HISTORY OF THE PERISSODACTYLA 329 



and twigs, and they frequent forests and marshes where their 

 food is abundant. Not that these and other browsing animals 

 do not occasionally eat grass, but it is not their principal diet. 

 The exception noted is the largest of all the living species, the 

 Broad-Lipped Rhinoceros (erroneously called "White") of 

 Africa, Opsiceros simus, which is strictly a grazing animal and 

 therefore frequents more open country than the other African 

 species, 0. hicornis. 



There are considerable differences in proportions and 

 general appearance among the various species, but they all 

 have short necks, very long and massive bodies, short and heavy 

 limbs and short, columnar feet, which look much like those 

 of elephants, but have only three toes each. In all but two 

 of the living species the upper lip is prehensile and characteristi- 

 cally pointed and can be used to pick up very small objects, 

 like the ''finger" on an elephant's trunk; in the Sumatran 

 species (Dicerorhinus sumatrensis) the lip, though pointed, is 

 horny and inflexible, while in the African 0. simus it is broad 

 and straight-edged. 



The teeth of the modern rhinoceroses are extremely char- 

 acteristic and may always be recognized at a glance. In the 

 African genus {Opsiceros) there are no front teeth, all the incisors 

 and canines being lost ; the other genera have on each side 

 a single large and trenchant upper incisor, in shape like a broad, 

 obliquely edged chisel, which shears against a still larger 

 elongate and tusk-like lower incisor, that is procumbent and 

 points directly forward. The Indian Rhinoceros {R. unicornis) 

 is said to use its tusks as weapons in very much the same fashion 

 as the Wild Boar. Between the large lower tusks there is a 

 pair of very small incisors, which can have little or no functional 

 value ; the third lower incisor has been suppressed, as have also 

 the canines of both jaws. The dental formula then is : i I or ^, 

 ct pi, m|, X2 = 28 or 34 (see p. 93). The premolars, 

 except the first, though somewhat smaller than the molars, 

 have essentially the same pattern. The upper molars have 



