6 
PAUNA OE THE INDIAN ELUVIATILE DEPOSITS. 
The mandible. 
The anterior or symphysial part of the mandible is prolonged beyond the 
premolars in a narrow beak-like projection unlike in 
form or proportion to any species hitherto described 
and figured. A correct idea of its form will be obtained by referring to figures 3 
and 4, Plate II. The peculiarity of this symphysial prolongation consists in its 
narrowness and in the sudden diminution in width in front of the permanent pre- 
molars. Bh. Etruscus, Ealconer, which of fossil species most resembles it, shows 
a less sudden constriction, if the term may be used, of the extension of the sym- 
physis in front of premolar 2, and the extension is moreover wider in proportion. In 
Bh. mger. Gray, the symphysis is narrow, but longer than in the Deccan species, 
and ends in a sharp toothless incisive border. Many species of Rhinoceros, both 
recent and fossil, ^show this extension of the symphysis, but instead of its being 
narrow throughout its length and constricted immediately in front of the premo- 
lars, it is wide at first, then narrows, and before reaching the incisive border spreads 
out again in a spatulate form. In many species large or moderate sized incisors 
project from the anterior border. In Bh. JDeccanensis the rather broken condition 
of the incisive border («. b. fig. 4, PI. II) renders it a 
The mclsois. little doubtful whether incisors had been developed there 
or not. If the small and irregular cavities observable in that situation were true 
alveoli, and probably they were so, the incisors must have been very small and 
rudimentary, as has already been mentioned above. There is no trace of them 
left, so they had probably been shed while the animal was alive. 
There are no indications of large mentary foramina Kke those so strongly 
developed in Bh. Etruscus. 
As already mentioned {ante, p. 6) the symphysis has been somewhat twisted 
by pressure, and the right ramus has been forced over considerably towards the 
left one, and the central part of the lower edge rather broken. The left ramus 
appears to be unaffected by the pressure, but has lost the coronoid process. The 
condyle is relatively small, the transverse length of the 
articular surface being only 3 inches, while the same part 
in an otherwise much smaller mandible of Bh. Sondaicus* measm’ed 3^ inches across. 
The curve of the ascending part of the ramus commences just below the median 
groove of premolar 3, The height of the ascending part of the ramus is 9T5 inches 
to the summit of the condyle, measured vertically from the smTace the mandible 
rested on, or 11’75 inches, measured with a tape along the posterior edge from the 
condyle to the angle. Erom the angle to the incisive border, measured along the 
under side of the ramus, is a distance of 19 inches. The left ramus only was 
measured, being much the more perfectly preserved. The posterior edge of the 
ascending ramus rises almost straight, and is not notched below the condyle as in 
Bh. Sondaicus and various other species. 
The ascending portion of the ramus. 
* In the collection of the Imperial Museum, Calcutta. 
