255—78 INDIAN TERTIARY AND POST-TERTIARY YERTEBRATA. 
That the fossil skull belonged to a fully adult individual is indicated by the fact 
that the true molars have been considerably worn down. Curiously enough the 
hinder cheek-teeth are slightly unequal in size on the two sides of the skull : in the 
following table, in which the dimensions of the specimen are compared with those 
of an adult skull of Canis bengalensis in the author’s collection, the teeth of the left 
side are measured. The respective dimensions of the two skulls are as follows, viz. : 
Length from hinder border of basisphenoid to hinder border of canine 
Width of palate at m. 1 . 
,, ,, „ ,, pm. 1 
Interval between carnassial and canine 
Zygomatic width at post-orbital process . . . . . 
Width across post-orbital processes 
„ of brain-case 
Length of pm. 2 
,, ,, 2 
C. cnrvipalatus. 0. bengalensis. 
3-44 .. 3-68 
1- 23 .. 1-3 
0-66 .. 0-6 
0- 7 .. 0-86 
2 - 121 .. 2-2 
1- i3 .. i-i 
1-67 .. 1-62 
0-22 .. 0-26 
0-24 .. 0-31 
0-35 .. 0-43 
0-36 .. 0-37 
0-27 .. 0-25 
On the right side the length of pm. 4 is 0-38 and that of raTT 0*33. 
It will be seen from these dimensions that the fossil differs from the recent skull 
in having the anterior part of the palate proportionately shorter and wider. In this 
respect it agrees more nearly with the Californian Canis littoralis ( of which the upper 
dentition is represented on the next page), and Otocyon ? In Canis bengalensis the 
proportionate length of pm. 4 to m. 1 is as 1 to 1T6 in the specimen of which the 
measurements are given here, and as 1 to 1T8 in the specimen measured by Prof. 
Huxley. In the fossil skull on the left side pm. 4 is shorter than m. 1 , and on the 
right side the proportion is 1 to 1 T 1 . This gives the remarkable fact that while on the 
right side the proportionate length of these teeth is very nearly the same in the two 
forms ; yet on the opposite side the proportion is about the same as in Otocyon , in which 
alone among all existing Canince pm. 4 is shorter than m. 1. The structure of the 
former tooth is, however, that of Canis ; although, as Mr. Bose mentions, the inner 
tubercle is relatively larger than in C. bengalensis ; a feature indicative of generalized 
affinities. There is no trace in the fossil of the minute anterior talon to the blade 
of pm. 4 existing in the living species. 
Coming to the true molars, it will be seen from the table of measurements that 
while m. 1 is slightly smaller in the fossil than in the recent form, m. 2 is considerably 
larger. From a comparison of the figures of the fossil and the upper dentition of 
C. littoralis in the woodcut on the next page (fig. 9), which is so close to that of 
C. bengalensis that it will answer the same purpose, 3 it will be noticed that while in 
the latter the lines forming the outer borders of the carnassial on the one hand, and 
1 Obtained by taking- twice the length of the left side. 
2 Huxley, op. at., fig. 11, p. 257. 
3 It should be remembered that the teeth of 0. littoralis are drawn £ larger than the natural size ; and that they are 
viewed from the opposite direction to that from which the other figures are taken. 
