MACHAIRODUS. 

The head of this species is about half the size of that of Machairodus Jicogaus, 
and indicates an animal about one-fifth smaller than the American Panther, Fells 
concolor. 

Lateral Vieio. — (PL XVIII. 1.) In the side view, the upper outline of the skull 
is more convex antero-posteriorly than in the species of Machairodus just mentioned 
or the Panther, from the greater elevation of the forehead above the orbits posteriorly. 
The ossa nasi are not prominent above the border of the upper extremity of the 
OS maxillare superius, as in Felis, but are concealed from view laterally, and the 
anterior slope of the head is more uniform in its descent, or is less arched than in 
this genus. 

The temporal fossa relatively to that of Felis is shorter, of greater breadth, and 
much greater depth. The anterior surface of the zj-gomatic root inclines at an 
angle of about 50°, instead of being nearly horizontal, as in Felis. The temporal 
surfiice generally disposes to be much more rapidly convergent towards its exit 
inferiorly than in the latter, and indeed the whole arrangement of the temporal 
fossa is such as to have given a much less oblique course to the fibres of the 
temporal muscle. 

The entrance to the meatus auditorius is not a broad archway, as in Felis, but is 
a relatively deep nari'ow arch, apparently resulting from a modification of that in 
the latter genus, produced Ijy the root of the zygomatic process being depressed 
downward and backward. The meatus is bounded posteriorly by a relatively very 
robust and distinct mastoid process, which is directed downward and forward, and 
has a broad rough apex for muscular attachment. The posterior surface of the 
process curves upward and backward, and its base abuts against the paramastoid 
jDrocess, which is a short, thick, roughened tuberosity. 

The form, relative size, and direction of the orbit are the same as in Fdis ; being 
ovoid, with the narrower part above. It is an inch and four lines in vertical 
diameter, and has the plane of its entrance inclined at an angle of about 50°; 
presenting outward, fcirward, and upward. 

The infra-orbitar foramen is vertically oval, and not only relatively but absolutely 
very much larger than that of the Panther. It is about half an inch in vertical 
diameter and five lines transversely, and is situated internal to the position of the 
orbit, with more than half its extent placed above the line of the lower margin of 
the latter. 

Above the foramen, just in advance of the orbital margin, the surface is more 
definitely concave than in Fdis, and anterior again to this the convexity of the 
canine alveolus commences. 

In the specimen, the upper carnassial tooth is placed fiir external to the tooth in 
advance, but this relation of position ajjpears to be the result of a dislocation inward 
of the latter, and it is most probable that in the natural condition the upper molars 
were arranged in an oblique line convergent forward and upward, as in Felis. 

The anterior portion of the external alveolar surface is transversely concave, but 

vertically is very strongly convex in comparison with what it is in the latter genus. 

Superior View. — (XVIII. 2.) In the upper view of the skull, the temporal 

surfaces above the position of the roots of the zygomatic processes are much less 



MACHAIIIODUS. 97 

convex than in Fells, and just bcliind the post-orbital processes are more deeply 
excavated and of much greater vertical extent. 

The sagittal ci'est, though broken in the specimen, can yet be seen to have been 
prominently elevated and strong to the point of its bifurcation. 

The forehead is much more strongly arched than in Fdi^i, and also is more 
depressed along its median line. 

The coronal and squamous sutures ai'e entirely co-ossified in the specimen, and 
the frontal suture is also obliterated, but its original position is indicated by a 
rugged line. 

The ftice is relatively much broader superiorly than in FeJis, and along the sides 
of the ossa nasi it is rendered prominently convex by the greater degree of exten- 
sion, upward and backward, of the canine alveoli than in the latter genus. 

The posterior portions of the ossa nasi, remaining in the specimen, are relatively 
narrow comjjared to those of the Panther, are placed slightly below the general 
level of the corresponding part of the forehead and face, and are quite flat and 
slightly inclined towards each other. 

The intermaxillaries are not quite so prominent forward as in Fells, but they are 
rather stronger, in accordance with the greater size of the incisive teeth. 

The inion, which at its upper part is broken, appears to have had nearlj^ the 
same form as in Felis; but the short thick paramastoids are situated higher, and 
the fossaj between them and the occipital condyles are less deep. 

The latter and the occipital foramen have the same form and relative size and 
position to each other as in Fells. The foramen is transversely oval, nine lines in 
its greater, and six and a half lines in its shorter diameter. 

The base of the skull, for the most part, is enveloped in a hard matrix, which 
to remove would endanger the integrity of the much fissured specimen; neverthe- 
less it presents a few points visible and worthy of notice. 

The mastoid processes are a little more advanced in their position, and more 
internally situated than in Fells. 

The anterior condyloid foramina are more exposed in their position than in Felis, 
or rather they are not directed to the same extent into the exit of the jugular 
canal. 

The auditory bullae though broken away in the specimen from their remaining 
connections, may be inferred to have been as well developed as in Felis. 

Inferior Maxilla. — (PI. XVIII. 1, 3.) The lower jaw corresponds in its general 
form with that of the latter, but it presents the same remarkable characters as in 
the other known species of Machairodus. 

The coronoid process is relatively very short compared with that of Felis, and, 
instead of curving backward, its posterior border is quite vertical to the base of the 
bone. 

The extent of the fossa below the coronoid process, and the form of the condyle, 
are about the same as in Felis. 

The post-coronoid process is short and thick, and is bent outward instead of 
inward, as in Felis. 

The external surface of the lower jaw, near the base and below the position of 



98 MACHAIEODUS. 

the first premolar, presents the commencement of a riclge, which no doubt passed 
to an alaiy process of the symphysis, such as exists in MacJiairodus neoyaus and 
other species. 

Nine Hnes of the hiatus in advance of the molars exists in the specimen, without 
any disposition anteriorly to expand for the accommodation of the canine alveolus. 
Its margin is acute, and, viewed from the broken part, appears a little everted. 
Below it externally the surface slopes in a slightly convex manner outwardly to 
the base of the bone, and it presents two small mental foramina. 

Dentition. — (PI. XVIII. 1, 3, 4, 5.) The upper jaw in the specimen contains the 
incisive alveoli filled with matrix, portions of the canines, the alveolus for the first 
molar, and all the other molars except the posterior two of the left side. The 
lower jaw contains only the molars. 

Characteristic of Maclicdrodus, the superior incisive alveoli indicate the possession 
of larger incisors than exist in Fells. Laterally they border so closely on the 
canine alveolus that a smaller hiatus is left than in other species of the genus, and 
they increase in size from the first to the last. 

The upper canine (1) is latei-ally compressed, and is relatively much less broad 
than in Machairodus neogaus, and was about half as long and broad as that of 
Machairodus cidtridens. In the fragment, pi-eserved in the specimen, the posterior 
sub-trenchant edge, about ten lines below the enamel border of the crown, com- 
mences to be crenulate, as in other species of Machairodus. Antero-internally thei'e 
exist the remaining three lines of a ridge, which commences near the enamel 
border and proceeds downward and forward, and at its lower third is also crenu- 
lated. In section the upper canine is elliptical, and is acute posteriorly, and at the 
enamel border of its crown measures seven lines and a half in breadth, and about 
four lines and a half transvei'sely. 

The first superior molar, as indicated by the remaining alveolus, had a simple 
mammilloid crown, as in Felis. The alveolus is subrotund, about one "and a half 
lines in diameter, and borders closely upon that for the canine. 

Posterior to the first molar, a relatively very large hiatus exists compared with 
that of Felis and other species of Machairodus, being four lines in length, or equal 
to the whole interval between the canine and second molar of Machairodus neogaus. 

The crown of the last mentioned tooth (3), compared with that of the Panther, 
is shorter relatively to its breadth, and in comparison of size with that of the 
carnassial tooth is relatively very much smaller than in any species of Felis. Its 
outer surface has the same inclination and prominent base as in the latter, but is 
less convex. It is composed of a median compressed mammillary cusp, with a 
trenchant margin, a small anterior lobe, as in Machairodus neogaus, and a posterior, 
simple, compressed mammillary lobe with a trenchant border, relatively equal to 
the corresponding pair in the latter species and in Felis. 

The crown of the upper carnassial tooth (1) has about the same relative size as 
in the latter genus, and also the same degree of inclination of its outer surface, 
but it does not possess the lenticular fossa at the conjunction of the median cusp 
with the posterior lobe. The anterior lobe descends much lower than in Fells, so 
as to shorten very considerably the corresponding margin of the median cusp. 



MACHxVIRODUS. 



99 



which in this position is more vertical and posteriorly is more oblique. The poste- 
rior lobe is broad as in Fells, but is less oblique at the trenchant margin, which 
also is indented as in the latter genus. 

The crown of the tubercular molar (1) is transversely oblong, as in the Domestic 
Cat, is three lines broad by two antero-posteriorly, and externally forms a mammil- 
lary tubercle, and posteriorly a smaller one. 

As previou.sly mentioned, the symphysis of the lower jaw, witli the incisors and 
canines, is broken away from the specimen. 

The portion of tooth supposed to be part of an inferior canine (4, 5) is of the 
right side. It corresponds in its form and relative size with that of Machairodus 
neogaits ; having a curved demi-conoidal crown, with the postero-internal side defined 
by longitudinal ridges, of which that external is most salient. At the enamel 
border this tooth measures three lines antero-posteriorly and two transversely. 

The first inferior molar (3) is relatively very much smaller than in Fells, and in 
form it is like that o^ Machairodus cidtridens ; the crown being compressed conoidal, 
with a small simple basal lobe anteriorly and posteriorly. 

The second molar (3) is less robust in its proportions than in Fells, and has the 
same form nearly, very much increased in size, of the first tooth ; for the posterior 
lobe, though broken in the specimen, appears to be quite simple, or it is without 
the prominent heel existing in the latter genus, and the division possessed by 
Madia Irodus neogaus. 

