ELEPHANT AND MASTODON. 19 



other species of his new genus, viz., M. angustidens, in which he 

 included all the narrow Mastodon molars found in Europe, 

 together with some from America ; two species from South 

 America, M. Andium and M. Humboldtii; and a small European 

 species which he named M. minutus. To these were subse- 

 quently added, in the ' Ossemens Fossiles,' a sixth species, under 

 the name of M. Tapiroides. 



In regard to the number and succession of the teeth, while he 

 admitted eight molars on each side of both jaws to the Elephant, 

 this great Anatomist, not hazarding a conjecture beyond the 

 materials which had come under his eye, was not aware of more 

 than four on each side in the Mastodon, or sixteen in all. He 

 was also without the knowledge of the occasional presence of 

 tusks in the lower jaw ; but he first made the important obser- 

 vation, that in the Mastodon angastidens a part of the anterior 

 series of molars in the upper jaw is replaced by a vertical succes- 

 sional tooth, or true premolar, thus bringing them under the normal 

 law of the order of Pachydermata, by showing a division into a 

 milk and permanent set. The Dax specimen, figured in the 

 1 Ossemens Fossiles ' (Divers Mast. PI. 3. Fig. 2), clearly 

 establishes this point ; and the signification of the structure is 

 distinctly, although guardedly, explained by Cuvier in the descrip- 

 tive part of the work (torn. i. p. 256). But he was less happy in 

 the definition of his species. Under the name of Mastodon 

 angustidens, he has included two very distinct forms, characterized 

 by a different numerical formula in the crown ridges, viz. M. 

 angustidens and M. longirostris ; and the South American 

 teeth which he distributed among three nominal species, M. 

 angustidens, M. Andium, and M. Humboldtii, appear to be all 

 referable to a single form, M. Andium of M. de Blainville. 

 We agree also with the latter authority, in considering the tooth 

 upon which M. minutus is founded to be nothing more than an 

 anterior molar of a young M. angustidens. 



Cuvier's opinion was first called in question by Tilesius, in 1815, 

 in his memoir upon the skeleton of the frozen Mammoth, disco- 



c 2 



