RHIAVCERO TID.K 



411 



sented in the Pleistocene of Southern India by the small 11. clcccan- 

 ensis and /«'. ka/rnvMensis. 



In the Upper Miocene, or Lower Pliocene, of North America 

 numerous Rhinoceroses with incisor teeth occur which have no 

 nasal horn, although in those forms of which the limbs are known 

 the fore feet resembled those of existing species in having only three 

 digits. These species have been generically separated as Aphelops, 

 bul so closely do they resemble existing Rhinoceroses that atone 

 time Professor Cope proposed to refer the hornless female of II 

 sondaicus (described by Lesson as R inermis) to the same genus. 

 If these American types be included in Rhinoceros there seems no 

 valid reason for separating the European Lower Pliocene and Mio- 

 cene forms described as Aceratherium, at least some of which have 



Fig. 173.— Skull of Rhinoceros leptorhinus, from the Pleistocene of Essex. About J natural size. 



four digits in the manus. This group is represented in the Upper 

 Eocene Phosphorites of France, and also by a very large species in 

 the Pliocene of India. Lastly, B. minutus, of the Lower Miocene of 

 France, and an allied North American species are distinguished by 

 carrying a pair of very small horns placed transversely across the 

 nasals, from which feature it has been proposed that they should 

 be separated generically as Dicer either htm. 



Extinct Generic Types. — The Tertiary deposits of different parts 

 of the world have yielded remains of many extinct forms more or 

 less closely related to the Rhinoceroses, and some of which should 

 certainly be included in the same family; although others perhaps 

 form the types of one or more distinct families. One of the most 

 remarkable of these extinct types is the huge Elasmotherium, from 

 the Pleistocene of Siberia, in which the dentition was reduced to 

 two premolars and three molars on either side of each jaw. The 



