FOSSIL MAMMALS OF THE ORDER DINOCERATA. 147 
These animals nearly equalled the elephant in size, and had limb 
bones resembling those of Proboscidians, as stated in the original 
description of the type species, Tinoceras anceps Marsh. The 
skull, however, presents a most remarkable combination of char- 
acters. It is long and narrow, ahd supported three separate pairs 
of horns: The top of the skull is concave, and on its lateral and 
posterior margin there is an elevated crest. There were large de- 
curved canine tusks, somewhat resembling those of the walrus, but 
no upper incisors. The six premolar and molar teeth are quite 
anceps.* In the following year Professor Cope gave the name, 
Loxolophodon semicinctus, to a single premolar tooth, which per- 
haps, belongs to this group, and may prove to be identical with 
the above species.t In August last, in a paper issued in advance 
of the Proceedings of the Philadelphia Academy, Dr. Leidy de- 
scribed a characteristic specimen as Uintatherium robustum, and 
likewise gave the name Uintamastix atrox to an upper canine tooth, 
probably of the same animal, on the supposition that it pertained 
to a carnivore.} | 
The remarkable feature in the skull of this group was first in- 
dicated in the name Tinoceras, proposed by the writer (August 
19, 1872) for the genus represented by the type species, and sub- 
sequently mentioned in the American Journal of Science.§ 
The Museum of Yale College contains the remains of many in- 
dividuals of the order Dinocerata, including the types of the 
Various species described by the writer.|| All of these are well 
represented by characteristic specimens, and one species, Dinoceras 
mirabilis Marsh, by an gutire skull, and a nearly perfect skeleton. — 
An Opportunity has thus been afforded of determining with some 
: * American Journal of Science, Vol. ii, p. 35. 
t American Philosophical Soc., Vol. xii, p. 420. 
eedings Philadelphia Academy, 1872, p. 169. 
SVol. iv, September, 1872, Erratum; also October, 1872, p. 322. aa 
ll American Journal of Science, yol. iv, pp. 322, 323, 343. Oct., rae att ee paea 
American Philosophical Society, vol. xii, p. 578, Dec., 1872, and Ameri = 
Vol. vii, p. 52, Jan., 1873. i < : 
