4 PACHYDERMATA. 



concur in restricting the narrow-toothed Mastodons of Europe to 

 a single species, the geographical range of which Cuvier extended 

 even to South America : while Croizet and Jobert, Kaup, Von 

 Meyer and others, divide them into two, M. longirostris, and M. 

 angustidens . No less than two genera, and at least ten nominal 

 species have been founded upon teeth which Owen, de Blainville, 

 and most other authorities, attribute merely to different ages and 

 sexes of a single species, the M. Ohioticus of North America. 

 In short, the ascertained fossil species, — exclusive of those of 

 India — according to some, are limited to one Elephant, and four 

 or five Mastodons ; while others would raise the number of the 

 former to ten, and of the latter to upwards of twenty. 



This great diversity of opinion, almost unequalled in regard to 

 any other section of mammalian palaeontology, has in a great 

 measure arisen from the isolated and often defective nature of the 

 materials relating to this tribe, as they ordinarily come before the 

 palaeontologist. From the peculiar mode of succession of the 

 molar teeth, which yield the principal distinctive characters in 

 Mastodon and Elephant, by repeated renewals from back to front, 

 at different stages of the animal's growth, as the worn and ex- 

 hausted grinders drop out, a limited number only of the whole 

 series can be met with in any one fossil specimen, even under the 

 most favourable conditions. It is this peculiarity which has so 

 long retarded the attainment of an accurate knowledge of the 

 dentition of the living species. The difficulty applies with double 

 weight to the fossil species, 1 for the teeth are rarely met with in 

 connexion with perfect crania and jaws : they most frequently 

 occur detached, or connected with mutilated fragments. It is only, 

 therefore, from the comparison of an extensive series of specimens, 



1 In illustration, it maybe mentioned, that Eichwald (Nova Act. Acad. Nat. Curios. 

 1834, vol. xvii. p. 735, tab. liii. fig. 2), in a memoir descriptive of fossil remains of 

 Elephas, Mastodon, and Dinotherium, &c, found in Poland, figures and describes what 

 appears to be a fragment of the symphysis of the lower jaw of Dinotherium giganteum, 

 as a portion of the upper jaw of a new species of Mastodon, which he names Mastodon 

 Podolieus. Other equally remarkable cases of the same kind might be adduced, so 

 unsafe is it to draw conclusions regarding the fossil Proboscidea from imperfect 

 materials. 



