RHINOCEROS LEPTORHINUS. 



Fig. 138. 



convex transversely, concave longitudinally, with the free 

 lateral margins bent down. The 

 short septum is firmly anchy- 

 losed,* and gradually increases 

 in thickness to the anterior de- 

 flected extremities of the nasal 

 platform, where the appearance 

 of the fractured surface of the 

 confluent bones indicates that, 

 when entire, they had been united 

 by continuous ossification to the 

 intermaxillaries, as in the Rhino- 

 ceros tichorMnus.-f Very clear 

 evidence of the distinction of the 

 two species is obtained by com- 

 paring the upper surfaces of 

 . -i n j ,1 j Under surface of nasal bones of 



their skulls ; and the reader Rhinoceros kptorhinus. $ nat. 

 may pursue the same com- size ' Clacton - 



parison by means of the subjoined figure (139), and the 



* This fact shows that the limited extent of the bony septum in the present 

 cranium is not a consequence of immature age ; not only the size of the skull, 

 but the obliteration of the cranial sutures, proves it to have belonged at least to 

 a fully mature individual. In the tichorhine Rhinoceros the bony septum is 

 not anchylosed to the nasal platform until the animal has quite attained its 

 maturity. In the young but full-grown specimen discovered in the frozen sand 

 at Viloui, the bony septum was still free at its upper border. Pallas says, " Os 

 scutiforme, quod cornu nasalis firmamentum praestat cum subjecto fulcro osseo, 

 crassissimo vomeri comparando nondum evaluit ; sed harmonia tuberculosa totius 

 plani, ut epiphyses ossium juniorum solent, inarticulatur." Novi Comment. Pe- 

 tropol. xvii. (1773), p. 590. 



f When I first saw this specimen at Stanway during a tour of inspection of collec- 

 tions of British Fossils, preparatory to drawing up the Report on that subject for 

 the British Association, I was induced, from the prevalent belief in the osseous 

 septum anchylosed to the nasal bones as the peculiar characteristic of the Rhino- 

 ceros tichorhinus, to refer the Clacton cranium with those characters to that 

 species; this error in the 'Reports of the British Association,' 8vo., 1843, p. 

 222, I am now able to correct. 



