SIWALIK AND NARBADA CARNIVORA. 
161—338 
pm. 4 
Fig. 19. Machcerodus 
sivalensis (Falc. and 
Caut . ) . Hinder cheek - 
teeth : from the Siwaliks. 
British Museum (No. 
39,730). i. 
Maxilla . — In plate XLIV., fig. 2, there is represented from the external aspect 
the left maxilla of a machserodont in the Siwalik collection of the 
British Museum, apparently belonging to the present species. 1 
The accompanying woodcut (fig. 19) represents the palatal aspect 
of the two hinder cheek-teeth of the same specimen. In this 
maxilla three cheek-teeth are present; viz ., pm. 3 , pm. 4 , and m. 1 . 
The first of these is not fully protruded (indicating the sub-adult 
age of the animal) ; and is remarkable for its unusually small 
size (showing that the specimen cannot belong to a Felis) ; it is 
inserted by two fangs, and has no distinct talons. The carnassial 
has a small talon in advance of the first lobe (the summit of which 
is broken) : the three lobes have much the same proportions as in 
Felis ; but the whole crown is relatively narrower, and the inner 
tubercle' reduced in size, and not extending so far forward as in that genus. 2 The 
form of this tooth indicates that the specimen should be referred to Machcerodus. 
The true molar is a very small tooth with an oval crown. The dimensions of this 
specimen are as follows, viz . : — 
Length of pm. 3 .... 0-45 Antero -posterior diameter of m. 1 . 0 ■ 1 5 
,, ,', ,, 4 . . . l - 3 Transverse ,, ,, ,, ,, . 0'27 
Since the length of pm. 4 is equal to that of the corresponding tooth of the 
small tiger’s skull referred to above ; and since the length of the two first cheek- 
teeth bears the same proportion to the length of the lower cheek-teeth of M. 
sivalensis as obtains in the corresponding parts of M. meg anther eon, the present 
specimen may be pretty certainly referred to a small individual of the former species. 
That species is, therefore, distinguished from all the other forms of which the skull 
is known, with the exception of M. meg anther eon, by the small size of, and absence 
of talons to, pm. 3 . This is very noteworthy, since in both M. neogceus and M. necator 
the same tooth has distinct fore-and-aft talons. The upper carnassial of the former 
is distinguished from the Siwalik tooth by the reduplication of its anterior lobe ; a 
similar character also prevailing in M. fatalis ; but in M. necator this tooth has the 
same structure as in the Siwalik species. The carnassial of M. megantliereon is also 
very similar to that of the Siwalik species ; its inner tubercle being very small. 
The minute size of m. 1 in M. sivalensis distinguishes it from M. neogceus : in M. 
necator , according to Prof. Cope’s figure, this tooth is absent. 
Maxilla of a cub . — In figures 1, la of plate XLIV. there is represented the right 
maxilla of a Siwalik Machcerodus cub, in the British Museum, showing the milk 
dentition. 3 The teeth present are the broken canine, and the carnassial (mm. 3) • 
1 This specimen is also represented in the “ F.A.S.,” pi. N., figs. 5, 5a ; and is described in Mr. Bose’s memoir (op. at., 
p. 124). 
2 Mr. Bose states that this tubercle is absent. 
3 This specimen is also figured in the “ F A.S.,” pi. N., figs. 3, 3a ; and, from the palatal aspect, in fig. 5 of the plate 
accompanying Mr. Bose’s memoir. 
N 2 
