288 THE GEOGRAPHY OF MAMMALS 



Black Rhinoceros (R. africanus) extends from the Cape 

 all up the Eastern side of Africa into the plains of the 

 Atbara and Upper Nile. 



The Oriental Rhinoceroses are three in number. Two 

 of these have only one horn on the nose, while the third 

 is provided with two of these appendages. Of the former 

 the large Indian Rhinoceros (R. unicornis) appears to be 

 confined to the North-eastern provinces of the Indian 

 Peninsula, whilst the smaller one -horned form (R. 

 sondaicus) ranges from the Sunderbunds of Bengal 

 through the Malay Peninsula down to Java, Sumatra, and 

 perhaps Borneo. The third Oriental species, the Sumatran 

 Rhinoceros (R. sumatrensis), has nearly the same range 

 as the last-named species, but appears to extend rather 

 farther north. Thus we may consider the existing 

 Rhinoceroses as typical forms of the Ethiopian and 

 Oriental Regions, but not to be met with in any other 

 part of the world's surface. 



Section V. — Distribution of Tapirs 



The second family of Perissodactyle Ungulates, the 

 Tapirs, has a still more remarkable distribution. Out of 

 the five known species four belong to the Neotropical 

 Region, while the fifth, which in some respects is more 

 closely allied to one of the American Tapirs than the 

 American Tapirs are to one another, is an inhabitant of the 

 Oriental Region, being met with only in the Malay 

 Peninsula and Sumatra. This is a good instance of the rare 

 phenomenon of "discontinuous distribution" which, how- 

 ever, may be explained by the fact known from geology 



