592 UNGULATES. 



size, are more divergent, and directed more upwards ; they have 

 been found of the length of from eight to ten inches, of which the 

 implanted base measured three-fifths of the entire length of the 

 tooth, and the crown was one inch and a quarter in breadth ; this is 

 worn obliquely inwards at its upper enamelled part. 



Not a trace of a canine tooth or its alveolus has been observed 

 in the skull of a mature individual of any existing or extinct species 

 of Rhinoceros, but such we must consider the small and simple tooth 

 (PI. 138, fig. 13, c) developed at the fore part of the superior 

 maxillary bone in the fcetal Rhinoceros indicus, two lines in advance 

 of the alveolus of the first small deciduous molar (p 1) and one 

 line behind the suture which unites the maxillary with the inter- 

 maxillary bone. The specimen in which I detected this tooth, the 

 crown of which had pushed through the jaw, but not through the 

 gum, appeared to be at the full-time, or newly born. The tooth 

 and its socket must soon disappear, for in the specimen of the 

 upper jaw of a young Indian Rhinoceros figured by Cuvier in the 

 ' Ossemens Fossiles,' torn. cit. PI. v, fig. 3, there is no trace of 

 the alveolus of the rudimental canine in the tract of bone between 

 the first deciduous molar and the intermaxillary suture; anterior 

 to this the intermaxillary bone shows the sockets of the two com- 

 paratively large incisive teeth. This discovery of vestiges of 

 canines in the genus Rhinoceros shows an additional character, 

 although a transitory one, linking that genus with the nearly allied 

 extinct Palseotherium. 



The first of the permanent series of seven molar teeth is very 

 small in both jaws, and is soon shed. The first upper premolar 

 is notched on the inner side in the one-horned Rhinoceros 

 (PL 138, fig. S, p \) ; the notch sinks deeper and expands 

 in the African two-horned species ; and in the Sumatran bicorn 

 Rhinoceros it presents a detached lobe on the inner side : the second 

 upper premolar is more suddenly enlarged in the one-horned than 

 in the two-horned Rhinoceros. Before the crowns of these large 

 and complex premolars and molars begin to be abraded, the 

 eminences bounding the valleys terminate in sharp enamelled ridges, 

 the principal extending along the outer border of the grinding 



