28 PACHYDERMATA. 



that the characters presented by the number as well as by the form 

 of all the parts of the skeleton are alike in both ; that the separate 

 bones are so precisely similar that, when met with detached, it is 

 exceedingly difficult to decide whether they belong to Mastodon 

 or to Elephant ; that, as regards the structure of the teeth, there is 

 a series of intermediate gradations forming a passage from the one 

 genus into the other ; and that the observed differences in these 

 organs are systematically of no greater signification than as indica- 

 tive of the kind of vegetable food upon which the several species 

 subsisted. 1 Guided by these views, M. de Blainville has abandoned 

 Cuvier's genus of Mastodon, and, like the earlier observers, he 

 has united it with the Elephant, under the common generic name 

 of Elephas, of which he forms two sections, Lamellidontes and 

 Mastodontes. The former includes the Elephants proper, viz., 

 the two existing species, with E. primigenius doubtfully admitted 

 as a distinct form, and E. latidens, under which name he unites 

 the two species M. Elephantoides and M. latidens, described 

 by Clift. Of the second section, comprising the typical Mas- 

 todons, M. de Blainville admits only four species, viz., E. 

 (M.) Ohioticus, E. angustidens, E. Andium, and E. Tapi- 

 roides, together with M. Sivalensis as a doubtfully established 

 species. M. de Blainville's work is illustrated with an admirable 

 series of representations of the osteology and dentition of the 

 different species, and he has made a valuable contribution to the 

 palaeontology of the Proboscidea, by defining the character of 

 M. Andium, which was distributed among several nominal species 

 by Cuvier. He has also thrown considerable light on M. Tapi- 

 roides, by means of the materials collected by M. Lartet, in the 

 south of France, which he has combined under this specific name, 

 with remains derived from different parts of Europe. But there 

 are weighty objections to the rest of the details of this portion of 

 the * Osteographie.' Although the consideration of the teeth is 

 of paramount importance in every question connected with zoolo- 

 gical arrangement, it is to be remarked, that M. de Blainville has 

 nowhere adverted to the occurrence of premolars in the upper jaw of 



1 Loc. cit. p. 2. 



