B72. RHINOCEROS. 
both its shape, its partial bony septum, and the surfaces 
for the attachment of the horns; which surfaces are shown, 
by Dr. Kaup’s beautiful discovery, to be wanting in that 
accordingly hornless extinct Rhinoceros, which, by way 
of compensation, was provided with unusually large in- 
cisive tusks. (Kaup, loc. cit., p. 109, pl. x.) By the ab- 
sence of incisors, and by the form of the lower jaw, the 
Rh. leptorhinus resembled the incisorless Rhinoceros bi- 
cornis of the Cape; but, by the form and_ proportions 
of the cranium, it much more nearly resembled the two- 
horned Rhinoceros of Sumatra, and thus combined in its 
own organization characters now distinct, and shared be- 
tween two existing Rhinoceroses, the habitats of which, 
in the present geographical distribution of Mammalia, are 
divided by a thousand miles of ocean. 
Our chief information of the extent of the range of the 
extinct species of Rhinoceros is derived from the discoveries 
of their fossil teeth, which are the most common and the 
most recognizable remains of these great Pachyderms. 
Cuvier expresses his regret that he had had no oppor- 
tunity of examining the superior molar teeth of the Rhi- 
noceros leptorhinus, so that he knew not whether they 
presented characters analogous to those which distinguish 
the molars of the existing species. He appeals to the 
Italian naturalists to supply this hiatus; and to this de- 
sirable object the specimens which were obtained by Mr. 
Brown in the same deposits at Clacton, with the cranium 
and lower jaws of the leptorhine species, have greatly 
contributed. 
The upper molars from Clacton consist of the last and 
penultimate ones of the left side, and the ante-penultimate 
molar of the right side. If this tooth (fig. 141) be com- 
pared with the upper molar of the Rhinoceros tichorhinus 