The inferior carnassial tooth (3) is quite peculiarly modified from the feline 
type, and if it had been found as an isolated and unique specimen, it would cer- 
tainly have led to the separation of the species from the genus llachalrodus. 
It possesses the two characteristic lobes, separated by a lai'ge angular notch with 
trenchant margins, as in Fells, but the slight posterior heel of this genus is developed 
into a broader lobe than that occupying a similar position in the tooth in advance. 
This third lobe is more than half the length of the crown, is depressed externally 
and notched at its upper posterior angle. It exists only in a rudimentary condi- 
tion in Machairodus neogaus. 



MEASUREMENTS. 

Length from occipital condyles to upper incisive alveoli 

Length from occipital condyles to lachrymal tubercle 

Height from base of lower jaw to forehead .... 

Breadth of cranium at most prominent part of temporal fossiie 

Breadth of forehead at po.st-orbitar processes 

Breadth at ossa mala) below their orbitar processes 

Breadth of face from inner side of infra-orbitar foramina 

Breadth at most prominent part of the canine alveoli 

Height of coronoid process from base of lower jaw 

Height of latter below first molar . . . ... 

Antero-posterior diameter of second upper molar . 
Antero-posterior diameter of upper carnassial tooth 
Antero-posterior diameter of first lower molar 
Antero-posterior diameter of second lower molar . 
Antero-posterior diameter of lower carnassial tooth 



luches. 


Lines 


. G 


5 


. 4 


4J 


. 3 


10 


. 1 


10 





8 


. 4 


4 


. 1 


9 


2 


1 


. 1 


7 


. 


11 


. 


51 


. 


10 


. 


3 


. 








8i 



C H E L N I A 



CHAPTER I. 



TESTUDO, Linnaeus. 

All the fossil turtles from Nebraska, which have come under my inspection, 
belong to the genus Testudo. 

In the ordinary constitution of Testudo, the osseous carapace is composed of ten 
vertebral plates, eight pairs of costal plates, and eleven marginal plates upon each 
side of a symmetrical nuchal and pygal plate. 

Fig. 1. 



1ms, 



Fig. 1. Ideal view of the structure of 
the carapace of Testudo. The dark out- 
lines indicate the boundaries of the scutes; 
the serrated lines, the limits of the plates. 
Ivp — lOvp (median line), vertebral plates; 
lep — Sep {i-ifjlit /(o)!f?), costal plates; Imp 
— limp, marginal plates; np, nuchal plate; 
PPi Pyg^l plate; Ivs — 5vs, vertebral scutes; 
Ics — 5 (Jt]ft), costal scutes; 1ms — 11ms, 
marginal scutes; ns,'nuchal scute; ps, py- 
gal scute. 




The first vertebral plate is oblong quadrilateral; the succeeding plates, to the 

eighth inclusive, are most usually hexahedral; the penultimate plate is inverted V 
14 



102 



TESTUDO. 



shaped; and the last of the series is rhomboidal, and is included in the notch of the 
latter and one similar of the pygal plate. 

The costal plates are alternately broader and narrower. 

In the recent condition, the carapace is invested by corneous scutes, which impress 
it with their form. 

There are five vertebral scutes, four pairs of costal scutes, and eleven marginal 
scutes upon each side of a narrow symmetrical nuchal scute and a broad undivided 
pygal scute. 

The plastron or sternum of Testudo is composed of a single, more or less i)yri- 
form, entosternal plate, inclosed by a pair of episternal and hyosternal plates, and 
posterior to the latter of a pair of hyposternal and xiphisternal plates. 



Fig. 2. 



Iras 




Fig. 2. Ideal view of tbe structure of 
the sternum of Testudo. en, entosternal 
plate; ep, episternal plate; hyo, hyosternal 
plate ; hyp, hyposternal plate ; xi, xiphi- 
sternal plate ; gu, gular scute ; pe, pectoral 
scute ; hu, humeral scute ; ab, abdominal 
scute; fe, femoral scute; ca, caudal scute; 
Imp — limp Qright), marginal plates of the 
carapace; 1ms — 11ms (^cy?), marginal scutes 
of the carapace ; ns, nuchal scute ; ps, py- 
gal scute; 9, lOvp, vertebral plates; pp, 
pygal plate. 



llms 



The corneous scutes of the sternum, which impress their osseous basis, consist of 
eight pairs, as follows: the gular, pectoral, humeral, axillary, abdominal, femoral, 
inguinal, and caudal scutes. 

Dr. Evans, in the Geological Report of Dr. Owen, before quoted, states that fossil 
turtles were found in a portion of the Bad Lands, some five or six miles in extent, 
having much the appearance of an ancient lake, where it is entered from Bear 
Creek, a tributary of the Cheyenne. At one of these lake-like expansions hundreds 
of fossil turtles were discovered. They do not rest immediately on the grassy plain 
that forms the present floor or bottom, but on the talus and debris, collected into 



TESTUDO. 103 

mounds, which have been derh'ed from the disintegration of the marly earths that 
have slid from above. The particular stratum in which they seem to have been 
originally imbedded, is a pale Uesh-colored, indurated, siliceous, marly limestone, 
situated from thirty to forty feet above, as shown in Number 7 of the geological 
section, page 13 of this memoir. In the succeeding pages I shall describe five 
species of Tesiudo, but at the same time I suspect that they may not all Ije truly 
distinct. 



Testiido ]Vebra$ceusis, Leidy. 

(Plate XIX.) 

Stjjlemys Nehrascensis, Leidy: Proc. Acad. Nat. Sci., 1851, v., 172. 

Tesiudo Nebrasceiisis, Leidy: Proc. Acad. Nat. Sci., 1852, vi., 59; Owen's Rep. of a Geol. Surv. of Wise, 
etc., 567. 

Of this species I have the opportunity^ of examining four specimens from the 
collections of Messrs. Culbertson, Captain Van Vliet, and Dr. Owen. All are more 
or less broken, and two are crushed; all have lost the anterior and posterior mar- 
ginal plates, and in one the carapace is almost entirely gone. They vary a little 
in size, and apparently belonged to immature individuals, as the costal plates had 
not yet been connected to the marginal plates by cartilage. 

The form of the species approaches very much that of the genus Emijs, and is 
more depressed than the Gopher, Testudo polyplievius. 

The marginal plates are oblique at the sides of the carapace, and turn abruptly 
beneath at their lower third. 

The processes of the sternum, which act as columns of support to the carapace, 
at the bottom of the lateral notches are remarkable for their prominence and thick- 
ness. Those anterior are twenty-one lines long, four lines broad, and two and a 
half lines thick, and ascend inwardly at an angle of about 45°, and are received at 
their free extremity into a pit about the middle of the outer margin of the first 
costal plate. Those posterior are equally strong with the former, and join the 
carapace at the junction of the fifth and sixth costal plates. 

The sternum is flat, turned a little upward anteriorly, and is slightly convex at 
its junction with the carapace. 

The axillary and inguinal notches are directed downward; and the line of union 
of the sternal with the marginal scutes is nearly parallel on the two sides. 

The species is the smallest and most depressed of those brought from Nebraska, 
and in all the specimens the arrangement of the plates is the same, except in the 
smallest, which has an additional vertebral plate introduced between the ordinary 
eighth and the inverted V-shaped penultimate plate. 

Plates of the Carapace. — (PI. XIX. Fig. 1.) The first vertebral plate has convex 
sides, and in the smallest specimen, being the only one in which it is preserved, is 
ten lines long and six broad. The vertebral plates, from the second to the eighth 
inclusive, are hexahedral; and to the fifth are nearly equal in size, but afterwards 
undergo a rather sudden reduction, and then also continue to be nearly equal. 

The second vertebral plate articulates with the first and second pairs of costal 



104 TESTUDO. 

plates; the tliird with the second and third; and in the same manner the remaining 
vertebral plates, to the eighth inclusive, articulate each with two pairs of costal 
plates. 

The first costal plate joins the first to the third marginal plate inclusive. 

Plates of the Plastron. — (PL XIX. Fig. 3.) In the largest specimen of Testudo 
Nehrascensis, in which the sternum is best preserved, the entosternal plate is pyri- 
form, and measures one and a half inches long by sixteen lines broad. It encroaches 
for a third of an inch upon the position of the gular scutes, and extends within a 
line of the humeral scutes. In the other specimens, the entosternal plate reaches 
the boundary of the latter. 

In the largest specimen, the episternal plates are one and a half inch long. 

The hyosternal plates are two and a quarter inches long, and in all the specimen.s 
articulate with the third to the fifth marginal plates inclusive. 

The hyposternal plates, in the smallest specimen, are one and a half inch long, 
in the largest two inches; and they articulate with the postero-inferior angle of the 
fifth marginal plates, and the sixth and seventh of the latter. 

Scutes of the Carapace. — (PL XIX. 1.) The vertebral scutes, from the second to 
the fourth inclusive, are hexahedral, and are broader than they are long. The 
second and third are nearly equal in size, and in the smallest specimen measure 
about nineteen lines broad by fifteen long. The fourth vertebral scute is sixteen 
lines bi'oad by fifteen long, and in another specimen, twenty broad by sixteen long, 
and it has the postero-lateral sides more convergent backward than in the pre- 
ceding scutes. 

Scutes of the Plastron. — (PL XIX. 3.) Upon the sternum, in all the specimens, 
the scutes agree in the details of their arrangement, except that in the smallest the 
anterior margin of the humeral scutes courses along the bottom of the axillary 
notches, but in the others turns forward and outward to the latter. 

The glilar scutes, the position of which is preserved in the largest sjaecimen, are 
one inch in length and are angular posteriorly. 

The j)ectoral scutes are two inches and one line long. 

The humeral scutes internally measure a half an inch in length, but externally 
expand before and behind, and join the axillary and the fourth and fifth marginal 
scutes. In the smallest specimen they reach to the sixth marginal scutes, but in 
the largest one not within several lines. 

