70 
Records of the Geological Survey of India. [vol. xr. 
Next, with regard to the question of species : the teeth are smaller than those 
of M. silenus, If. rhesus, and If. radiatus, and judging from the relative size of 
31. radiatus and 31. 'pelops, the teeth of the latter would also he larger than those 
of the present specimens; again, in 31. rhesus and in all other living sjjecies of the 
genus which I have seen, the anterior root of the zygoma is placed always behind 
the interval between the first and second molars, whereas in the fossil specimens, 
this root s exactly over this interval. 
I have not oeen able to compare the fossil specimens with the teeth of other 
living species of 3Iaeaeus; but as the former differ from the Indian species of 
the genus, and as all known Siwalik species of Mammals are extinct, the presump¬ 
tion is that the present specimens also belong to an extinct specie.s. 
Turning now to the fossil species of 31amcus, we find that the following have 
been described; the small lower jaws described by Falconer from the Siwaliks 
and referred to above; a lower jaw from the London clay described by Professor 
Owen under the name of 3Iaoaous eocenus; ^ a portion of an upper jaw from 
the newer pliocene of Grays described by Professor Owen as 31. pliocenus ; ^ 
and a lower jaw from the pliocene of Montpellier desci'ibed by Professor Gervais 
under the name of 31. prisms.^ 
The small lower jaws from the Siwaliks described by Falconer belonged to an 
animal larger than 31. rhesus, while Mr. Theobald’s specimens belonged to an 
animal smaller than 31. rhesus; now, since Falconer obtained two specimens of 
the lower jaw which agreed exactly in size, and since Mr. Theobald has also 
obtained two specimens of the smaller upper jaw, which also agree exactly in size, 
it seems to be probable that the latter belong to a different species from the for¬ 
mer. The jaw on which 3Iacacus eocenus of Owen was founded has been sub¬ 
sequently refci*red to Hyracothermm.* 
Both 31. plioeenus and 31. priscus are too large to have belonged to so small an 
animal as that to which Mr. Theobald’s specimens belonged. 
It is therefore clear that the latter teeth do not belong to any named fossil 
species, and there is every probability that they do not belong to any living 
species : this being so, I shall propose to call the species If. sivalensis. 
PROBOSCIBIA. 
Genus: Mastodon. 
I have already said in the Introduction that an adolescent cranium of the new 
Siwalik Trilophodont 3£astodon ^ has been found in the Potwar; this cranium 
contains the two last upper milk-molars and the first true molar; a detached second 
upper true molar of the same species has also been obtained from the Siwaliks ■ 
and several detached teeth from Sind. These specimens appear to prove the 
specific distinctness of 3Iastodon falconeri. 
’ Brit. Foss. Mara, and Birds, p. 1. ® Zoologie et Baleontologie Frangaises, p. 11. 
^ Sup. cit. Int., p. xlvi. ’ Nicholson’s Palseontologj, p. 466. 
^ Eec. Geol. Suit. India, Vol. X, p. 83. 
