SIWALIK AND NARBADA PROBOSCIDIA. 
75—256 
Distribution. — Remains of M. sivalensis have been obtained throughout the 
sub-Himalayan Siwaliks, and not, as far as I am aware, elsewhere. 
General conclusions regarding Mastodon molars. 
The foregoing survey of such a large series of Mastodon molars has led to the con- 
clusion that the very regular ridge- formula given by Ralconer will not always hold 
good in regard to the true molars, though in the Indian species, at aU events, it 
appears to be always constant in the milk-molars. We have seen that there is a ten- 
dency in the true molars of some of the Trilophodons {M. falconeri) to develope the 
talon into a fourth ridge, and in the Tetralopliodons [M. latidens and M. sivalensis), 
a similar talon is developed into a fifth ridge, in the intermediate true molars. We 
thus see the passage from a Triloyhodm to a Tetralophodon, and from the latter to 
a Stegodon. 
We have no instance of a tooth with a certain number of ridges ever being suc- 
ceeded by a tooth with a smaller number : neither have we at present any instance of 
a trilophodont being mixed with a tetralophodont formula in the same species.^ 
Genus 2 : ELEPHAS, Linne. 
Elephants, whose intermediate molars always have more than five ridges, and 
in which cement is present in considerable quantity. 
Sub-Genus 1 : Stegodon, Ealconer. 
Elephants, whose intermediate molars do not generally have more than eight 
low ridges, and in which the cement does not form a continuous surface with the 
ridges in the germ molars. 
Species 1 : Stegodon CLiPTn, Ealconer and Cautley. Plate XL V, figs. 1 & 2. 
Synonyms : 8. sinensis, Owen. 
Mastodon elephantoides, Clift. 
History. — Remains of this species were first obtained by the late Mr. Crawfurd 
from strata near Ava, in 1826, and a specimen of the palate, and of the first upper 
true molar, were figured by the late Mr. Clift in the “Transactions of the Geologi- 
cal Society of London,”^ under the names of Mastodon latidens and Mastodon 
elephantoides. In the only part of the letter press of the “ Eauna Antiqua Siva- 
lensis,” which ever appeared, and which was published in 1846, the authors pointed 
* l am here referring only to Indian species, and do not therefore mention M. andium. 
* Second Ser., Vol. II, Pis. 36 and 39, fig. 6. 