The abdominal scutes of the largest specimen are two inches two lines long, but 
are a fourth of an inch less in the smallest one, and in this they join the sixth and 
seventh marginal and the inguinal scutes, and in that several lines of the fifth 
marginal scutes in addition. 

The lines of junction of the scutes of the sternum with those of the carapace 
ai'e nearly parallel on the two sides, and are undulant and intersect the sutural 
connection of the contiguous plates. 

The axillary scute rests upon the hyosternal and third marginal plates between 
the humeral and fourth marginal scutes. 

The inguinal scute is supported upon the hyposternal plate, and in the largest 



TESTUDO. 105 

specimen upon the sixth and seventh marginal plates, but in the smallest upon the 
seventh only, between the abdominal and seventh marginal scutes. 

MEASUREMENTS. 

THREE SPECIMENS. 

Smallest. Medium. Largest. 
Estimated length of sternum ........ 7 in. 

Breadth of sternum at inferior border of marginal scutes ... 4} in. 4| in. Sj in. 

Length of transverse curve of the carapace from the level of the sternum 8J iu. 

Height from the level of the sternum . 3 in. 

Length of the lateral marginal plates . . . . . . . liin. 1| in. 

Height of latter from the level of the sternum . . . . . li iu. 



Tcsfiido heuiisphei'ica, Leidy. 

(Plates XX., XXIV. Fig. 3.) 

Emys hcmisplierica, Leidy : Proc. Acad. Nat. Sci., 1851, v., 173. 

Testudo licmisplierica, Leidy : Proc. Acad. Nat. Sci., 1852, vi., 59 ; Owen's Rep. of a Geol. Surv. of Wise, etc., 
570. 

This species originally was established upon a specimen consisting of the sternum 
with a small portion of the carapace attached, from the collection of Capt. Van Yliet. 

In Dr. Owen's collection, a ^nearly entire carapace and sternum of the same species 
are preserved. 

The carapace is relatively more convex and hemispheroid, or rather hemi-ovoid, 
than that of any of the other fossil turtles brought from Nebraska. 

The lateral marginal plates are vertical; the axillary notches are directed out- 
ward and downward; the inguinal notches present downward; and the sternum is 
quite flat, except that its anterior extremity inclines upward. 

In both specimens, the costal plates of the carapace had yet been unconnected by 
suture with the adjoining marginal plates. 

The species presents the ordinary or normal number and arrangement of verte- 
bral plates. 

Plates of the Carapace. — (PL XX. 1.) The first vertebral plate is one and a 
quarter inch long by three-fourths of an inch broad; the succeeding plates, to the 
eighth inclusive, are hexahedral; those to the sixth being nearly equal in size; and 
the tenth transversely rhomboidal plate is three-fourths of an inch long by one and 
a quarter broad. 

The first costal plate is three inches long by one and three-quarters broad, and 
articulates w4th the first and second and four-fifths of the third marginal plates. 

The nuchal plate comes in contact with the position of the first costal scute at 
the anterior angle of this, and here measures two and a half inches in breadth. 

The pygal plate is vertical, and measures one and a half inch broad. 

Plates of the Plastron. — (PI. XX. 2.) The sternum is truncated anteriorlj^, and 
at its posterior extremity is rounded and emarginate. 

The entosternal plate is broad, pyriform, and extends for half an inch upon the 
position of the gular scutes, reaches posteriorly the boundary of the humeral scutes, 
and is about two inches long and broad. 



106 



TESTUDO. 



The episternal plates in the median line are two inches in length. 

The hjosternal plates are two inches and eight lines long in the middle, and 
articulate with the third to the fifth marginal plates inclusive. 

The hyposternal plates are tAvo inches two lines long, and articulate with the 
sixth and seventh marginal plates. 

The xiphisternal plates are convex at their margin, and are notched inter- 
mediately. 

Scutes of the Carapace. — (PI. XX. 1.) The vertebral scutes, from the second to 
the fourth inclusive, are hexahedral or quadrate, with bow-shaped sides, and are 
nearly equal in size. The fifth vertebral scute is prolonged anteriorly, and measures 
two inches in length. 

The nuchal scute is three lines wide, and the pygal scute two and a quarter inches. 

The gular scutes together measure two inches in width, and encroach for half aia 
inch upon the ento-sternal plate. 

Scutes of the Plastron. — (PI. XX. 2.) The pectoral scutes are two and three- 
quarter inches long. 

The humeral scutes internally are two-thirds of an inch long, and externally at 
their anterior border curve forward and outward to the axillte, and at their posterior 
border diverge backward and outward in a straight line, so as to join the axillary 
scute, half of the fourth and the whole of the fifth marginal scutes. 

The abdominal scutes are two inches and ten lines long, and join the sixth and 
seventh marginal scutes and the inguinal scute. 

The femoral and caudal scutes, in the median line, measure about one inch and 
two-thii'ds long. 



MEASUREMENTS. 



Length of the sternum ..... 
Breadth of the sternum ..... 
Length of the antero-posterior curve of the carajiace 
Height of the carapace from the level of the steruum 
Length of the lateral marginal plates 
Height of latter above the level of the sternum 



luches. 

Si 

6J 
12 J 

5 

2i 

3 



Testndo Ovreiii, Leidt. 

(Pl. XXL, XXIV. Fig. 4.) 

Umtjs Oweni, Leidy : Proc. Acad. Nat. Sci., 1851, v., 327. 

Testudo Oweni, Leidy: Proc. Acad. Nat. Sci., 1852, vi., 59; Owen's Rep. of a Gcol. Surv. of Wise, etc., 568. 

This species is established upon a nearly entire carapace and plastron. The 
former has nearly the same degree of convexity and form of that of the Box Tor- 
toise (Clstudo Carolina). 

The costal plates had not yet united by suture with the marginal plates. 

The latter, at the sides of the carapace, are vertically convex, with their upper 
border elevated two and a half inches above the level of the sternum. Anteriorly 
and posteriorly they are less inclined than the contiguous dorsal plates. 



TESTUDO. 107 

The sternum is flat, except at its union with the carapace, in which position it is 
convex, and anteriorly is turned upward, and has its margin angularly convex; and 
posteriorly it is emarginate. 

Plates of the Carapace. — (PI. XXI. 1.) In the specimen there are ten vertebral 
plates. The first is one and a half inch long, by ten lines broad. Those suc- 
ceeding to the eighth inclusive are hexahedral ; the second to the fifth are nearly 
equal in size ; those to the eighth successively decrease. 

The second vertebral plate articulates with the first and second pairs of costal 
plates ; the third with the second and third ; and so on successively to the eighth 
plate inclusive. 

The tenth vertebral plate is fourteen lines long by seventeen broad, and is divided 
into two nearly equal triangles by the posterior border of the last vertebral scute. 

The first costal plate is three inches long by two broad, and articulates with the 
first to the commencement of the fourth marginal plate. 

The nuchal plate is three and a quarter inches broad, and is equal to the first 
vertebral scute. The pygal plate is twenty-two lines broad. 

Plates of the Plastron. — (PI. XXI. 2.) The entosternal plate is pyriform, and is 
two inches four lines long and broad. Its anterior extremity borders on the posi- 
tion of the gular scutes, and posteriorly it extends to the humeral scutes. 

The anterior margin of the episternal plates is convex. Their length obliquely 
at the middle is equal to that of the preceding plate. 

The hyosternal plates are three and a half inches long from their anterior angle, 
and they articulate with the third to the angle of the sixth marginal plates 
inclusive. 

The hyposternal plates are two and a half inches long at their middle, are slightly 
oblique at the posterior margin, and articulate with the sixth and seventh marginal 
plates. 

The xiphisternal plates include an acute notch posteriorly, and are two and a 
quarter inches long. 

The suture between the marginal plates of the carapace and those of the plastron, 
and the junction of the contiguous scutes from two irregular undulant intersecting 
lines. 

Scutes of the Carapace. — (PI. XXI. 1.) The second and third vertebral scutes 
are nearly equal in size, each being two inches seven lines broad, the former two 
inches long, and the latter one line longer. Their lateral margins are bow-formed, 
and the anterior margin of the second is nearly straight, while that of the tliird is 
convex forward. 

The fourth vertebral scute is slightly broader than long, being two inches two 
lines in the former direction, and two inches one line in the latter. Its lateral 
margins, also, are bow-formed, and converge behind, and the anterior margin is 
angular forwards. The nuchal scute is four lines broad. 

The gular scutes together are two and a quarter wide, are convex posteriorly, 
and do not encroach upon the position of the entosternal plate. 

Scutes of the Plastron. — (PI. XXI. 2.) The pectoral scutes are three and a 



208 TESTUDO. 

quarter inches long, and have their posterior border a little behind the axillary 

notches. 

The humeral scutes are about seven and a half lines long where they come in 
contact, but outwardly expand to two and a half inches. They join the axillary 
scute, the posterior angle of the fourth, the whole of the fifth, and the lower half 
inch of the anterior margin of the sixth marginal scutes. 

The abdominal scutes are three inches in length, and join the sixth and seventh 
marginal, and the inguinal scutes. 

The length of the femoral scutes is two and a quarter inches, and that of the 
caudal scutes where they are conjoined, is one inch five lines. 

The axillary scute is placed upon the anterior angle of the hyosternal and the 
postero-inferior margin of the third marginal plates, l^etween the fourth marginal 
and the humeral scutes. 

The inguinal scute rests upon the hyposternal and seventh marginal plates, be- 
tween the abdominal and seventh and eighth marginal scutes. 

MEASUREMENTS. 



Inches. 


Lines. 


10 





7 





13 


6 


15 


6 


5 


6 


2 


6 



Length of sternum in the median line ...... 

