SIWALIK AND NARBADA PROBOSCIDIA. 
107—288 
In the list of Prohoscidia given aliove, out of a total of thirty-eight species, 
no less than sixteen, or nearly one-half, belong to India, and fourteen of these to 
the Siwalik period. There is no better instance than the Prohoscidia of the enor- 
mous richness of the Siwalik fauna in large forms, and of their almost total 
extinction at the present day. The cause of this extinction has been attributed to 
the glacial period by Professor Huxley,^ who was followed by Mr. Wallace.^ 
In the table of ridge-formulge of the sub-genus Bueleplias given above, one 
very noticeable point presents itself, which I will shortly refer to. It will be ob- 
served that, with the remarkable exception of E. mnaidriensis, the arrangement of 
the species from their ridge-formulse, corresponds very closely with the order of 
their appearance in time, the two Pliocene species coming first, and then the 
Pleistocene and Recent species. Euelephas mnaidriensis occrn^s somewhat out of its 
position in time, in the ridge-arrangement : this, however, must probably be re- 
garded as a special instance of an earlier development of the higher type. 
Again, E. primigenius attained a higher development of its ridge-formula than 
its successor in time, the Indian elephant. 
With regard to the last-named species, it may be well to notice that Professor 
Boyd Dawkins® has recently expressed his opinion that E. primigenius is the parent 
of E. indicus, and that the latter is specifically identical with E. americanus {colum- 
hi) and E. armeniacus. I have not myself had an opportunity of examining a large 
series of the molars of these species, and the following remarks are, therefore, submit- 
ted with deference. In the first place, it seems to me somewhat improbable that the 
whole of the fossil Indian elephants were entirely swept away and replaced by a 
western form, which E. indicus must be according to Professor Dawkins, this replace- 
ment having probably taken place within the human period, as we have no evidence of 
the existence of the last-named species previous to that period in India. Purther, 
according to Dr. Palconer, the molars of E. primigenius are broader, and have thinner 
and more numerous plates than those of E. indicus, showing that the supposed descent 
would be retrogressive instead of progressive. Dr. Palconer ^ even goes so far as to 
place the two forms in distinct groups, E. primigenius belonging to his eurycoronine 
and E. indicus to his stenocoronine group. Again, the highly curved tusks of the 
mammoth are strangely unlike those of the Indian elephant.® I cannot at present 
indicate the line of descent of the latter species from any of the fossil Indian forms, 
but it may be observed that both the Narbada E. namadicus and the Siwalik 
(1879), the Siwaliks are generally classed as upper Miocene, and none of the mammals discovered since Falconer’s time 
are noticed. 
' Presidential Address to Geological Society of London, 1870, P. G. S. L., p. Ivii, 1870. 
^ “ Geographical Distribution of Animals,” Vol. I, p. 150. In the “ Manual of the Geology of India” (p. 587), 
Mr. W. T. Blanford attributes the origin of the theory of the extinction of the great mammals by the glacial period to 
Mr. Wallace, whereas it seems to have been first put forth by Professor Huxley in the passage quoted above. 
^ Quar. Jour. Geol. Soc., London, 1879. p. 145. 
Pal. Mem., Vol. II, p. 13. 
* I am informed by Mr. A. 0. Hume that a pair of tusks of the Indian elephant in the possession of one of the 
native princes are curved like those of the mammoth. 
