ELEPHANT AND MASTODON, 



63 



nation of Missourium.^ Professor Owen, on this occasion, 

 reviewed the whole of the evidence respecting Tetraccmlodon, 

 and, in a masterly communication to the Geological Society, 

 extended the objections urged by the American naturalists, by 

 numerous and forcible analogies drawn from the dentition of 

 the Dugong and ISTarwahl, besides some of the ordinary 

 Pachydermata.^ He arrived at the conclusion that the 

 Mastodontoid animals of North America are aU strictly refer- 

 able to a single species, which ' has two lower tusks origi- 

 nally in both sexes, and retains the right lower tusk only in 

 the adult male.' Dr. Grant entered upon an elaborate in- 

 vestigation of the same subject soon afterwards, and was led 

 to very different results.^ He divides the proboscidean 

 pachydermata into four genera, Elephas, Mastodon, Tetracau- 

 lodon, and Dinotherium, to each of which he attributes a 

 different dental formula. He admits thirteen species of 

 Mastodon, and discriminates six species of Tetracaulodon 

 among the mastodontoid animals of North America. Mr. A. 

 Nasmyth adopted similar views, from a minute microscopical 

 examination of the structure of the tusks in these extinct 

 animals ;^ but the importance of the differential marks indi- 

 cated by Dr. Grant and Mr. Nasmyth has not been admitted 

 by subsequent observers, as characterizing more than indi- 

 vidual and sexual varieties in different animals of the same 

 species. The generally received opinion at present is that 

 M. Ohioticus is the only mastodontoid form hitherto met with 

 in North America. 



In the additions to the last edition of the 'Ossemens Possiles,' 

 Cuvier has recorded the discovery of fossil grinders of 

 mastodon, in the Lignite beds of Koepfnach and Ellg in 

 Switzerland, which he has referred to his ' Mastodonte a 

 dents etroites.'^ Some of these remains have been described 

 by Schinz as indicating a distinct species for which he has 

 proposed the name of M. Turicensis.^ M. de BlainviUe refers 

 them to M. Tapiro'ides, as defined in the ' Osteographie.' 



' Koch has lately published a sepa- 

 rate memoir, in which the Missourium 

 is figured and perpetuated with all its 

 original exaggeration. He has given it 

 the appropriate specific name of M. the- 

 ristocaulodon the tusks being invested 

 with the functions of a sort of scythe. — 

 A. C. Koch, ' Die Eiesenthiere der Ur- 

 welt oder das neu entdeckte Missourium 

 theristocaulodon und die Mastodonten 

 im Allgemeinen und Besondern.' Berlin, 

 1845. 



^ Owen, ' Proceedings of the Geol. 

 Soc' Feb. 1842; vol. iii. p. 669 ; ' Eeport 

 on the Missourium. 



' Grant, loc. cit. June 1842, p. 770, 



' On the Structure and History of the 

 Mastodontoid Animals of North Ame- 

 rica.' 



* Nasmyth, loc. cit. June 1842, p. 775, 

 ' On the Minute Structure of the Tusks 

 of Extinct Mastodontoid Animals.' 



5 Oss. Poss. 8vo. edit. 1834, tom. ii. 

 p. 366. 



^ Schinz, quoted in von Meyer's ' Pa- 

 Iseologica,' 1832, p. 72, and in Bronn's 

 ' Jahrlsuch ' of 1839, p. 2 ; mentioned in 

 Jameson's Edin. New Phil. Jour. vol. v. 

 1828, p. 273, as a communication to the 

 Helvetic Soc. of Nat. Hist, in August, 

 1837. 



