RHINOCEROTIDE 411 
sented in the Pleistocene of Southern India by the small Lt. deccan- 
ensis and f. karnuliensis. 
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, 
but so closely do they resemble existing Rhinoceroses that at one 
time Professor Cope proposed to refer the hornless female of FR. 
sondaicus (described by Lesson as F. inermis) to the same genus. 
If these American types be included in hinoceros there seems no 
valid reason for separating the European Lower Pliocene and Mio- 
cene forms described as Aceratherium, at least some of which have 
Fia. 173.—Skull of Rhinoceros leptorhinus, from the Pleistocene of Essex. About } 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, R. 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 Diceratherium. 
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 Elasmotheriuwm, from 
the Pleistocene of Siberia, in which the dentition was reduced to 
two premolars and three molars on either side of each jaw. The 
