RRINOCEROS. 177 



being about three-fourths the size of the Rh. Indicus, that is, about the size of Cuvier's Eti. mixutus, 

 which is regarded bj' De Bhiinville as a small variety of the Eh. incisivus. The other was less than 

 two-thirds the size of tlie former species, and is much the smallest Ehinocoros which has yet been 

 discovered. 



I have adojpted the division of the genus into two groups (which jn'ove respectively African 

 and Asiatic), according to their possessing or not possessing permanent incisors in the upper 

 jaw. The reader may wisli to know how this applies to extinct species, and more especially to the 

 new-found American ones. No particular inferences can be drawn from this character as regards 

 them, for at the epoch when they existed (the tipper eocene or lower miocene), all the species 

 of Ehinoceros appear to have had incisors in the upper jaw, and so had the Nebraska species. It is 

 only when we come to more recent times, to the period of the drift and diluvium, when the woolly- 

 haired Ehinoceros (Eh. tichokhimus) flourished, that the type now peculiar to Africa begins to 

 appear. The Eh. tichorhinus belongs to it, as well as numerous so-called species of the same 

 epoch, and found over the same ground, which probably are only varieties or individuals of that 

 species. 



No remains of any species have been fouiid in America in deposits subsequent to the glacial 

 epoch. 



A remarkable extinct animal, the Elasmotherium of Fischer (E. Fischeri, Meyer), shoidd 

 be here noticed. It is placed by Cuvier between the Horse and the Ehinoceros, and has been 

 found in the Siberian drift. The lower jaw was two feet in length, and four inches high. 



