=] 
bo 
TITANOTHERIUM. 
Fam. 2.— IMpPaARIpiGITATA ORDINARIA. 
TETANOTHERIUM, Lery. 
Vitanotherium Prowtii, Levy. 
(Prats XVI. XVIL., Figs. 1-10.) 
Palacotherium, Prout: Am. Journ. Sci. Arts, 1847, iii., 248, figs. 1, 2. 
Palaeothertum ? Proutii, Owen, Norwood, and Evans: Proc. Acad. Nat. Sci., 1850, v., 66; Leidy: Ib., 122; 
Owen’s Rep. of a Geol. Surv. of Wise., etc., 551. 
vhinoceros Americanus? Leidy: Ib., 1852, vi., 2. 
In the American Journal of Science and Arts for 1847, page 248, Dr. Hiram AL 
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 Puleotheriwm. 
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 Pulwo- 
therium, 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 Pulaeotherium magnum it 
was 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 of 
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 Pulacothe- 
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 antero-posteriorly, and does 
not possess the slightest trace of a basal ridge such as exists in the true 
Palaeotherium. 
