260 P-ROCEEDINGS OF THE GEOLOGICAI, SOCIETY. 



agreement with the Mastodontoid rather than with the Elephantoid 

 type. Where nearly allied groups inosculate, the intermediate 

 forms commonly partake more or less of the character of both. But 

 the sum of the characters, and more especially the identical form of 

 the divisions of the crowns and the ridge-formula, connect this 

 species more with the other Stegodons than with any group of Mas- 

 todon. The next two species, namely, E. {Steg.) bomhifrons and E. 

 (Steg.) insignis, have from seven to eight, and occasionally even nine 

 ridges in their different intermediate molars ; and their teeth are ex- 

 ceedingly alike in character, although the species are distinguished 

 by an excessive amount of difference in the form of the cranium, 

 greater even than that between the African Elephant and the Mas- 

 todon of North America. Eegarding the specific distinctness of E. 

 (Steg.) Ganesa I am by no means so well assured ; this species 

 is chiefly founded on a huge cranium in the British Museum with 

 long tusks, presented by Colonel Baker. I have not been able to 

 reconcile the form of this cranium with either that of E. (Steg.) in- 

 signis or E. (>Steg.)bombifrons; but at the same time Imust confess that 

 I have failed in tracing its dentition satisfactorily as a distinct form 

 through different ages. Three species of this group appear to be 

 distinct beyond question ; and I cite them chiefly, on the present oc- 

 casion, in reference to determinations in the sequel, to show that 

 Elephantine forms may approach very closely in their dental cha- 

 racters, as occurs in other Mammalia, and still be distinct species. 



The Stegodons, so far as is at present known, are exclusively con- 

 fined to Tropical Asia. It is therefore unnecessary, on the present 

 occasion, to describe in detail the peculiarities of their dental cha- 

 racters ; and I shall confine myself to the leading points in their 

 "ridge-formula," that place them in connexion with the Mastodons 

 on the one hand, and with the Loxodons on the other. 



2. Elephas (Stegodon) Cliftii. — Of this species the youngest milk- 

 teeth are as yet iinknown. The third upper milk-molar, or first of the 

 intermediate molars, is seen in situin the specimen represented in the 

 ' Fauna Antiqua Sivalensis,' pi. 30. fig.l &, entire on one side, but worn 

 down to the common base of ivory, so that the divisions of the crown 

 have entirely disappeared, leaving no certain data for determining 

 the ridge-formula of this tooth. Behind it, in the same palate, 

 specimen from Ava (presented by Colonel Barnes to the British 

 Musemn) the three anterior ridges of the antepenultimate true molar 

 are seen in situ, the posterior half being broken off. But the de- 

 tached tooth on the upper jaw is seen entire, and beautifully pre- 

 served, in the specimen fig. 2 of the same plate, presenting six 

 ridges and a small hind talon. The same tooth is represented by 

 fig._ 6 of pi. 39 of Mr. Cliffs Memoir (Geol. Trans, vol. ii. 2nd 

 series). It is there described as an upper molar tooth of "Mastodon 

 elephantoides;' under which title Mr. Chft included specimens that 

 are referred in our arrangement to two distinct forms*. The Ele- 



* Mr. Clift, in liis excellent memoir, includes the Ava fossil Proboscideans 

 under two species, Mastodon latidens and Mastodon elephantoidcs. In the 

 ' Fauna Antiqua Sivalensis,' and in the synoptical table appended to the preced- 



