342 



RHINOCEROS. 



more developed and more nearly of the size of the posterior 

 horn, in R. hemitcechus than in R. megarhinus. 



As regards the first of these characters, the penultimate and 

 last premolars in the latter species are nearly of equal size ; 

 while in R. h&mitoechus there is a progressive increase in 

 length of crown from the antepenultimate to the last. The 

 difference is shown by the subjoined comparative measure- 

 ments. 



The second character is well exhibited, on comparing 

 fig. 8 of PI. II. of Gervais' ' Paleontologie ' with PI. XIX., 

 annexed. In the former the anterior horn of the crescent, 

 in p.m. 3 and 4, and in m. 2 and 3, forms an insignificant 

 lobe, indicated by the anterior niche on the inner side of 

 each of these teeth ; while in p.m. 3 and 4, and in m. 2 and 

 m. 3 of PI. XIX. of R. hemitcechus the anterior horn of the 

 crescent makes as large a sweep as the posterior horn. The 



