RHINOCEROS LEPTORHINUS. 357 



Cuvier to the species in question, were suggested by the 

 characters of the fossil skull of a Rhinoceros discovered by 

 M. Cortesi in a fresh-water upper tertiary deposit at Plai- 

 sance, as they appeared in a drawing transmitted to Cuvier, 

 who had not had an opportunity of studying the original, 

 which is preserved in the ' Musee des Mines 1 at Milan. 

 Confiding in the drawing, which is engraved in the ' Osse- 

 mens Fossiles,' 4to., 1822, torn, ii., pt. i., Rhinoceros, pi. 

 ix., fig. 7, Cuvier was led to conclude that the Rhino- 

 ceros of Plaisance differed from that of Siberia and north- 

 ern Europe in having " the cerebral part of the skull less 

 prolonged and less inclined backwards ; in the position 

 of the orbit above the fifth molar tooth ; in the anterior 

 termination of the nasal bones by a free point, and in 

 the absence of any attachment of them to the intermaxil- 

 laries by a vertical osseous septum ; in the minor degree 

 of prolongation of the intermaxillary bones, which were 

 of a totally different form, presenting, in short, as 

 little as the nasal partition, any of those characters for 

 which the skull of the Rhinoceros tichorhinus was so re- 

 markable." (Tom. cit. p. 71.) From these apparently 

 broad distinctions, Cuvier did not hesitate to admit the 

 specific difference of M. Cortesi's Rhinoceros ; and he even 

 ventured to state that it incontestably approached nearer 

 to the Rhinoceros bicornis of the Cape than to any other 

 known species. (Tom. cit. p. 71.) 



This summary of the cranial characters of the Rhinoceros 

 leptorhinus is repeated without modification in the post- 

 humous 8vo. edition of the ' Ossemens Fossiles,' 1834, 

 torn, iii., p. 136. 



In the following year, however, M. de Christol commu- 

 nicated to the ' Annales des Sciences, 1 2 de s6rie, torn, iv., p. 

 44, a more accurate figure (pi. ii, fig. 4) of the cranium 



