42 INDIAN TERTIARY AND POST-TERTIARY VERTEBRATA. 
difference from tlie type, I propose, as already said, that it should be known, at all 
events for the present, as 'Rhinoceros sivalensis y ar. gajensis. If the Gaj specimen 
were assigned to a distinct species, it would then he impossible to say whether the 
Manchhar upper molar should he referred to this new species with which it agrees 
in form, or to R. sivalensis with which it agrees in size. 
The dimensions of the Gaj specimen are compared below with those of the first 
upper true molar of R. javanicus, from which it will he seen that the two indicate 
an animal of the same size : — 
Var. gajensis. R. javanicns. 
Length of anterior surface 2 0 2'1 
„ of outer „ ...... 2 05 1*86 
„ of posterior „ 1’6 1*9 
„ of inner „ 1*15 1*3 
These measurements show that the same proportions pointed out above as dis- 
tinguishing the larger teeth of R. sivalensis from those of R. javanicus prevail in 
the smaller Gaj variety of the former. 
Distribution. — Remains of Rhinoceros sivalensis appear to have been obtained 
throughout the sub- Himalayan Siwaliks, from the Ganges to the Indus ; they have 
also been obtained from the lower Manchhar beds of Sind; while the variety, 
gajensis , occurs in the Gaj beds of the latter country. No remains of the species 
have hitherto been identified either from Burma or from Perim Island. 
Conclusion. — In conclusion, it may he predicated of R. sivalensis, if all the 
remains described above are correctly assigned to it, that it is an unicorn species, 
the form of whose cranium is intermediate between that of R. indicus and R. java- 
nicus ; and that its molar dentition and mandible are exceedingly like those of the 
latter, and very different from those of the former species. It is, however, dis- 
tinguished from the latter by the absence of median lower incisors. It was re- 
presented in the undoubted miocene by a smaller form presenting slight differences 
in the form of the molars from the typical pliocene form, and it is also possible there 
was a slight difference in the shape of the cranium of the earlier form, making an 
approach to the cranium of R. javanicus. The balance of evidence seems therefore 
to point to the intimate relationship existing between R. sivalensis and R. java- 
nicus, and to the probability of the one being the ancestor of the other. It is, however, 
as already said, somewhat difficult to understand the absence of median incisors in 
the adult fossil form ; and also in a lesser degree the greater apparent specialisa- 
tion in the form of the skull. 
Species 2. — Rhinoceros pal^eindicus, Ealconer and Cautley. 
Previous notices. — As far as can he discovered, no description or notice of this 
species was ever published by the authors of the “ Eauna Anti qua Sivalensis,” and 
the first appearance of the name seems to have been in that work, where several 