Breadth of sternum at the suture of the hyo- and hyposternal plates 
Estimated length of antero- posterior curve of the carapace 
Length of transverse curve from the level of the sternum 

Height 

Length of the sixth marginal plate ...... 

Height of the upper edge of the lateral marginal plates from the level of the 

sternum ........-••• 3 

This species is respectfully dedicated to Dr. David Dale Owen, of New Harmony, 
Indiana, whose many contributions to Palaeontology and Geology have rendered 
him distinguished in science. 



Te!$tu<lo Cnlbertf^onii, Letdy. 

(Plates XXII., XXIV. Fig. 2.) 

Emys Culherlsonii, Leidy : Proc. Acad. Nat. Sci., 1852, vi., 34. 

Testudo Culbertsonii, Leidy : Proc. Acad. Nat. Sci., 1852, vi., 59 ; Owen's Rep. of a Geol. Surv. of Wise, etc. 
569. 

This species is established upon a nearly entire carapace and plastron in' the col- 
lection of Dr. Owen. The specimen upon one side is a little crushed out of its 
original form; and it is much larger than that upon which is founded the Testudo 
Oweni, and is relatively less convex and high in comparison with its length and 
breadth, and also is less abruptly retuse posteriorly. 

The sternum in the specimen is concave, indicating a male individual, and ante- 
riorly it does not turn upward. 

The costal plates, though in conjunction with the marginal plates, had not yet 
united by suture. 

The lateral marginal plates are vertically convex, and three and a half inches 



TESTUDO. 109 

long in the curve, and became inferior at their lower fourth, but have no salient 
angle. Anteriorly and posteriorly to the union of the carapace and plastron, the 
marginal plates are oblique. The line of suture of the two former is undulant, as 
is also the corresponding line of conjunction of the scutes; the two intersecting 
each, other several times. These lines are less irregular in their course than in 
Tt'stuclo Otvetii, and on the two sides are nearly parallel. The axillary and inguinal 
notches present directly downward. 

Plates of the Carapace. — (PI. XXII. 1.) The carapace has eleven vertebral 
plates. The first of the series is quadrilateral, with convex sides, and is two and 
a quarter inches long and one and a half broad. The second is octohedral, with 
alternating long and concave and short and straight sides ; or it is quadrilateral, 
with concave sides and the angles truncated. It is one and a half inch long and 
one inch and seven lines broad, and articulates with the anterior three paix's of 
costal plates. The third vertebral plate is quadrilateral, with convex sides, and it 
is one and a half inch long and one inch ten lines broad, and articulates with the 
third pair of costal plates. 

A similar arrangement to that described of the second and third vertebral plates 
exists also in the Gopher {Testudo polyphemus). 

The fourth to the eighth vertebral plate inclusive are hexahedral, of which the 
fifth is the largest, while the others decrease in succession from the fourth to the 
last of the numlser. 

The ninth vertebral plate is an accessory to the usual number, is quadrate, with 
convex sides, and articulates with the eighth pair of costal plates. 

The penultimate V-shaped plate incloses one-half of that succeeding, which is 
one and a half inch long and two and a quarter inches broad. 

The first costal plate is five and a quarter inches long by three inches broad, and 
articulates with three-fourths of the first marginal plate, all of the second, and 
three-fourths of the third. 

The nuchal plate comes in contact with the position of the first costal scute at 
the anterior angle, in which position it is five and a quarter inches broad, and equal 
to the first vertebral scute. 

Plates of Hie Plastron. — (PI. XXII. 2.) The entosternal plate is pyriform, and 
is three inches five lines long and two lines broader. Its neck extends three-fourths 
of an inch upon the position of the gular scutes, and its base is about a third of an 
inch removed from the humeral scutes. 

The hyosternal plates are over five inches in length, and articulate with the third 
to the angle inclusive of the sixth marginal plates. 

The hyposternal plates are four inches long at their middle, and articulate with 
the sixth and seventh marginal plates. 

The xiphisternal plates include a notch behind, and in the median line of the 
sternum are three inches long. 

Scutes of the Carapace. — (PI. XXII. 1.) The second and third vertebral scutes 

are three inches long; the former three and a half, the latter four inches broad. 

The sides are bow-shaped, and nearly parallel. The anterior margin of the second 

is deeply concave; that of the third bow-shaped. The fourth vertebral scute is 

15 



210 TESTUDO. 

three inches three lines broad, and is seven lines longer. It has bow-shaped sides, 
converging posteriori}', and its anterior margin is angular. The last vertebral scute 
is prolonged anteriorly as a cup-shaped process. 

The nuchal scute is five lines broad, and the pygal scute four and a half inches. 

Scutes of the Plastron. — (PI. XXII. 2.) The gular scutes are acute behind, and 
encroach upon the position of the entosternal plate. 

The pectoral scutes are five and a quarter inches long, and extend posteriorly to 
the axillary notches. 

The humeral scutes are about an inch long, but expand outwardly, and join the 
axillary and the fourth and fifth marginal scutes. 

The abdominal scutes are four and a half inches long at their middle, and join 
the sixth and seventh marginal and the inguinal scutes. 

The femoral scutes are three and a half inches long, and the caudal scutes, where 
they come into contact, are one and three-quarter inches. 

The axillary scute is situated at the outer side of the notch, and rests upon the 
inferior angle of the hyosternal plate between the humeral and fourth marginal 
scutes. The inguinal scute rests upon the hyposternal and seventh marginal plates, 
between the abdominal and seventh and eighth marginal scutes. 

MEASUREMENTS. 

Inches. 

Estimated length of sternum in the nierlian line ....... 15 

Breadth of sternum ............ 11 

Estimated length of the antero-posterior curve of the carapace .... 22 

Estimated length of transverse curve ......... 22 

Height 6i 

Length of sixth marginal plate .......... 3f 

Height of lateral marginal plates above level of the sternum .... 4 

This species is respectfully dedicated to Mr. Thaddeus A. Culbertson, through 
whose interested zeal so many of the animal remains of Nebraska have been 
discovered. 

Testiido lata, Leidy. 

(Plates XXIII., XXIV. Fig. 1.) 
Testiido lata, Leidy: Proc. Acad. Nat. Sci., 1851, v., 173; Owen's Rep. of a Geol. Surv. of Wise, etc., 572. 

This species is the largest of any of the turtles brought from Nebraska, and was 
obtained by Mr. Thaddeus A. Culbertson. The specimen upon which it was 
established consists of a carapace and plastron broken into two pieces and otherwise 
much mutilated. A considerable portion of the carapace is lost, and the sternum 
is crushed inward from its articulation with the former. 

The form of the species is very much like Testucio Culhertsonii, and it may 
possibly be the same, though it differs in several of its anatomical details. 

In the specimen, the costal plates are united to the marginal plates by close suture. 

The lateral marginal plates are vertical at their upper four-fifths, and those ante- 
riorly and posteriorly are oblique. 



TESTUDO. Ill 

The sternum appears to have been quite flat, and the axillary and inguinal 
notches are directed downward. 

Plates of the CarcqMce. — (PI. XXIII. 1.) The first vertebral plate has convex 
sides, and has the form of a sugar-loaf; it is two and three-quarter inches long and 
one inch seven lines broad at its middle. 

The second and third, and portions of the fourth and seventh, and the eighth 
vertebral plates, preserved in the specimen, are hexahedral, and the first two are 
subequal. 

The ninth, or inverted V-shaped vertebral plate, is a little depressed anteriorly to 
receive the border of the plate in advance. 

The tenth, or rhomboidal vertebral plate, is two and thi'ee-quarter inches long, 
and three and a half broad. 

The first costal plate is six and three-quarter inches wide and four and a half 
inches antero-posteriorly, and articulates with the first to the third marginal plates 
inclusive. 

The nuchal plate, as in all the species described, reaches only the anterior angle 
of the position of the first costal scute, and there measures seven inches in breadth. 

Plates of the Plastron. — (PI. XXIII. 2.) The entosternal jjlate is pyriforni, and 
is four inches long and three-fourths of an inch broader. 

The hyosternal plates are seven and a quarter inches long, and articulate uith 
the marginal plates from the third to the middle of the sixth inclusive. 

The hyposternal plates are five and a half inches long, and articulate with the 
sixth and seventh marginal plates. 

The xiphisternal plates, where in contact, measure four inches in length. 

Scutes of the Carapace. — (PI. XXIII. 1.) The second vertebral scute is quadri- 
lateral, and is four inches long and three-fourths of an inch greater in its breadth. 
The lateral margins are slightly bow-formed and parallel, and the anterior and 
posterior borders are concave. 

The last vertebral scute is prolonged anteriorly into a cup-shaped process, 
receiving the scute in advance. 

Scutes of the Plastron. — (PL XXIII. 2.) The gular scutes are angular posteriorly, 
and encroach for one inch upon the position of the entosternal plate. 

The humeral scutes are one and a quarter inch long internally, and outwardly 
join the axillary and the fourth to the middle of the si.xth marginal scute. 

The abdominal scutes are five and a half inches long, and join the sixth and 
seventh marginal and the inguinal scutes. 

MEASUREMENTS. 

Inches. 

Estimated length of the sternum ......... 21 

Breadth of the sternum ........... 15 

Estimated length of antero-posterior curve of the carapace ..... 27 

Estimated length of transverse curve . . . . . . . . '^ • 27 

Height above level of the sternum ......... 8 

Length of Literal marginal plates ......... 5 



SYNOPSIS 



GENERA AND SPECIES OF EXTINCT MAMMALIA AND CHELONIA DESCRIBED IN THIS WORK. 



MAMMALIA. 
UNGULATA PARIDIGIT AT A. 

KUMINANTIA. 
POEBROTHERIUM. Hornless; without lachrymal fossae; auditory bullae very large and inflated; 
orbits closed by a post-orbital arch. Lower jaw with an angular apophysis. Dental formula : in. — | '- 

c. — ^ — ^ p.m. in. =38? True molars composed as in existing ruminants; premolars 

most like those of the recent Musks ; first premolar removed from the others by a hiatus. 
PoEBROTHERiuM WiLSONii. Unique species. 

