362 RHINOCEROS. 
Rh. leptorhinus. Rh, tichorhinus. 
In. Lin. In. Lin. 
Antero-posterior extent of last two molars : 4 3 33 CO) 
1D “A penultimate molar 4 0 1 9 
Transverse diameter of base of crown of penultimate Q 1 26 tee 
molar’ . - 
In the present specimen of the jaw of the leptorhine 
Rhinoceros (fig. 133), the worn state of the last two 
molars shows that it had belonged to an old individual : 
Fig. 134. but the difference of size is equally mani- 
fested by the specimen of a fragment of the 
left branch of the lower jaw of the Rhino- 
ceros leptorhinus (fig. 134), also obtained by 
Mr. Brown from the fresh-water deposits 
at Clacton, and containing the last three 
molars, in the same state of attrition as those 
in the Jaw of the Rhinoceros tichorhinus (fig. 
124). There is a difference also in the pro- 
portional size of the posterior lobe of the 
last molar tooth, which is greater in the 
Rh. leptorhinus. The lower terminations of 
the internal depressions of the molars are 
Rhinoceros lepto- 
rhinus. 4 nat. size. 
Walton. leptorhinus ; and the three inner columns or 
less angular and less narrow in the Lh. 
prominences of the molars are less flattened. 
The specimen of the fore part of the lower jaw of a 
somewhat younger leptorhine Rhinoceros, obtained by Mr. 
Brown from the fresh-water deposits at Clacton, Essex, 
and containing the second, third, and fourth premolars in 
situ (fig. 135), yields a specific character in the larger 
proportional size of the second premolar; which will be 
recognized by comparing the annexed figure with fig. 
128, and is demonstrated by the following admeasure- 
ments : 
