290 
POPULAR SCIENCE REVIEW. 
which possessed them, and have been formidable weapons in 
encounters either with animals of its own kind, or with the 
carnivorous beasts whose remains have been found associated 
with it. 
The teeth were no less remarkable than the general formation 
• 01 3 3 
of the skull. The dental formula was i c v m - = 34. 
3 1’ 1 3’ 3 
The front teeth, or incisors, were, as in modern ruminants, 
absent above, and in the lower jaw rather small, directed for- 
wards, and forming a continuous series with the still smaller 
canine. A large, trenchant, enamel-covered tusk, not unlike 
that of the musk-deer, or Chinese water-deer ( Hydopotes ), 
descended from each side of the upper jaw, and lay against a 
singular flattened expansion of the lower border of the ramus 
of the lower jaw, which has been conjectured to be for the 
purpose of protecting them from injury, though no such pro- 
cesses are found necessary in the animals above mentioned with 
similar tusks ; and they recall a like conformation of the 
Megatherium , which can have no such function. They must 
have effectually prevented any stabbing or penetrating action 
of these weapons. There is some evidence that the tusks were 
smaller in the females. The molar teeth were six on each side, 
above and below, placed in continuous series, and separated 
from the canines by a considerable interval. They were small 
for the size of the animal, and of simple structure, each having 
two more or less transverse crests, though those of the upper 
jaw diverge externally, and meet at the inner border of the 
tooth in a V-shaped manner. 
The brain (as indicated by the size and form of the cerebral 
cavity, of which a cast has been made and figured by Professor 
Marsh) was proportionately smaller than in any other known 
mammal, recent or fossil, and was almost reptilian in its 
character. (See PI. CXXXVIII. fig. 3.) It was actually so 
diminutive (in Marsh’s Dinoceras mirabile) that the entire 
brain could apparently have been drawn through the neural 
canal of all the presacral vertebrae, certainly through the cer- 
vicals and lumbars. It was therefore exceedingly unlike that 
of modern Proboscideans. 
These animals, taking the totality of their organisation into 
consideration, appear to belong to the great Ungulated group, 
and to hold a position somewhat intermediate to the Perisso- 
dactyles and the Proboscidea, though nearer to the former 
than was at first supposed. This affinity is still further shown 
by the discovery of other forms, constituting the genera Bath- 
modon and Metalophodon of Cope, from an earlier geological 
horizon, which, with the general structure of the Uintatheridce, 
retain, in an extremely interesting manner, many primitive 
