ELEPHANTIDJ3. 79 



There is no character by which the present genus can be distin- 

 guished from Mastodon; and the division can therefore only be 

 regarded as a matter of convenience. 



A. Stegodont Group. 

 The ridge-formula of* the cheek-teeth of the group embraces the 



fnllnwino- rar^P v\? —Mm 2 ' (4 " 5) • (5 " 7) M (6 " 8 ) • (6 " 8) • (7 ~ U) 



following range, viz. .—mm. 2 (4 _ g) (g _ 7) . m. (6? _ 7) . (6? _ 12) . (7 _ 13) . 



The ridges are comparatively low, broad, and tectiform, and the 

 valleys may be only partially filled with cement. The summits of 

 the unworn ridges are capped by numerous mammillae ; and the 

 crowns of the teeth may retain traces of the median longitudinal 

 cleft. The transition effected by E. clifti to Mastodon latidens is so 

 complete as to indicate that there is no real distinction between the 

 two genera \ In all those members of the group in which the 

 cranium is known, the vertex is relatively low, and the length from 

 the nasal aperture to the vertex is consequently comparatively 

 short, and the incisions of the temporal fossa on to the frontals are 

 comparatively small ; in both of which respects the group agrees 

 much more nearly with E. africanus than with E. indicus \ 



Elephas clifti, Falconer and Cautley 3 . 



Syn. Mastodon elephantoides, Clift 4 . ^j^y^^j^jy^^^c^Z, <-^«. 



Stegodon sinensis, Owen 5 . ™~* ' y > r ^*^/- y x \ \ V ". / ny . /, . / f < 



Stegodon clifti, Naumann t; . 



This species is still very imperfectly known; the ridge-formula 

 may be approximately given as Mm. Jf^f ; M. g^f'^Zgy The 

 ridges are low, and there is usually a more or less distinct trace of 

 the median longitudinal cleft on the crowns of the cheek-teeth, in 

 which the plane of wear is the same as in Mastodon. The valleys 

 of the teeth contain only a small quantity of cement, the enamel is 

 vertically grooved, and usually thinner than in Mastodon latidens, 

 while the number of cusps on the ridges is more numerous than in 

 that species. Premolars are present in one specimen provisionally 

 referred to this species ; and the mandibular symphysis was probably 



1 Pohlig ('Sitz. niederrhein. Q-es.' Feb. 4th, 1884) proposes to revert to 

 Cliffs view and class the Stegodont Elephants with Mastodon. 



2 Compare ' Fauna Antiqua Sivalensis,' pi. xlii. 



3 Fauna Antiqua Sivalensis, pt. 1, p. 47 (1846). 



4 Trans. Greol. Soc. ser. 2, vol. ii. pt. 3, p. 372 (1828). 



5 Quart. Journ. Geol. Soc. vol. xxvi. p. 417 (1870). 



6 Palaeontographica, vol. xxviii. art. 1, p. 9 (1881). 



