354 GEOLOGICAL SURVEY OF THE TERRITORIES. 



LEPTOCHCERTJS. 



Another extinct genus thus named is also allied to the peccaries. 

 It is indicated by fragments of jaws and teeth found in association with 

 those of the preceding animal. 



Leptochcerus spectabilis. — This species was about the size of the collared 

 peccary. 



NANOHYUS 



Is the name applied to another extinct genus of suilline animals, indi- 

 cated by a lower -jaw fragment, from the same locality as the remains 

 of the preceding two genera. 



Nanohyus porcinus. — The species was about the size of the common 

 rabbit. 



MICROSUS. 



A small suilline animal of an extinct genus, thus named, is inferred 

 from a jaw fragment with teeth, obtained during the last expedition of 

 Professor Hayden, on Black's Fork of Green Biver, near Fort Bridger, 

 Wyoming. 



Microsus cuspidatus. — The species named from the pointed condition 

 of the tubercles of the teeth was about the size of the common rabbit. 



HYOPSODUS. 



A fragment of the lower jaw with teeth, found in association with the 

 specimen last mentioned, appears to indicate a hitherto unknown genus 

 to which the above name is given. 



Hyopsodus paulus. — The species was about the size of a large hare. 



Anoplotheridw. 



This ancient and extinct family is typified by the singular genus Ano- 

 plotlierium, originally described by Ouvier, from remains obtained from 

 the eocene formation of the Paris basin. In the earliest part of the 

 tertiary period it appears to have been the genus w r hich most nearly 

 approached in character the ruminants of later epochs. In Anoplothe- 

 rium the teeth formed closed series in both jaws, as we now observe to 

 be the case in no mammals except man. 



TITANOTHERIUM. 



This genus is apparently allied to the Anoplotherium of Europe, and 

 another extinct genus named Ghalicotherium, whose remains were dis- 

 covered in the Sevalik Hills of India. 



Titanotherium prouti. — This species is established on remains of a huge 

 animal, the largest of those yet indicated by the fossils obtained in the 

 mauvaises terres of White Eiver, Dakota. It approached in size the ele- 

 phant, and it was no doubt the conspicuous size of its remains which led 

 to its having been the first noticed of all the extinct animals whose bones 

 have been collected in the mauvaises terres cemetery. 



The first notice of it was published in 1846, by the late Dr. Hiram A. 

 Prout, of St. Louis, who, from the character of the lower teeth, supposed 

 it to belong to the genus Palwotherium, originally established by Ouvier 

 from remains obtained from the eocene formation of Paris, France. 



