ELEPHANT AND MASTODON. 29 



certain species of Mastodon, the presence of which — first observed 

 bv Cuvier in M. angustidens — has been clearly established by 

 Kaup in the young of M. longirostris. The author of the ' Ost6o- 

 graphie' describes them as equally wanting in the Mastodons and 

 in the true Elephants. With respect to the species, while M. de 

 Blainville has judiciously rejected a great many of the nominal 

 forms which have been proposed on slender grounds, he appears 

 in other cases to have pushed this numerical reduction too far, and 

 to have mixed up under the same name species which are essen- 

 tiallv distinct. This remark applies especially to the Indian fossil 

 forms, three or four of which are combined under E. latidens ; and 

 to the European M. angustidens, which, as defined and illustrated 

 in the ' Osteographie,' includes two separate species. 



Professor Owen has been engaged upon the same subject, con- 

 temporaneously with M. de Blainville. In addition to the memoir 

 upon the North American Mastodon previously referred to, our emi- 

 nent countryman has discussed the systematic relations of Elephas 

 and Mastodon, in his ' British Fossil Mammalia,' and in his 

 very valuable work upon the teeth, lately published. On the latter 

 occasion, he showed, for the first time, that the molar teeth of the 

 Elephants and Mastodon, while they agree with each other, form 

 no exception from the normal division into sets, presented by the 

 ordinary Pachydermata (supra p. 11), and that the apparent 

 anomaly in the order of their succession, arises from the partial or 

 total suppression of the successional series of premolars. In the 

 former work, after describing the differences in the form of the 

 teeth of the two genera, he adds : — 



" A more important difference presents itself when the teeth of 

 the typical species of Mastodon are compared with those of the 

 Elephants, in reference to their structure. The dentine, or prin- 

 cipal substance of the crown of the tooth, is covered by a very 

 thick coat of dense and brittle enamel; a thin coat of cement is 

 continued from the fangs upon the crown of the tooth, but this 

 third substance does not fill up the interspaces of the divisions of 

 the crown, as in the Elephant. Such, at least, is the character of 

 the molar teeth of the first discovered species of Mastodon, which 



