GEOLOGICAL SURVEY OF THE TERRITORIES. 355 



Many remains, consisting of fragments of jaws, teeth, and articular ends 

 of different bones of the skeleton, collected by Messrs. Meek, Hayden, 

 and Evans, indicate a nearer alliance of the animal to the companion of 

 the Palceothere, that is to say, the Anoplothere. 



The remains of the species, named in honor of its discoverer, Dr. Prout, 

 belong to the lowest beds of the miocene deposits of the mauvaises terres, 

 according to the authority of Professor Hayden. 



The teeth of Prout's Titanothere formed nearly unbroken rows, though 

 not so completely! as in the Anopothere. It appears to have possessed 

 an incisor less on each side tban in the latter, and it's canines were pro- 

 portionately larger, differences which induced small breaks or intervals 

 in the dental series. Among living animals, the grinding teeth of 

 the Titanothere approached most nearly in appearance those of the rhi- 

 noceros. In the best preserved specimen of the jaws of Titanothere the 

 series of teeth measure nearly a foot and a half in length. 



Various fragments of the skeletons of different individuals indicate 

 considerable variation in size, probably due to difference in sex. 



Dr. John Evans reported the discovery of the skeleton of an individ- 

 ual imbedded in. the rock in the mauvaises terres, which measured, in 

 position, about eighteen feet in length and nine feet in height. This 

 appears much too large in proportion to the size of the jaws above 

 referred to, and the measurement is probably greatly exaggerated, if it, 

 perhaps, does not apply # to some other and larger animal. The speci- 

 mens upon which the species T. Prouti is established indicate an animal 

 intermediate in size to the Indian rhinoceros and the elephant. 



PAL^OSYOPS. 



This extinct genus is indicated by some remains obtained during Pro- 

 fessor Hayden's last expedition. The specimens consisting of small 

 fragments of jaws, with molar teeth, were found at Church Buttes, and 

 on Henry's Fork of Green Biver, Wyoming. The remains belong to the 

 Bridger Group of tertiary rocks, probably of miocene age. The genus 

 is closely allied to Titanotlierium of the mauvaises terres, and to Chal- 

 icotherium of the Sevalik Hills of India. 



Palwosyops paludosus. — The only species of the genus approximated in 

 size the common ox. 



Anthracotlieridce. 



This name has been given to an extinct family of even-toed pachy- 

 derms whose types are the genera AntJiracotlierium and Cheer vpotamus, 

 of the early and medial tertiary formations of Europe. It is also rep- 

 resented in the miocene tertiary formation of the mauvaises terres of 

 White Biver by the remains of a genus which had been previously 

 recognized as occurring in England and Erance. 



HYOPOTAMUS. 



This genus was established by Professor Owen from some remains 

 found in the eocene deposit of the Isle of Wight. The true molar teeth, 

 or grinders, resemble those of ruminating animals, except that the upper 

 ones present the remarkable character of an additional or fifth lobe- 

 introduced between the anterior pair of lobes. The whole number of 

 teeth and the kind correspond with those of the existing hog. 



Hyopotamus Amcricanus. — A species based upon fragments of jaws and 