AGRIOCHOERUS. Hornless; without lachrymal fossae; orbits open behind. Dental formula: 

. 3?— 3? 1? — 1? 4? — 4? 3—3 ,,9 rr , * * i a .. . c .u 

*i- -r^ T7. c. =— p.m. — m. z=: 44 ( I rue molars constructed alter the type of those 

4? — 4? 1? — 1? 3? — 3? 3 — 3 

of existing ruminants ; premolars with from one to four lobes, modified in form from those of the true 

molars. 

Ageiochoeeus antiquus. Unique species. 

OREODON. Hornless ; with a sagittal crest ; with the pars-squamosa of the temporal bone relatively 

as well developed as in the Camel ; auditory bullaa none ; orbits closed behind ; very large lachrymal 

3 3 J 2 4 4 3 3 

fossae. Dental formula : in. c. p.m. m. ^= 44. Teeth of both jaws forming 

nearly closed rows. True molars constructed after the type of those of existing ruminants ; premolars 
with one or two lobes. Upper canine with a curved, trihedral, pyramidal crown ; lower canine with a 
compressed conoidal crown. Incisors with flattened crowns. 

1. Oeeodon Culbertsonii. About the size of the Wolf of Pennsylvania. 

2. Oeeodon geacilis. About two-thirds the size of the former. 
8. Oeeodon ma joe ? A little larger than Oreodon Culbertsonii. 

EUCROTAPHUS. Cranium constructed like that of Oreodon, except that it possesses large, inflated 
auditory bulla;. Dental formula : as in Oreodon f 

1. EucEOTAPHUS AUEITUS. Auditory bullae laterally compressed spheroidal. 

2. ElucEOTAPHUs Jacksoni. Smaller than the preceding ; auditory bulla; mammillary. 



114 SYNOPSIS. 



ORDINARIA. 

ARCHAEOTHERIUM. With a sagittal crest; orbits closed by a post-orbital arch; glenoid arti- 
culation transverse. Lower jaw with a basal apophysis as in AtUhracotherium. Dental formula : 

^ ? -| 9 1 f Af I ? Q Q 

in. '- c. —i 1 p.m. — '- m. . Crowns of upper true molars quadrate, with two trans- 

? ? 1? it^ 4? 4? 3 — 3 '■^ ' 

verse rows of three conical tubercles or lobes ; the lower ones with two transverse pairs of tubercles, of 
which that antero-iuternally is subdivided. Last upper premolar bilobed; penultimate upper molar com- 
pressed conoidal. Last lower premolar compressed conoidal. 

1. ARCHAEOTHERIUM MoRTONi. Head about the size of that of the Lion. 

2. ARCHAEOTHERIUM ROBUSTUM. Rather larger than the preceding. 



UNGULATA IMPARIDIGITATA^ 

SOLIPEDIA. 
ANCHITHERIUM. With a short sagittal crest ; forehead broad and large ; orbits large. Dental 

formula: in. — ^^^^ c. m. ' . Molars constructed after the type of those of Palaeotherium. 

3—3 1—1 7—7 

Anchitherium Bairdii. About the size of Anchithcrium aureliancnse. 

ORDINARIA. 

TITANOTHERIUM. Dental formula as in Palaeotherium? Upper molars quadrate, complex, inter- 
mediate in form to those of Palaeotherium and Rhinoceros ; their outer side without the double arched 
ridge characteristic of the former, and without the anterior marginal fold characteristic of the latter. 
Lower molars like those of Palaeotherium, but possessing no inner basal ridge. 

TiTANOTHERiuJi Proutii. Unifjuo species. 

PALAEOTHERIUM. Dental formula : in. ?-^^ c. 1^^ p.m. izif m. ?-i:i| = 44. Upper 

3 — 3 1 — 1 4 — 4 3 — 3 

molars quadrate, complex ; with an external double-arched ridge. Lower molars bilunate; the last trilunate. 
Palaeotherium GiGANTEUiM. Twice the size of the Palaeotherium magnum^ being the largest spe- 
cies of the genus. 

RHINOCEROS. With a nasal or frontal horn, or both, or none. Dental formula : in. , or 

1 — 1 2 — 2 — 7 — 7 , , , . , , 

:j T, or c. m. -. Upper molars quadrate, complex ; with a characteristic antero- 

external fold. Inferior molars composed of a pair of right angled crescentoid lobes. 

1. Rhinoceros occidentalis. With a sagittal crest; frontal horn none; nasal horn? forehead 
broad and flat. Three-fourths the size of Rhinoceros indicvs. 

2. Rhinoceros Nebrascensis. With a sagittal crest; frontal horn none; nasal horn? Three- 
fourths the size of Rhinoceros occidentalis. 



SYNOPSIS. 115 



CARNIVORA. 

DIGITIGRADA. 

q q 1 "I A A 

MACHAIRODUS. Dental formula: in. c. m. Superior canine long, curved, 



compressed laterally. Inferior carnassial tooth with a third lobe. 

Machairodus primaevus. a little smaller than the American Panther. 



CHELONIA. 

TESTUDO. Carapace with 10 vertebral plates, 8 pairs of costal plates, and 11 marginal plates each 
side of a symmetrical nuchal and pygal plate ; and 5 vertebral scutes, 4 pairs of costal scutes and 1 1 
marginal scutes each side of a narrow nuchal and a broad undivided pygal scute. First vertebral plate 
oblong quadrilateral ; the succeeding plates to the eighth inclusive hexahedral ; penultimate plate inverted 
V-shaped ; the last rhomboidal. Plastron composed of an entosternal and 4 pairs of lateral plates, and 
furnished with 8 pairs of scutes. 

1. Testudo Nebrascensis. Small, emydiform. Entosternal plate encroaching upon the position of 
the gular scutes, but usually not reaching that of the pectoral scutes. 

2. Testudo hemispheeica. Hemiovoid. Entosternal plate encroaching upon the position of the 
gular scutes, and reaching that of the pectoral scutes. 

3. Testudo Oweni. Robust. Entosternal plate not encroaching upon the position of the gular 
scutes, but reaching that of the pectoral scutes. 

4. Testudo Culbertsonii. Large, depressed. Entosternal plate encroaching upon the positi(fti of the 
gular scutes, but not reaching that of the pectoral scutes. 

5. Testudo lata. It is possible that this species and the last indicated maybe the same. In the speci- 
mens upon which these two were proposed, the latter is very much the larger, but the former is immature. 
In the former, also, the second vertebral plate is octohedral, while in the latter it has the normal hexahedral 
form, but this variation may be an individual peculiarity only. 



INDEX. 



[Synonymcs and names incidentally used are in Roman.] 



Aceratherium, 80, 81. 

incisivum, 74, 80, 84, 90. 

Nebrascensis, 86. 
Agriochoerus, 24, 56, 113. 

antiquum, 24, 113. 
Amphigonus Broderipii, 7. 

Prevostii, 7. 
Anchitherium, 67, 68, 69, 70, 91, 114. 

aurelianense, 07, 68, H4. 

Bairdii, 67, 68, 70, 114. 

Dumasii, 67. 

Ezquerrae, 67. 
Anomodon Snyderi, 9. 
Anoplotherium, 7, 17, 24, 25, 29, 30, 31, 32, 36, 

37, 38, 40. 
Anlhracotherium, 18, 38, 62, 114. 
Antilope, 18. 
Archaeotherium, 57, 59, 62, 63, 64, 66, 114. 

MoRTONi, 57, 58, 66, 114. 

ROBUSTDM, 66, 114. 
Arctodon, 66. 
Auchenia, 17. 
Aulaxodon, 9. 
Balfena Pala3atlantica, 8. 

prisea, 8. 
Basilosaurus, 8. 

cetoides, 8. 

pygmaus, 8. 

serratus, 8. 
Bison americanus, 12. 

antiquus, 9. 

latifrons, 9. 
Bootheiium, 29, 31. 
Bootherium bombifrons, 9. 

cavifrons, 9. 
Bos, 18. 

bombifrons, 9. 

latifrons, 9. 

Pallasii, 9. 
Caenotherium, 38. 
Camelopardalis, 17. 
Camelus, 17. 
Castor fiber, 9. 

16 



Castoroides obioensis, 9. 
Cervus, 9, 17. 

americanus, 8, 9. 
Chaliootberium, 17, 38. 

Choeropotamus, 18, 57, 58, 59, 60, 61, 62, 63. 
Cistudo Carolina, 106. 
Cotjlops, 29. 

speeiosa, 45, 47. 
Delpbinus Calvertensis, 8. 

Conradi, 8. 

vermontanus, 10. 
Dicbobime, 17. 
Dichodon, 38. 
Dicotyles, 18. 

costatus, 9. 

depressifrons, 9. 

labiatus, 60. 

torquatus, 9. 
Dorcatherium, 17, 20, 21. 
Elaphus americatius, 9. 
Elephas, 18. 

americanus, 9. 

primigenius, 9. 
Emys, 103. 

Lemispheriea, 105. 

Oweni, 106. 

Culbertsonii, 108. 
Entelodon, 57, 62, 64. 

magnum, 62, 63. 
Eqnus, 18. 

americanus, 9. 

caballus, 10. 

curvidens, 10. 

major, 10. 
Ereptodon priscus, 10. 
Eubradys antiquus, 10. 
Eucboerus macrops, 9. 
Edcrotaphus, 56, 113. 

auritus, 56, 57, 113. 

Jacksoni, 56, 57, 113. 
Felis, 58, 96, 97, 98, 99. 

atrox, 9. 

concolor, 96, 



118 



INDEX. 



