Dr. J. E.Gray on the Dentition of Rhinoceroses. 359 



lower jaw is comparatively thin, expanded, and has neither 

 teeth nor alveoli, nor, indeed, one may say, sufficient thickness 

 to hold the larsfe cutting-teeth usually found in the front of the 

 lower jaw of this genus. The grinders are six on each side ; 

 that is to say, the front tooth on each side is retained, whereas 

 it is shed from the skull of the adult but much less aged ani- 

 mal of C. sumatranus in the British Museum ; and the grinders 

 appear to differ in the form of their folds from those of the 

 Sumatran species. 



C. niger, C. sumatranw. 



Length from tip of nose to occipital condyle in. in. 



of adult 21i 22 



From front of intermaxillary to occipital 



condyle 20| 21 



From front edge to back edge of lower jaw . 16^ 17 



AVidth at zygomatic arch 12 11 



Width of hinder end of lower jaw 10| 9| 



Width of upper part of lower jaw at end 



of tooth-hne 7| 6| 



Height of back of skull 13 13^ 



It is very probable that the want of front teeth in the 

 lower jaw may be an individual peculiarity produced by the 

 age of the specimen ; at least I do not think it safe to regard 

 that peculiarity as specific without an examination of more 

 specimens. 



CeratorMnus Crossii. 



In the ' Annals and Magazine of Natural History,' 1872, 

 X. p. 209, I referred to this species and thought it might be 

 the same as li. sumatranus from Tavoy and Tenasserim, 

 mentioned by Blytli, Journ. Asiat. Soc. Bengal, 1862, p. 156, 

 who figures the skull and horns, and who identifies his animal 

 with my R. Crossii (which was described from a pair of horns, 

 P. Z. S. 1854), and has just informed me that he is certain 

 that it is the head of the small black rhinoceros with two 

 horns. 



It is most likely that he is correct in thinking that the horn 

 I figured as R. Crossii is of the same species as the skulls which 

 he received from Tenasserim ; but it is to be observed that I 

 have never seen a skull of the Tenasserim Rhinoceros, and do 

 not know whether it is the same as C. sumatranus from Su- 

 matra or C. niger from Malacca, or whether it may be a 

 distinct species. Therefore I think it best, until we receive 

 skidls of the Tenasserim species, to give the Malaccan one a 

 distinct name and call it C. niyer (as the black colour at once 

 distinguishes it from the greyish Sumatran species), more es- 



