SIWALIK AND NARBADA CARNIVORA. 
125—302 
Length of pm 1 
Width „ „ „ . . 
Length ,, „ 4 
Width „ „ „ .... 
Length ,, m. 1 
Depth ,, jaw at m. 1 
Greatest width of ramus at symphysis 
Interval between canine and pm. 2 
„ „ „ m. 1 
Antero -posterior diameter of canine 
,, ,, ,, ,, third incisor 
Transverse 
Specimen. H. chseretis. H. striata. 
. (?) 0-17 0-25 
(?) 0-56 0-64 0-52 
0-8 0-79 0-72 
0-43 0-5 
0-98 0-87 0-78 
0- 48 0-45 0-48 
(?) 0-9 0-94 0-81 
1- 6 1-44 1-39 
0-68 0-85 
0-68 0-51 0-45 
3-0 2-79 2-47 
0-65 0-64 0-68 
0-27 0-32 
0-17 0-22 
It will be seen from these dimensions that in the Siwalik jaw there is a greater 
difference in the respective lengths of pm. 3 and pm. 4 than in II. chceretis : the 
respective intervals between the canine and pm. 2, and m. 1, are moreover con- 
siderably smaller in the latter ; and it is not improbable that mTT was larger in the 
same. These differences are such as to render it improbable that the Siwalik jaw 
belongs to the European species ; although there can be no doubt that it belonged to 
a closely allied form. It is unknown whether m. 2 was present in either. The 
carnassial of the European form had a large talon and a distinct inner cusp to the 
blade ; whence it may be inferred that such appendages probably existed in the 
homologous tooth of its Siwalik ally. In the latter the middle incisor was thrust 
above the other two, as in existing species. The mandible bears two nervous 
foramina on the outer side ; whereas there is but one such foramen in II. chceretis. 
It may be remarked that in addition to the more slender form of the premolars, 
as compared with those of II. striata , the talons of pmT4 are considerably more 
developed than in that form. In the fossil pmT3 is narrower than pm. 4 ; the 
opposite condition prevailing in the recent species. 
Distinctness and affinities. — It now remains to consider the affinities of the species 
to which the above-described cranium and mandible belong. In the first place it 
will be apparent that the only described species with which they have any affinity is 
II. chceretis ; and since the mandible differs somewhat from that of the latter, it is 
probable that the Siwalik form should be referred to a distinct species, for which, 
from its most striking character, the specific name macrostoma is proposed. 
With regard to the generic title, Prof. Graudry in his description of II. chceretis 1 
remarks : “ La carnassiere inferieure de V Hyaena chaeretis est tres voisine de celte de Vhyene 
rayee et de V Hyaena arvernensis ; sa carnassiere superieure a aussi un aspect un peu hyenoide. 
C’ est pourquoi, en attendant qu' on ait trouve des pieces plus completes , nous laissons ce fossile 
aupres des hyenes. Nous voulons eviter de creer un nom de genre pour un animal 
imparfaitement connu ; mats ses premolaires si longues , etroites et ecartees , semblent annoncer 
quHl devra former un type nouveau. Nous ne savons point s’il avait une seule ou plusiers 
tuberculeuses ; les premolaires sont asses differentes de celles des hyenes pour faire supposer 
l Op. cit., vol. I., p. 94. 