Harlanus americanus, 9. 
Hipparion, 18. 

venustum, 9. 
Hipparitherium, G7. 
Hippopotamus, 18, 59, 62. 
Hyopotamus, 26, 38, .39. 

bovinus, 45. 

vectianus, 45. 
Hyracotherium, 18, 57, 59, 62, 63. 
Wachairodus, 18, 95, 96, 97, 98, 99, 115. 

cultridens, 98, 99. 

ncogaeus, 96, 98, 99. 

PRIMAEVUS, 95, 115. 
Macrauchenia, 17. 
Manatus, 10. 
Mastodon, 18. 

giganteus, 9. 
Megalonys dissimilis, 9. 

Jeifersonii, 9. 

laqueatus, 9, 10. 
Megatherium, 9. 

Cuvieri, 9. 

mirabile, 9. 
Merycoidodon, 29. 

Culbertsonii, 29, 45, 52. 

gracilis, 53. 

major, 55. 
Merycopotamus, 25, 38. 
Blicrolestes antiquus, 7. 
Moschus, 17. 

moschiferus, 20. 
Mososaurus, 8. 
Mylodon Harlani, 10. 

Oreodon, 29, 30, 35, 36, 37, 40, 41, 42, 43, 44, 45, 
46, 47, 55, 56, 113. 

Culbertsonii, 45, 48, 50, 51, 52, 53, 55,113. 

gracilis, 53, 54, 55, 113. 

MAJOR, 55, 113. 
Oromys j3ilsopi, 9. 
Orycterotherium Missouriense, 10. 

Oregonensis, 10. 
Osteopera platycephala, 10. 
Ovis, 18. 

mammilaris, 9. 

montana, 12. 
Palaeotherium, 18, 38, 44, 67, 68, 70, 71, 72, 73, 
74, 75, 78, 91, 114. 

aurelianense, 67. 

Bairdii, 67. 

equinum, 67. 

OIGANTEUM, 78, 114. 

hippoides, 67. 
magnum, 114. 
mouspessulanum, 67. 



Proutii, 72, 78. 
Phascolotherium Bucklandii, 7. 
Phoca Wymani, 8. 
Phocodon, S. 

Platygonus conapressus, 9. 
Pleurodon, 9. 
Poebrotherium, 19, 20, 21, 22, 113. 

WiLSONI, 19, 113. 
Pontogeneus prisons, 8. 
Priscodclphinus gvandaevus, 8. 

Harlani, 8. 
Procyon priscus, 9. 
Protochoerus prismaticus, 9. 
Rhinoceroides alleghanieusis, 10. 
BniNOCEROs, 18, 37, 61, 72, 75, 76, 77, 79, 80, 81, 
83, 85, 86, 90, 91, 93, 114. 

americanus, 72, 76. 

incisivus, 79, 80. 

indicus, 79, 81, 82, 83, 84, 85, 88, 89, 91, 
114. 

luinutus, 79. 

Nebrascensis, 86, 87, 90, 93, 114. 

occiDENTALis, 81, 87, 88, 89, 90, 91, 114. 

tichorinus, 91. 
Rorqualis australis, 10. 
Sargodon, 7. 
Sargus, 7. 

Stylemys Nebrascensis, 103. 
Sus, 18. 

americana, 9. 
Tapirus, 18. 

americanus 9. 

Haysii, 9. 

mastodontoidcs, 9. 
Tclerpeton elginense, 7. 
Testudo, 101, 102, 103, 115. 

Culbertsonii, 108, 110, 115. 

hemispherica, 105, 115. 

L.\TA, 110, 115. 

Nebrascensis, 103, 115. 

OwENi, 106, 108, 109, 115 

polyphcmus, 103, 109. 
TiTANOTHERIUM, 72, 76, 78, 91, 114. 

Proutii, 72, 76, 114. 
Tricbccus, 10. 

virginianus, 10. 
Trichecus rosmaruS) 10. 
Ursus, 95. 

americanus, 9. 

amplidens, 9. 
Zeuglodon brachyspondylus, 8. 

cetoides, 8. 

macrospondylu.s, 8. 

pygmoBus, 8. > 



EXTLANATION OF THE TLATES, 



PLATE I. 

All the figures are of the natural size. 

Figs. 1-4. Poehrotlicruim VfHsoni. 

Fig. 1. View of the right side of the ftice. The top of the head and the cranium proper are broken 
away. To the left is represented the angular apophysis, and in the concavity above this is the very large os 
tjmpanica. The upper jaw contains the fir^t premolar, separated from the others by a hiatus, the temporary 
molars, and the permanent true molars. The lower jaw contains the temporary molars and the permanent 
true molars. 

Fig. 2. Upper view of the nasal extremity of the face, eshibitiug its great narrowness. 

Fig. 3. View of the masticating surfaces of the upper molars of the specimen 1. 

Fig. 4. View of the masticating surfaces of the lower molars of the specimen 1. 

Figs. 5-10. Ai/riochoeriis antiqnus. 

Fig. 5. View of the right side of the face. The specimen is much mutilated, but the orbit is observed 
not to be closed by an arch posteriorly. In the upper jaw the inner part of the second premolar of the left 
side is visible, and succeeding it upon the right side the posterior two premolars and the true molars. In 
the portion of lower jaw are visible the posterior two premolars and the true molars. 

Fig. G. Inferior view of the upper jaw, exhibiting the triturating surfaces of the molars, five of which 
are preserved on the right side and six upon the left. The hard-palate is obscured by a mass of very dense 
matrix, which would endanger the integrity of the specimen to remove. 

Figs. 7, 8. Triturating surfaces of the posterior five inferior molars of the right and left sides. 

Fig. 9. Triturating surfaces of the first and second true inferior molars of the left side, somewhat worn. 

Fig. 10. Triturating surfaces of the posterior two true superior molars of the left side, a little worn, and 
probably belonging to the same individual as the last specimen. 



PLATE II. 

Figures of the natural size. 

Oreodon Culhertsmiii. 

Fig. 1. The right side of a much fractured skull with the lower jaw, of an adult, containing the full 
complement of teeth quite perfect. In the upper jaw are three incisors, the canine, four premolars, and 
three true molars; in the lower jaw, four incisors, the canine, three premolars, aud three true molars. 

Fig. 2. Front view of the three upper and four lower incisors of the right side, from the same specimen 
as the preceding figure. 

Fig. 3. The left side of another adult specimen, which is in a comparatively fine state of preservation. 
It has lost the nasal extremity, post-orbital arch, and zygoma; the latter, however, was entire when the 
specimen was received, but was afterwards accidentally broken ofi" and lost. The upper jaw contains the 
seven molars, and the lower jaw the canine and six molars. 

' All the Plates are drawn directly from Nature, on stone. Vlates 1, 2, 3, 8, 9, 10, 11, Vi, are by Mr. A. Sonrel, of 
Woburn, Mass.: Plates 4, 7, 13, 14, 16, 20, 21, 22, 23, 24, by Mr. A. Frey, of Philadelphia: Plates 5, 6, 12, by Mr. 
A. J. IbbotsoD, of Philadelphia: Plates 18, 10, by Mr. F. Schell, of Philadelphia: and Plate 17 by Mr. J. Butler, of 
Philadelphia. 



120 EXPLANATION OF THE PLATES. 



PLATE III. 

Figures of the natural size. 

Oreodon CiMicrtsonli. 

Fig. 1. View of the base of a skull containing on both sides all the molars perfect, and on the left side 
the canine in the same condition. From an adult male individual. The molar teeth are four premolars 
and three true molars. 

Fig. 2. View of the left side of the same specimen as the last, exhibiting the canine and the succeeding 
series of molars. 

Fig. 3. Inner view of a series of inferior molars of the right side, restored from several different indi- 
viduals. The teeth consist of three premolars and three true molars. 

Fig. 4. View of the masticating surface of the same series as the last. 

Fig. 5. External view of a right posterior inferior molar, removed from its socket. 

Fig. 6. View of the masticating surface of the same tooth as the last. 



PLATE IV. 

Figures of the natural size. 

Figs. 1—5. Oreodon C'tdb/i-fsonii'. 

Fig. 1. Upper view of the skull, from the same specimen as figure 3, Plate IL 

Fig. 2. View of the inion or occipital region, from the same .specimen as the preceding. 

Fig. 3. View of a specimen upon the left side of the face, exhibiting the orbit and lachrymal depression 
entire. 

Fig. 4. Greater portion of tlie left side of the lower jaw of a young individual, containing the first pre- 
molar, the succeeding two temporary molars, and the permanent true molars, of which tlie last is only 
partially protruded. 

Fig. 5. View of the triturating surfaces of the premolars and last temporary true molar, from the same 
specimen as the last. 

Fig. 6. Oreodon major. View of the triturating surfaces of the superior true molars, of the right side, 
considerably worn. 



PLATE V. 

All tlie figures are of the natural size. 

Figs. 1, 2. Oreodon Culhertsovii. 

Fig. 1. View of the left side of the skull of a j'oung individual. The zygoma, end of the nose, and 
nearly all the teeth are broken away. In advance of the orbit is observable the large lachrymal depression. 

Fig. 2. View of the base of the same specimen as the last. Upon the right side of the jaw all the 
molars are preserved, consisting of the temporary series and the permanent true molars. The foramina 
visible at the base of the cranium, proceeding backward on each side, are the rotundum, ovale, lacerum, and 
condyloideum. 

Figs. 3, 4. Oreodon graciUs. 

Fig. 3. View of the base of the skull of a young animal. The teeth visible on the left side, proceeding 
backward, are, a fragment of the canine, the two fangs of the first premolar, three succeeding temporary 
molars, and two permanent true molars. On the right side are preserved the last temporary true molar and 
the succeeding two permanent true molars. The oblique lines indicate a portion of the matrix, in which 
the specimen was originally imbedded. 

Fig. 4. Superior view of the same specimen as the last. It presents a remarkable degree of flatness of 
the forehead. 



