32 
MOLAR TEETH AND OTHER REMAINS OF MAMMALIA. 
from tertiary beds at Kusbalgliar, near Attock, the precise age of which has not yet 
been determined. A portion of the posterior collis was broken, which has been 
restored in the figure. 
The crown is very unsymmetrically shaped, the posterior valley {right of 
figure) being greatly larger than the anterior valley {left of figure) ; the posterior 
half of the tooth is worn down a quarter of an inch below the anterior half. The 
dentine surface joining the posterior collis with the outer wall of the tooth is 
situated obliquely to the long axis of the crown : the median collis exposes the 
largest dentine surface ; its postero-internal angle is acute ; the posterior collis 
{extreme left of figure) is smaller than either of the others, its innermost border 
not extending so far inwards as those of the other two colles. 
The inner border of the tooth presents a nearly continuous wall for some 
distance up on the crown, which takes away from the prominences of the colies, 
usually so conspicuous in the lower molars of other species of Rhinoceros. The 
anterior valley is entered by a small and narrow pass through this innermost wall. 
The entrance to the posterior collis is blocked for half its length by the inner crown- 
wall. Behind this there is an open space of rather more than a quarter of an inch 
in width leading directly into the valley ; the inner wall is again continued on the 
anterior aspect of the posterior collis. The narrow channel leading into the posterior 
valley is slightly higher than the bottom of the outer extremity of the valley. 
When the crown becomes worn down, the outer extremity of the posterior valley 
would be left as an isolated fossette upon the crown surface, the outer extremity of 
the valley disappearing last ; in the lower molars of all other species of Rhinoceros 
which I have seen described, except those of Rhinoceros simus of Africa, which 
have the same peculiarity as this specimen, the posterior valley is shallower on the 
external than on the internal side, and consequently never forms an isolated 
fossette on the crown, but merely forms a shelving notch on the inner border. 
The whole of the anterior valley on this specimen would disappear at an early 
stage of wear. There is no cingulum on any part of the crown. The enamel is 
thinner on the inner than on the outer side of the tooth. 
The flatness of the inner wall of the tooth, together with the peculiar shape of 
the posterior valley, sufiiciently distinguish the specimen from the lower molars of 
any of Falconer’s species of Siwalik Rhinoceros ; the dimensions are — 
In- 
Extreme length ... ... ... ... 
Breadth at centre ... ... ... 1-2 
A single lower premolar of Rhinoceros merhkii figured in Gervais’ “Faldon- 
tologie et Zoologie ” ( Rlate XIV, Fig. 3 ) shows a fossette on the worn crown, 
representing the posterior valley ; but there is none on the molars of the same 
specimen. 
I have but little doubt that this tooth belonged to another distinct species of 
Rhinoceros, which must have had affinities with the African R. simus, 
( 50 ) 
