307—130 INDIAN TERTIARY AND POST-TERTIARY YERTEBRATA. 
teeth being consequently the same as in living hyaenas. In the other specimen 
(plate XXXIX., fig. 5), however, there is behind mTI the circular alveolus of a small 
in. 2, which is normally wanting in most other forms. In this specimen, m. 1 has a 
large talon (the summit broken), and a relatively small blade, on the inner side of 
the hinder lobe of which there is a small cusp. The form of this tooth shows that 
the mandibles under consideration 1 belong to a species of II/jcena, having carnassial 
teeth of the type of those of II. striata ; and presenting, therefore, no sort of affinity 
with II. felina and II. colvini. Before proceeding with the description of the 
specimens their dimensions may be given, and compared with those of II. striatal and 
H. macrostoma : — 
Length of pm. 2 
Width „ „ „ 
Length ,, ,, 3 
Width „ „ ,,- 
Length ,, ,, 4 
Width „ „ ,, 
Length ,, m. 1 
Width „ „ ,, 
Depth of jaw at m. 1 
,, ,, ,, ,, pm. 2 
Greatest width of ramus at symphysis 
Interval between canine and pm. 2 
Space occupied by 4 cheek-teeth 
Antero -posterior diameter of canine 
,, ,, ,, ,, third incisor 
Transverse „ ,, ,, ,, 
H. striata. 
0-52 
0-32 
0-72 
0-5 
0-78 
0-48 
0-81 
0- 4 
1- 39 
1- 36 
0-85 
0-45 
2- 47 
2-68 
0-68' 
0-32 
0-22 
Specimens. 
B. M. I. M. 
0-53 
0-31 
0-74 
0-41 
0-8 0-83 
0-42 0-44 
0-89 0-88 
0- 44 0-44 
1- 4 1-36 
1- 3 
0-7 
0-44 
2- 43 
2-88 
0-56 
0-26 
0-2 
H. macrostoma. 
0-56 (?) 
0-8 
0-43 
0-98 
0-48 
0- 9 (?) 
1- 6 
1-29 
0-68 
0-68 
30 
0 65 
0-27 
017 
It will be seen from this table that the specimens under consideration are 
distinguished from the mandible of II. macrostoma by the much smaller interval 
between the canine and pm. 2, and by the premolars being absolutely smaller and 
relatively shorter and wider ; being in fact about intermediate between the teeth of 
that species and II. striata. These differences, coupled with the absence of pm. i in 
the specimens under consideration, leave no doubt that they are specifically distinct 
from H. macrostoma. The only species of Siwalik hyaena to which they can, there- 
fore, belong is II. sivatensis ; and as they agree with the skull of that species in 
having carnassials of the striatine type, in their premolars being relatively somewhat 
narrower than those of II. striata , and in the shortness of the diastema, while the 
British Museum mandible corresponds precisely in size to the type skull of IT. 
sivatensis, it is practically certain that the mandibles under consideration belong to 
that species. 
Resuming the description of the lower teeth, the inner cusp of m. 1 of II. 
sivatensis is rather smaller, and placed slightly farther back than in II striata ; 
1 The British Museum specimen of this tooth is too worn to show its characteristic points. 
2 The dimensions of this species are means, and rather smaller than those of the skull of that species given in the 
preceding table. 
