MASTODON ANGUSTIDENS. 273 



teeth of the typical species of Mastodon are compared with 

 those of the Elephants, in reference to their structure. 

 The dentine, or principal 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 Elephants. Such, at least, is the character of the 

 molar teeth of the first discovered species of Mastodon, 

 which Cuvier has termed Mastodon giganteus, and Mas- 

 todon angustidens. Fossil remains of proboscidians have 

 subsequently been discovered, principally in the tertiary 

 deposits of Asia, in which the number and depth of the 

 clefts of the crown of the molar teeth, and the thickness 

 of the intervening cement, are so much increased as to 

 establish transitional characters between the lamello-tuber- 

 culate teeth of Elephants, and the mammillated molars of 

 the typical Mastodons ;* showing that the characters de- 

 ducible from the molar teeth are rather the distinguishing 

 marks of species than of genera, in the gigantic probos- 

 cidian family of mammalian quadrupeds. 



* Mr. Clift had foreseen the possibility of the discovery of such a link, since 

 supplied by the praiseworthy exertions of Captain Cautley, and Dr. Fiilconer ; and 

 in his description of the Fossil Remains from Ava, in the Geological Transactions, 

 second series, vol. ii., he says, " It is not impossible that there may yet be 

 a link wanting, which might be supplied by an animal having a tooth composed 

 of a greater number of denticles, increasing in depth, and having the rudiments 

 of crusta pelrosa, that necessary ingredient in the tooth of the Elephant : the en- 

 tire absence of which distinguishes the tooth of the Mastodon.'''' Cuvier had pre- 

 viously enunciated the same supposed distinctive character between the struc- 

 ture of the teeth of the Elephant and Mastodon. " Dans l'616phant ces vallons 

 sont entierement combles par le cortical, tandis que dans le Mastodonte ils ne sont 

 remplis de rien." Ossemens Fossiles, torn. i. 4to, 1821, p. 225. Mr. S. Wood- 

 ward put forth a more remarkable, but not less erroneous opinion on this subject. 

 He says, " The distinctive characters of the grinders of the Elephant and Mas- 

 todon are so decided, that it is scarcely possible to mistake the one for the 

 other. The enamel of the former is disposed in pairs transversely, to the num- 



