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MANUAL OF ZOOLOGY. 



nasal bones. This singular form further differs from the typical 

 Rhinoceroses in having four toes to the fore-feet, whilst the 

 hind-feet have only three. 



The development of the nasal bones in the Rhinoceroses 

 varies greatly in accordance with the varying condition of the 

 horns. In the extinct Acerotherium, in which there are no 

 horns, the nasal bones are greatly reduced in size. In the 

 horned forms, on the other hand, not only are the nasal bones 

 prolonged forwards over the nasal cavity; but the septum 

 narium may be partially or completely ossified, thus strength- 

 ening the basement of the anterior horn in the bicorn species. 



Fig. 391. A, Side-view of the skull of Tapirus A mericanus ; B, Side-view of the 

 skull of Rhinoceros bicornis. (After Giebel.) 



The Rhinoceroses live in marshy places, and subsist chiefly 

 on the foliage of trees. They are exclusively confined at the 

 present day to the warmer parts of the Old World; but several 

 extinct species formerly ranged over the greater part of Europe. 

 Of the one-horned species, of which there are three, the best 

 known is the Indian Rhinoceros (R. Indicus or umcornis), 

 which was probably the " Unicorn " of the ancients. Another 



