291—114 INDIAN TERTIARY AND POST-TERTIARY VERTEBRATA. 
These dimensions show that while the length of the palate of the specimen 
under consideration is nearly the same as in II. felina, its width is considerably less ; 
as is well shown by the interval between the canines and the space occupied by the 
incisors. In the following table the dimensions of pm. 4 are compared with those of 
the maxilla (a) and the Dublin (b) skull of II. felina , and also with the above-mentioned 
tooth of II. crocuta from the F orest-bed : — 
H. felina. Specimen. H. crocuta. 
Total length . 
Width across tubercle 
Length of first lobe 
,, ,, second lobe 
,, ,, third lobe 
1-55 
0-86 
0-38 
0-45 
0-38 
0-58 
It is thus shown that this tooth is relatively larger than in II. felina , and has its middle 
lobe more developed; although considerably narrower across the tubercle. In respect 
of its larger middle lobe it is more like pm. 4 of II. crocuta , but is still distinguished 
by its smaller third lobe : its tubercle is considerably smaller than in that species. 
As in both II. felina and II. crocuta , the tubercle extends as far forwards as the blade. 
The length of this tooth exceeds the united length of the two preceding teeth ; the 
reverse condition prevailing in II. felina. The true molar ( m, 1 ) is of the elongated 
striatine type, and thereby differs markedly from the corresponding tooth of II. 
felina. Pm. 3 is a characteristic tooth, perfectly distinct from the corresponding tooth 
of the latter : it is set very obliquely to the line of the molar alveoli, and has only a 
minute hind talon, continued to the summit of the crown as a sharp ridge ; while a 
similar ridge occupies the antero-internal side of the crown, the base of which 
probably represents an anterior talon, placed internally, instead of at the anterior 
border. Between these two ridges there was originally a distinct cingulum on the 
inner side, which unfortunately broke away before the specimen was figured. The 
vertical ridges and the cingulum enclose a flattish triangular space on the inner side, 
which may conveniently be termed the ( triangle.’ This tooth is relatively shorter 
antero-posteriorly, and taller vertically than in II. felina and II. sinensis ; while its 
hind talon is smaller, and its ‘ triangle ’ totally wanting in the other forms, which 
also lack the large inner cingulum. The external convexity is as well-marked in all. 
It is also smaller in proportion to pm. 4 than in II. felina , as may be seen by a 
comparison of the measurements ; and is totally different from the corresponding 
tooth of II. striata ; though somewhat more like that of II. brunnea, which, however, 
has larger talons, and a less distinct 1 triangle,’ with a more convex inner surface, 
and a lower crown. The corresponding tooth of It. crocuta has a similar tall crown, 
and a more or less distinct ‘ triangle,’ though the distinctness of this varies 
considerably in different individuals, 1 and is never quite so well-marked as in the 
Siwalik fossil. The hind talon of pm. 3 is moreover considerably smaller in the fossil 
than in II. crocuta ; but in general contour the teeth of the two forms have a very 
1 In two fine recent skulls in the Royal College of Surgeons (Nos. 523, 524) the ‘ triangle ’ is much more distinctly 
marked in the former (a specimen collected by Gordon Gumming) than in the lattei . 
