PART 1.] 
Lydekker: Notices of Siwalik Mammals. 
93 
The jaw of Swatheriimi referred to is probably that of a male, other specimens 
being slightly smaller; the smaller or female specimens, however, have the same 
form and proportions as the larger. From the above measurements and com¬ 
parisons there can be no question as to the distinctness of the specimen from 
SivatJierinm. 
The teeth are readily distinguished from those of Bramatherium by their larger 
size and greater proportionate height; and from those of Vishmthermm by the 
absence of any cingulum or accessory tubercle, as well as by their much greater 
size. 
There now only remains the genus Hydasintliervmn of described genera to 
which the specimen can belong; and from the slight development of the costas | 
on the dorsa of the upper molars of that genus, and of the lower molars of the j 
present specimen, I think it probable that the latter should be referred to that j 
genus. I 
With regard to the question of species: the above-referred to cranium of i 
H. mecjacephalum is, from the fact of its bearing horns, no doubt that of a male j 
individual (the female of the allied genus Sivatherhmi being hornless) ; now, in ) 
that specimen the length of the last five teeth of the molar series is only 6T ? 
inches, while the length of the last five teeth in the present specimen is 9'2 \ 
inches; this clearly shews that the specimen could not have belonged to that i 
species. j 
Then with regard to S. grande : this, as wo have seen, is only known from upper j 
molar teeth, and there is therefore great difficulty in saying whether or no this i 
specimen belongs to that species ; another mandible, however, to be noticed imme¬ 
diately in the character of its lower molars, approaches nearer to the upper molars 
of S. grande, and I have accordingly provisionally referred the second specimen 
to that species. The present specimen must therefore belong to a third species, for 
which I jiropose the name of M. leptognatlius, with the proviso that subsequent { 
discoveries may render it necessary to change the generic prefix. | 
The present specimen indicates the existence of a slender-jawcd Sivatherioid, | 
which in the form of its jaw is a connecting link between the stout-jawed Siva- j! 
tlberium gigantewm and Camelopardalis sivalensis, in which the jaw is stoutei- I 
than in the living GlirafCe. The perpendicular inner border of the ascending | 
portion of the present jaw is quite peculiar, as far as is yet known. |i 
We have now to consider the poi-tion of a mandible which, I think, may very | 
probably belong to Hydaspitlierium grande; this specimen comprises a portion of j! 
the left ramus of the mandible containing the three true molars and the last | 
premolar; tlie jaw is broken off jjosteriorly immediately behind the last molar, ! 
and anteriorly some distance in front of the premolar; the teeth are only slightly | 
abraded by wear. 
This mandible differs from the last specimen by being much deeper, and by | 
being slightly concave instead of convex on the outer surface; in both of these 
respects it approaches to the jaw of Sivatlierium giganteum. The form of the I 
teeth, however’, at once distinguishes the specimen from the last-named genus, and % 
also from II. leptognatlius. The dorsa, or internal surfaces, of the teeth are placed | 
still more obliquely to the long axis of the jaw than in T[. leptognatlius ; and the fj 
f! 
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