EXPLANATION OF THE PLATES. 121 



PLATE VI. 

All the figures are of the natural size. 

Figs. 1—7. OreoJon gracilis. 

Fig. L Upper view of a broken skull. 

Fig. 2. Base view of the same specimen. On (he right side the jaw contains entire the last, premolar 
and all the true molars of the permanent series. 

Fig. 3. View of the right side of the same specimen as the last. 

Fig. 4. View of the left side of a fiice and lower juw of another adult specimen. The upper jaw exhibits 
the last two molars, and the lower jaw the last premolar and all the true molars. The orbit is entire. 

Fig. 5. View of the masticating surfoces of the lower molars of the specimen last indicated. 

Fig. 6. View of the left side of the skull and lower jaw of a young iudividual, being the same specimen 
represented in Figs. 3, 4, Plate V. The orbit is ncarlj entire. The upper jaw exhibits a series of the first 
premolar restored, the three temporary molars, and the anterior two permanent true molars. The lower 
jaw contains two temporary molars and the succeeding two permanent true molars. 

Fig. 7 represents the masticating surfaces of the inferior teeth last mentioned. 

Figs. 8-11. Oreodon Culhertsonii. 

Fig. 8. Masticating surfaces of the inferior posterior five molars of the left side, very much worn. 

Fig. 9. Inner view of the same teeth as those last indicated. 

Fig. 10. Fragment of the lower jaw of the right side of a young animal. It contains the broken canine, 
and the entire last temporary molar and the succeeding two permanent true molars. 

Fig. 11. Outer view of the same specimen as the last. 



PLATE VII. 

Figures all the size of nature. 

Figs. 1-3. Eiicrotaphns auritus. 

Fig. 1. View of the left side of a portion of the cranium, exhibiting the pars squamosa and the parietal 
bone. 

Fig. 2. Upper view of the same specimen. 

Fig. 3. View of the base of the same specimen, exhibiting the large o.ssa tympanica, portions of the 
glenoid articulations, and the occipital and sphenoidal bodies. 

Pigs. 4-6. Eticroto2')lius Jacksoni. 

Fig. 4. View of the right side of a portion of the craniun), exhibiting the pars squamosa, the post glenoid 
tubercle, the meatus auditorius externus, and part of the parietal bone. 

Fig. 5. Upper view of the same specimen as the last. The parietal crest is broken away. 

Fig. 6. View of the base of the same specimen. It exhibits one os tympanica with its superficies broken 
off, one glenoid articulation, and the occipital and sphenoidal bodies. 



PLATE VIII. 

Figures of the natural size. 

Archaeotherimn Morton i. 

Fig. 1. View of the base of the skull of a young animal. The deciduous teeth had not yet been shed, 
and only the first two permanent true molars had protruded. Upon the left side are exhibited the last two 
permanent premolars, exposed by breaking away deciduous teeth occupying a corresponding position; the 
first two permanent true molars, which are in place; and the last molar, which was exposed by breaking 
away the bone. Upon the right side are exhibited the last two deciduous molar.s, succeeded by the three 
permanent true molars. 



122 EXPLANATION OF THE PLATES. 

In the specimen, a large mass of matrix occupies the inner surface of the right zygoma, which is allowed 
to remain so as to give strength to the latter. 

Fig. 2. Fragment of the lower jaw of the right side, exhibiting the basal apophysis, and also presenting 
to view the greater portion of the last temporary molar, beneath which is exposed the last permanent pre- 
molar, and posterior to it the protruded first permanent true molar. 



PLATE IX. 

Archaeotlwrium Morton L Figures 1 to 3 are half the diameter of nature, and the remaining figures are 
of the natural size. 

Fig. 1. View of the right side of the skull. The orbital entrance is entire; and in the upper jaw the 
posterior two temporary molars and tlie anterior two permanent molars are seen. The dotted line represents 
the upper part of the face restored from another specimen. 

Fig. 2. Upper view of the same specimen represented in figure 1. The ossa nasi are represented, in dot- 
ted lines, from another specimen. 

Fig. 3. V^icw of the left side of a facial fragment, from an old individual, containing the posterior two 
permanent premolars. 

Fig. 4. View of the triturating surfaces of the teeth represented in figure 3. 

Fig. 5. View of the triturating surfaces of the anterior tw'o permanent true molars of the left side of the 
upper jaw; from an adult individual. 



PLATE X. 

Figs. 1-7. Arcliacothcriiim MortoiiL All the figures of the natural size except 6 and 7. 

Fig. 1. Outer view of the last two premolars and the true molars of the left side of the upper jaw, from 
the same specimen as Plate VIII., figure 1. 

Fig. 2. Outer view of the last premolar and the true molars of the left side of the lower jaw. 

Fig. 3. View of the masticating surfaces of the same teeth represented in figure 2. 

Fig. 4. Inner view of the last premolar of the left side of the lower jaw; from the same specimen repre- 
sented in figure 2. 

Fig. 5. Inner view of the penultimate premolar of the left side of the upper jaw; from the same speci- 
men represented in figure 1. 

Fig. 6. Half the diameter of nature. View of the inion or occipital region. Upon the right of the figure, 
when placed in proper position, the large infundibular expansion of the root of the zygomatic process is 
observed. 

Fig. 7. Half the diameter of nature. Inner view of the angular portion of the right side of the lower jaw. 
Near its middle the entrance to the dental canal is observable. 

Figs. 8-13. Archaeotheriuin rohusfum. All the figures of the natural size. 

Fig. 8. Outer view of the crown of a canine. 

Fig. 9. Anterior view of the same specimen as the preceding. 

Fig. 10. View of the triturating surface of a fragment of an inferior second true molar of the left side. 

Fig. 11. View of the outer surface of the same specimen represented in figure 10. 

Fig. 12. View of the triturating surface of a fragment of an inferior last true molar of the left side. 

Fig. 13. View of the inner surface of the same specimen represented in figure 12. 

Figs. 14-21. Anchilheritim Bairdli. All the figures are of the natural size. * 

Fig. 14. Outer view of the posterior five inferior molar teeth of the left side. The last of the series has 
lost its hinder lobe. 

Fig. 15. View of the masticating surface of the posterior three inferior molars of the left side. From 
an older individual than the preceding specimen. 

Fig. 16. Outer view of an unworn inferior molar of the right side. 

Fig. 17. Inner view of the same specimen as figure 16. 



EXPLANATION OF THE PLATES. 123 

Fig. 18. Outer view of tbe condyle of the left siJe of the lower jaw. 
Fig. 19. I'osterior view of the saiua specimeu as tbe preceding. 
Fig. 20. View of the occipital region. 

Fig. 21. View of the base of a skull. The jaw yet contains on both sides the last two molars nearly 
perfect. 



PLATE XI. 

All the figures are of the natural size. 

Anchithenum Bairdii. 

Fig. 1. View of the left side of a skull, with the zygoma and fore-part of the face broken away. In tbe 
jaw may be observed tbe posterior two molars entire. 

Fig. 2. Upper view of the same specimen as the last. 

Fig. 3. Masticating surfaces of all the right superior molar teeth except the first, which is small, and in 
the specimen is broken away. 

Fig. 4. Outer view of the same specimen as the last. The surface of the teeth is much injured from the 
influence of the weather. 

Fig. 5. Portion of the right side of tbe lower jaw attached to a mass of matrix. It contains tbe posterior 
two molar teeth. 

Fig. 6. Inner view of a portion of the right side of tbe lower jaw containing the posterior five molar teeth. 
From the same specimen as figure 14, Plate X. 

Fig. 7. View of the masticating surfaces of tbe latter-mentioned teeth. 

Fig. S. View of the masticating surfaces of six inferior molars of the left side. 



PLATE XII. 

Figures half the diameter of Nature. 

lihinoccros occidcn talis. 

Fig. 1. View of tbe base of the skull. Tbe left zygoma is preserved nearly entire, and upon tbe same side 
of the jaw all the molars except tbe first, which is, however, whole upon tbe right side. A portion of tbe 
left occipital condyle remains; and in advance of it may be observed the anterior condyloid foramen, tbe 
mastoid process, the post-glenoid process, and tbe glenoid articulation. 

Fig. 2. View of the left side of the skull. The face is much mutilated, but tbe form of the orbit is 
comparatively well preserved. The zygoma is almost entire, and posterior to its root is observed tbe meatus 
auditorius, formed between the post-glenoid and mastoid processes. By the restoration of the first tooth of 
the series, all the molars are exhibited quite perfect. 



PLATE XIII. 

Figs. 1-4. Half the diameter of nature ; the remaining two of the natural size. 

Rhinoceros occiden talis. 

Fig. 1. View of tbe top of the skull, from tbe same specimen as Plate XII. 

Fig. 2. Fragment of the left side of tbe lower jaw containing the last two molars, viewed from without. 

Fig. 3. Fraginont of tbe left side of the lower jaw, containing the three molars anterior to tlie last. 

Fig. 4. View of the triturating surfaces of tbe teeth, from tbe same .specimen as the last. 

Figs. 5, C. Outer view of two inferior, slightly worn, molars of tbe right side. 



124 EXPLANATION OF THE PLATES. 



PLATE XIV. 

Rhinoceros AWtrascensis. 

Figs. 1, '2. Two-thirds tlio diameter of nature. View of the left side of a much mutilated face and lower 
jaw. In the upper jaw are seven molar teeth, the triturating surf;ices of which, from the same specimen, 
are represented of the natural size in Fig. 3, Plate XV. The lower jaw contains six molars entire. 

Fig. 3. The size of nature, represents the triturating surfaces of the teeth last mentioned, from the 
same specimen. 

Figs. 4-8. Different views of superior molars, which had not yet protruded from the jaws, and therefore 
■were entirely unworn. Of the natural size. 

