SIWALIK AND NARBADA CARNIVORA. 
163—340 
similar production of the zygomatic .process of the squamosal, 1 which is but partly 
preserved. The posterior border of the former 
process inclines forwards at a ,large angle with 
the long axis of the skull. The downward 
production of the mastoid and zygomatic 
processes indicates affinity with M. neogceus, M. 
necator, and M. fatalis , in which the glenoid 
m fossa is situated in the plane of the dental 
alveoli, instead of far above it as in Felis, M. 
meg anther. eon, and (?) M , cultridens. As this 
arrangement is necessarily correlated with a 
Fie. 20 . teV and * ma11 coronoid process to the mandible, its 
Caut.). Hinder part of cranium, from the existence in the present skull serves to confirm 
Siwaliks : Indian Museum (No. D. 63): con, . ,. . , . „ . „ . 
condyle ; p, paroccipital process; m, mastoid the Conclusion as to the Specific Ulllty of the 
process of periotic: zy, zygomatic process of latter with the mandibles described above, 
squamosal, • broken inferiorly : m a, auditory . 
meatus. It may be observed that the production of 
the zygomatic process permits a much wider opening of the mouth, and is, therefore, 
associated with the largest development of the canines. The presence of this 
feature in M. sivalensis accordingly confirms the inference as to the large size of 
those teeth in that species. 
The posterior border of the mastoid process in the skull under consideration is 
more nearly vertical than in M. neogceus or M. necator. In the backward extension of 
the occiput over the condyles the Siwalik skull agrees with the latter, and differs 
from the former species (woodcut fig. 17).’ The upper part of the occipital surface 
is not unlike that of the tiger, but has rather more lateral expansion superiorly. The 
width across the condyles is two inches, or nearly the same as in a small tiger’s 
skull ; the other parts of the fossil skull being relatively smaller. 
Affinities . — Summing up the results of the foregoing comparisons, it appears that 
Machcerodus sivalensis is a species coming nearer in its main cranial characters to the 
American M. neogceus , and M. necator , than to the European M. meg anther eon, and 
(probably) M. cultridens. It apparently agrees with the two former in its relatively 
large canines ; while in dental characters it presents a strong general resemblance to 
M. necator , although lacking the suppression of pm. 3 ; and in the structure of pm. 3 
agreeing with M. meganthereon. .In the small size of m. 1 the Siwalik species again 
comes nearest to M. necator. In the variation in size of pm73, and in the tendency 
to the disappearance of the second fang of this tooth, the species is evidently 
intermediate between the European and the American forms. 
On the whole, M. sivalensis must be regarded as decidedly nearest to the 
American species forming the so-called genus Smiloclon , but presenting such inter- 
1 Since in some machserodonts the whole glenoidal region of the squamosal is much produced, it will be more convenient 
to apply to this part the term £ zygomatic ’ rather than ‘ post-glenoid ’ process ; which should he strictly confined to the 
prominence below and behind the glenoid fossa. 
