301—124 INDIAN TERTIARY AND POST-TERTIARY VERTEBRATA. 
2 - 43 and D92 inches. The premaxillae, as in existing hyaenas, do not reach the 
frontals, but are separated by a space of \ inch. Apparently a similar condition 
prevails in lctitherium ,* Cynodictis , 1 2 and Canis. The proper occipital surface is 
essentially hyaenine. 
Mandible. — In figure 4 of plate XXXVIII., and in figure 6 of plate XXXIX., 
there are given two views of the anterior part of the left ramus of a mandible of a 
hyaenoid' animal, collected by Mr. Theobald in the Siwaliks of Jabi, which there is 
every reason to believe belongs to the same species as the skull described above. 
The specimen shows anteriorly the broken bases of two incisors (i) ; the bases of the 
canine (c), of pm. 1, and pmT2 ; the nearly complete pm. 3 and pmTi, and the alveoli 
of mTT ; behind which it is broken off. Part of the summit of pm. 4 has been carried 
away, but this and the preceding tooth are otherwise nearly perfect ; and being 
considerably worn indicate that the jaw belonged to a fully adult animal. The two 
remaining premolars are constructed on the type of those of Hycena ; but, as will be 
seen from the measurements given below, are considerably longer and narrower than 
those of any existing species of the genus. The first of these teeth (pm. 3) has a minute 
anterior, and a large posterior talon ; while in pmT4 both talons are large : and in the 
latter tooth there is a well-marked cingulum on the inner side of the hind talon, 
running forwards and inwards, as in II. striata. In addition to the elongated form of 
the two last premolars, the presence of pm. 1 and the long interval between the canine 
and pm. 2 distinguishes this specimen from the mandibles of both the preceding 
Siwalik species, and also from those of all the existing species. In the same 
characters the specimen agrees with the skull described above ; while in addition 
to this there is the circumstance, as will be seen from the measurements given 
below, that in the former the symphysis is unusually narrow (indicating a narrow 
palate), and the third incisor remarkably small. Since it will be shown below that 
this form of jaw is different from that of H. sivalensis, it may be taken as pretty 
certain that the present specimen belongs to the same species as the skull described 
above. 
The only non-Indian species of hyaena in which pm. 1 is normally present are 
II. eximia , II. brevirostris (?), H. grceca , and H. cliceretis. In the two former 3 the 
premolars are of the normal hyaenine type, and such appears also to have been the 
case with the third 4 ; in the fourth, 5 however, the premolars have very nearly the 
same proportions as those of the present specimen, as will be seen in the subjoined 
table of measurements, in which the dimensions of the latter are compared with 
those of II. cliceretis 6 and H. striata , 7 viz. : 
1 Gaudry, op. cit.. pi. VII., fig. 3. 3 Gaudry, op. cit., pi. XIII. 
2 Filhol, op. cit., fig. 58. 4 and 5 Ibid, pi. XV. 
6 These are mainly converted from the measurements given hy M. Gaudry, hut two are taken from his figure. 
7 These dimensions are means, and rather smaller than those of the skull given above. 