Fig. i. E.^ternal view of the anterior four molars of the left side. 

Fig. 5. View of the triturating surfaces of the same teeth. 

Fig. 6. Internal view of the same teeth. 

Fig. 7. View of the anterior side of the third right superior molar. 

Fig. 8. View of the posterior side of the same specimen as the last. 

Fig. 9. Triturating surfaces of the teeth from the same specimen represented in the succeeding figure. 
Natural size. 

Fig. 10. Fragment of the left side of the lower jaw of a very young animal, viewed upon its outer side 
and exhibiting the last temporary molar and the first succeeding permanent molar. 

Fig. 11. One-half the diameter of nature. View of the forehead taken from the same specimen as 
figure 1. 

Fig. 12. Two-thirds the diameter of nature. View of the inion or occipital region, represented from the 
same specimen as Figs. 1, 2, Plate XV. 

Fig. 13. View of the triturating surfaces of the entire series of the superior molars of the right side, 
from a diifercnt individual from any other indicated. Natural size. 

Fig. 1-t. Fragment of an upper jaw of the right side of a young animal, exhibiting the triturating 
surfaces of the posterior three temporary molars. Natural size. 



PLATE XV. 

Rhinoceros Nehrascemin. 

Figs. 1, 2. Two-thirds the diameter of nature. 

Fig. 1. View of the right side of a skull, with the top broken away its whole length. The specimen 
belonged to a very old individual, as the molar teeth are nearly worn away to the fangs. 

Fig. 2. View of the base of the skull from the same specimen as the last. The characteristic enamelled 
triturating surfiioes of the molars are entirely obliterated. 

Fig. 3. The size of nature. It represents the triturating surfaces of the superior molars of the left side. 



PLATE XVI. 

Titanotherium Proutii. 

Fisrs. 1, 2. One-third the diameter of nature. 

Fig. 1. A portion of the right side of the lower jaw, containing the last two and part of the first molar. 

Fig. 2. A portion of the left side of the lower jaw of a second and smaller individual, containing the 
three true molars and the fangs of that in advance. 

Fig. 3. One-half the diameter of nature. View of the triturating surface of the true molars, from the 
same specimen as figure 2. 

Figs. 4-7. Two-thirds the diameter of nature. 

Figs. 4, 5. Fragment of a left posterior superior molar. Fig. 4. Outer view of the entire portion of the 
fragment. Fig. 5. View of the masticating surface of the same fragment. This last presents the external 
anterior cu.sp with two pits at its base, and the large internal conical lobe. 



EXPLANATION OF THE PLATES. 125 

Figs. 6, 7. Fragment of a superior true molar. Fig. 6. Inner view. Fig. 7. Triturating surface of the 
same specimen, presenting a large conical lobe, with portion of an enamelled pit at the outer side of its 
base. 

Figs. 8-12. The size of nature. 

Figs. 8-10. A second? inferior molar of the left side. Fig. 8. The triturating surface. Fi". 9. The 
outer view. Fig. 10. The inner view, which is a vertical plane. 

Figs. 11, 12. An inferior canine tooth, the size of nature. Fig. 11. Outer view. Fig. 12. Inner view. 



PLATE XVII. 

All the figures of the natural size, except 8-10, which are two-thirds the diameter. 

Figs. 1-10. Ti/anolherium Proulii. 

Figs. 1-3. A superior premolar. Fig. 1. Inner view. Fig. 2. Outer view. Fig. 3. View of the tritu- 
rating surface. 

Fig. 4. View of the triturating surface of another superior premolar. 

Figs. 5, 6. Fragment of a superior premolar. Fig. 5. View of the triturating surface. Fig. 6. Inner 
view. 

Fig. 7. View of the triturating surface of a fragment of a superior premolar. 

Figs. 8-10. A last posterior inferior molar of the left side. Fig. 8. Outer view. Fig. 9. View of the 
triturating surface. Fig. 10. Inner view. 

Figs. J 1-13. Palaeolherium gtijanteum. Views of three fragments of as many superior molar teeth ; 
being single external lobes seen upon their outer face. 



PLATE XVIII. 

Figures of the natural size. 

Machairodus primaevus. » 

Fig. 1. View of the right side of a skull, with the lower jaw. The symphysis of the latter, upper inci- 
sors, and zygoma are broken away. The upper jaw presents a portion of the canine, and the second to the 
last molar inclusive; and in the lower jaw the first and a portion of the second molars are visible. 

Fig. 2. Superior view of the right half of the same specimen as the preceding. 

Fig. 3. View of the left side of the lower jaw, containing the three molars and a portion of the upper 
jaw, exhibiting the second molar, from the same specimen as the preceding. 

Fig. 4. Outer view of the right inferior canine, which was attached to the mass of matrix adhering to the 
preceding specimen. 

Fig. 5. Front or anterior view of the same tooth. 



PLATE XIX. 



Figures two-thirds the diameter of nature. 
Testudo Nebrascensis. 
Fig. 1. Dorsal view of the carapace. 
Fig. 2. Lateral view of the carapace. 
Fig. 3. Inferior view of the sternum. 



17 



126 EXPLANATION OF THE PLATES. 

PLATE XX. 

Figures lialf the diameter of nature. 

Tcsludo hemhpherica. 

Fig. 1. Dorsal view of the carapace. 



Fig. 2. View of the sternum. 



Figures half the diameter of nature. 
Tcstudo Owati. 

Fig. 1. Dorsal view of the carapace. 
Fig. 2. View of the sternum. 



PLATE XXI, 



PLATE XXII. 



Figures one-third the diameter of nature. 
Testudo Culhertsonii. 
Fig. 1. Dorsal view of the carapace. 
Fig. 2. View of the sternum. 



PLATE XXIII. 

Figures one-fourth the diameter of nature. 
Testudo lata. 

Fig. 1. Dorsal view of the carapace. 
Fie. 2. View of the sternum. 

PLATE XXIV. 

Fig. 1. One-fourth the diameter of nature; the remaining figures one-third. 

Fig. 1. View of the left side of the carapace of Testudo lata. 

Fig. 2. View of the left side of the carapace of Testudo Culhertsonii. 

Fig. 3. View of the left side of the carapace of Testudo hcmisphcrica. 

Fig. 4. View of the left side of the carapace of Testudo Owcni. 



PUBLISHED BY THE SMITHSONIAN INSTITUTION, 

WASHINGTON, D. C. 

JUNE, 18.53. 



Plate I. 




A ^onrel on Kloite from tiat 



Printed ky Tappai* 8t Braafora. 



1-4.P0EBR0THERIUM WILSONII, Leidy, 5-10. AGRIOCHOERUS ANTIQUUS , Leidy 



PJate II 




/V Sonrfil on. stone from, nat 



Prinrcd by Twppam, i RrttdfoPtl 



OREODON CULBERTSONII, Leidy. 



Plate III. 




A SorvreL on stone b.om aat 



Printed, ^y Tappan &. Bradford. 



OREODON CULBERTSONII , Leid 



7- 



Plate IV. 




A.Frey Dei. 



TSittclains llth.. Phila.. 



1-b, OREODON GULBERTSONII,Leidj, 
6, ORE ODON MAJOR, Leidy. 



\'l':i,- V 



-»,r,;-.'-'fes; ^i^^^^STCe.;-' 



^^'-^^ 



V 








"fs^U 











A J rbbuLson Dei 



I oifinia.rs Lnh.nila 



1,2, OREO DON GULBERT30NlI,Leidj' 
3,4 OREODON GRACILIS, Leidy. 



Plate VI. 




A J Ibbotson Del 



T Sinclairs Lith Phila 



1 7 OREODON GRACILIS, Leidy. 

8-11 OREODON CULBERTSONIl, Leidj, 



Plate Vn 







■-iJ#^ 



f 




ATrey Del 



T.SincIairs Lith.Phila: 



1-3, EUGROTAPHUS AURITUS, Leidj. 
4-6, EUGROTAPHUS JACKS ONI , Leidj. 




ARCHAEOTHERIUM MORTON! , Leidy 



Plate IX. 




^^v 







k Som-fl .S-omttR 



Printed bv Tappan. 'i- SradFord. 



ARCHAEOTHERIUM MORTONI . Leidv 



Plate X. 




n-orrLTLaf. cins;Qn 



Prii'.ted by Tappa.^. S' Braiford. 



ARCHAEOTHERIUM MORTONI, Leidy . 8-13, A.ROBUSTUM. Leuly. 
14-21, ANCHITHERIUM BAIRDII , Leidy 



Place XI 








5. 



■^ ' 




n^_j[^ 









A.Sonrel onstone from, na 



Printed b-y TapoaTvA. B-radFord. 



ANCHITHERIUM BAIRDII , Leidy . 



Plate XII. 




A.J,lbbotsonDel 



'T.SiacIairs lith.Phiia- 



RHINOCEROS OGGIDENTALIS, Leidy. 



Plate XIII. 




A.Frey.Del 



T Sinolairs Lith.FHla.. 



RHINOCEROS OCGIDENTALIS, Leidj. 



Plate ZIV, 




A Frey Del 



T, Sinclair's lith. Phila 



RHINOCEROS NEBRASGENSIS Leid 



y 



Plate XV. 











Soiire"! or, storve ttonx nat. 



Printed by Tappan a-BradEord 



RHINOCEROS NEBRASCENSIS , Leicly. 



Plate XVI 




XSinclair! lith-fhila. 



TITANOTHERIUM PROUTII, Leidj. 



Plate IVII. 




I Butler Del 



T.Smclair'B Lith.Phila 



i-10 TITMOTHERIUM PROUTlI.Leidj. 
11-13 PALAEOTHERIUM GIGANTEUM^Leidj. 



Plate. XVIII 




f.richcn. Doi. 



T Sinoiairs lith Phila. 



MAGllAIHODUS PRTMAT'iYI.kS, Loidy and Owen. 



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