270 BRITISH MAMMALS 



which there are two species, the '* white," or square-Hpped, and 

 the black, or pointed-Hpped. Neither of these rhinoceroses has 

 any incisor or canine teeth, at any rate functional, though in the 

 jaws of the immature young traces of incisors sometimes appear. 

 This type of rhinoceros has recently been erected into a special 

 genus, DiceroSy because of its marked differences from the Asiatic 

 rhinoceroses. 



The existing Asiatic rhinoceroses also fall into two groups, 

 possibly of generic value. The first is the original rhinoceros, 

 which was first described by scientific men — Rhinoceros indicus, the 

 one-horned, absolutely hairless rhinoceros of India, in which the 

 hide thickens into great ridges and folds, curiously simulating 

 armour. This curious feature of the excessive thickening and 

 folding of the skin is common to the one-horned and two-horned 

 Asiatic rhinoceroses, as is also the retention of functional incisor 

 teeth. But the rhinoceroses of Eastern India and Malaysia differ 

 from Rhinoceros indicus, and from its Javanese ally, in having two 

 horns, and in some anatomical features they possess a certain 

 affinity to the African types, though on the whole they are most 

 nearly related to Rhinoceros indicus on account of retaining the 

 incisor teeth. The two-horned Asiatic rhinoceroses are some- 

 times classed as a separate genus. 



At the close of the Pliocene Epoch there were probably 

 two, if not more, rhinoceroses in England, the remains of which 

 are found in the red crag formations of East Anglia. One of 

 these, Aceratherium incisivum^ was hornless, while the other, 

 which carried two horns {Rhinoceros dihoplus)^ is somewhat allied 

 to the living two-horned Sumatran rhinoceros ; but it is doubtful 

 whether either of these existed in Britain coincidently with 

 man. At the end of the Pliocene and during the earlier part of 

 the Pleistocene Epochs there appeared in England (coming 

 from France) the Leptorhine and the big-nosed rhinoceroses 

 {Ctxlodonta^ or Diceros, etruscus or leptorhinus, and Diceros 

 megarhinus). Both of these, especially the last-named, were 

 closely related to the pointed-lipped African rhinoceros of 

 to-day (Diceros bicornis) ; indeed, it is possible that the 



