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UNGULATA. {Hoofed Mammals.) 
This group includes the following suborders represented in the 
collection by fossil forms : 
Perissodactyla. . ..odd-toed ungulates, as Horse, Tapir, Rhinoceros, &c. 
Artiodactyla even-toed ungulates, as Deer, Sheep, Ox, &c. 
Proboscidia Elephant, Mastodon, &c. 
Amblypoda heavy-footed ungulates, as Dinoceras, Coryphodon, &c. 
Condylarthra . . . .primitive ungulates, as Phenacodus (see cast in hallway). 
Condylarthra {primitive ungulates). — This suborder is 
represented by a cast of Phetiacodus primavus Cope, presented by 
Dr. Robert H. Lamborn, in the hallway at the north end of the 
room. It was of about the size of a Sheep, but possessed five 
complete toes on each foot. It pertains to the Eocene period. 
There are also jaws, teeth and feet in the case of vertebrates in 
the body of the room. 
Amblypoda. — Remains of a very ancient and remarkable form 
called Coryphodon, from its yoked-shaped teeth, are shown in 
the large case. It resembled the Bear in its walk, but the limbs, 
although short, were as heavy as those of the Rhinoceros. Of 
one skeleton there are shown the complete fore and hind feet, the 
limbs and pelvis. Also many of the teeth of different individuals. 
Perissodactyla {odd-toed ungulates). — These forms are 
characterized by the middle toe being larger than the others, like 
the Horse, whereas the outer toes are nearly obsolete. Among 
the earliest to appear were the ancestral tapirs {Systemodons), 
see specimens in large case* There are also shown the lower jaws 
of the earliest of the Horses {Hyracotherium), and a restoration 
of a complete five-toed Horse {H. venticolum) no larger than a 
Fox. The later horses are also represented by the teeth and skulls 
of Mesohippus from the Miocene of the Judith River (Case q, 
Sect. 6), which is intermediate in its characters between Hyra- 
cotherium and the modern Horse. There is also, in the large case, 
the fore foot of Palseosyops, an ancestor of the great Titanotherium 
{-Menodus) and in Case Q, Sects. 6 and 7, jaws, teeth and 
many separate bones of the skeleton. A group of hornless 
Rhinoceroses is represented by jaws and teeth of Aceratherium, 
and jaws, skulls and limb bones of Hyracodon, in Sects. 4, 5 and 
6 of Case q. • 
* Many of these Mammalia are placed temporarily in the front of Case S. 
