Unoulata. MAMMALIA. — — Ungulata. 
the form of terraces or table-lands, consisting of 
nearly horizontal strata, variously colored indurated 
clays and sandstones. 'J'hrough atmospheric agencies 
the beds are worn away, and the embedded fossils 
fall with the crumbling masses, llr. Leidy says, in 
viewing the vast piles of broken terraces that com- 
pose the •* Bad Lands •• 'I'he utter desolation of the 
scene, the dried-up water courses, the absence of any 
moving thing-, and the profound silence • which pre- 
vailed, })roduced a feeling that was positively oppres- 
sive. When 1 thought of the ‘buttes’ beneath my 
feet, with their entombed remains of multitudes of 
animals, forever extinct, and reflected upon the time 
when the country teemed with life, I truly felt that 
I was standing on the wreck of a former world.” 
'I’his region has already become classic ground to 
the paleontologist. 
Thk EquiDjE are here represented by six species of 
Horses, and one of llipparion. In the Tertiary, Blio- 
hippus and Protohippus are known. 'I’liese all have 
the lateral toes developed, but they are not service- 
able. Anchippus, Merychippus and Hyohippus are 
related to the European Hippotherimn. These are 
very small, being only about two and a half feet 
high. 
ANCHiTHERiDyE is the name of a family of extinct 
forms, resembling the Horse. The lateral toes in 
these are so developed that they are used in locomo- 
tion. Anchitherimn, as previously recorded, is 
found in Europe, as well as in America. A species 
is named A. bairdi. Four others are enumerated. 
The extinct genera Miohippus and Mesohippus em- 
brace certain Horse-like animals, about the size of a 
Sheep, each having three toes on each foot. Several 
species, about the size of a Fox, have been found in 
the Eocene of Utah and Wyoming. These have four 
toes before, and three behind. 'I'he last-mentioned 
are included in the genus Orohippus. 
Falwosyops is an allied form, belonging to the 
same family as the preceding, represented in the 
Eocene of Wyoming by four species. Lymnohyus 
has one species. Hyrachyus is an extinct genus of 
odd-toed Pachyderms, found in the same locality ; it 
is closely related to the tapiroid genus Lophiodon ; 
also, in a less degree, with the Rhinoceros-like Hy- 
racodon. Several species are known in the Eocene. 
Lophiotherium is an extinct genus of tapiroid Pachy- 
derms, closely allied to Lophiodon. A form of odd- 
toed Pachyderm, which is regarded as very curious, 
is 'I’l-ogosus, an extinct genus ; it was about the size 
of a living Peccary. It had no canines, and was pro- 
vided with a large pair of incisors, like those of a 
Rodent. It is called T. castoroidens, or the '* Beaver- 
toothed Gina wing-hog.” 
Hyopsodys is an extinct genus, including the 
smallest of Pachyderms ; and Microsyops is another 
ot the same size. Elotherium has three species ; and 
Dicotyles is represented by one species. 
CameliDjE, embracing the Camels, is one of the 
most numerous families on the American continent, 
in so lar as relates to extinct genera and species. 
'I’he genera Auchenia and Procamelus, the latter 
with several species, are known. An extinct genus 
VOL. l.—P 
cxiii 
— Palauchenia — found in Mexico, was about the size 
of the living Camel of the Old World. The species 
Auchenia califoVnica exceeded it in size. 'I'he extinct 
genus Procamelus was found in the Miocene of Vir- 
ginia. Megalomery.x is an extinct genus, allied to 
the preceding. Homocainelus is from the Pliocene. 
In the Miocene are found the extinct genera Poebro- 
therium and Protomeiyx, the former allied both to 
Camel and Llama. 
Bovid^ are represented by Bison latifrons, and 
three others, in the Quarternary of California and 
Pennsylvania, and in other (Southern) States; and by 
an extinct genus — Casoryx — which is thought to be 
intermediate between the Antelope and Deer. 'I'he 
Musk Ox — Ovibos — is represented by an extinct 
species in the Diluvium. 
Cervidzs. — 'I'lie Deer have representatives in the 
extinct genera Leptomeryx and Merycodus ; the lat- 
ter resembling the Camels, as well as Deer. The 
extinct genera Hypisodus and Hypertragulus, very 
small individuals, are allied to 'I’ragulus and Le[)- 
tonieryx. Several extinct species of Cervus are also 
found in the same deposits — the Miocene of Wyoming. 
Capridze are seen in the Pliocene. One extinct 
species — the mammilaris — is known. 
LiMNOHYiDAi:. — -'I'his is a family of animals, about 
the size of Sheep. Limnohyus is the type, and 
Colonoceras is of the family. 'I’he nose of these 
forms had horny protuberances on the upper surface. 
'I'he wonderful genus Bathmodou, five species of 
which have been described, from the Eocene of New 
Mexico, is regarded as forming the type of a new 
family. 
RHiNocERoriDZE. — -'I'liis family was represented in 
these ancient times by Rhinoceros in the Pliocene 
and Miocene, and by Aceratherium aiid Hyracodon 
in the Miocene. In the Eocene and Miocene of 
Utah and Oregon, several wonderful extinct Rhino- 
ceroses have lately been found ; they form the genus 
Diceratherium. 'I’here were two horns on the snout, 
side by side. 'I'hey were not so large as the living 
forms. Allied to these was the extinct family 
Brontotheridze. — C ertain of these forms exceeded 
in bulk the largest living Rhinoceros. Dr. Leidy and 
Prof. Marsh describe the extinct genera Brontothe- 
rium, 'I’itanotherium and Megacerops and Anisacodou. 
Another remarkable genus is Symborodon, from the 
Miocene of Colorado ; it has seven species, one of 
them having nearly the bulk of an Elephant. 'I’he 
latter is thought to have had a proboscis. Peccaries 
are fouinl in the Pliocene of Nebraska and Oregon ; 
and an allied form, called 'I’hinohyus. 'I’he Miocene 
exhibits allied genera Nanohyus, Leptochcerus and 
Perchoerus. 
Anthracotherid^, a family which connects the 
ruminants with the Hippopotamus, and which is known 
in the Miocene of Europe, is represented in America 
by Hyopotamus in the Miocene of Dakota, and by 
Elotherium in the Miocene of Oregon and the Eocene 
of Wyoming. 'I’he latter has lately been placed, by 
Prof. Marsh, in the extinct order Tillodontia. 
Limnotherid^. — In the Eocene of New Mexico 
are several genera of extinct forms, allied to the 
