58 



FAUNA ANTIQUA SIVALENSIS. 



Pacliydermata, by showing a division into a milk and perma- 

 nent set. The Dax specimen, figured in the ' Ossemens 

 Fossiles,' ^ clearly establishes this point ; and the significa- 

 tion of the structure is distinctly, although guardedly, ex- 

 plained by Cuvier in the descriptive part of the work.^ But 

 he vpas less happy in the definition of his species. Under the 

 name of Mastodon angwstidens he has included two very dis- 

 tinct 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 mam- 

 moth, discovered by Mr. Adams in Siberia.^ He repudiates 

 the vaHdity of the grounds for separating mastodon from 

 elephas, in terms of such strong dissent as to have excited 

 the indignation of the French philosopher : ^ ' Cuvierus in 

 tractatu suo de hac specie (M. giganteus) quam injuste ab 

 elephantorum genere separavit quamquam non solum dentes 

 molares, in quibus male genericam diversitam^ queesivit 

 lamellosse sunt structurse, ut omnes reliqui elephantorum 

 molares sunt, sed etiam totum animal characteribus genericis 

 elejDhantorum respondeat ejusdem opinionis est.' Cuvier's 

 division, however, has been adopted by every siibsequent 

 writer except M. de BlainviUe, who coincides with the view 

 taken by Tilesius. 



A still more important oversight was made by the founder 

 of the genus, in regard to the statement which he advanced 

 of the entire absence of ' crusta petrosa,' or ' cortical ' from 

 the molars of mastodon. It is true that this substance is 

 not present in an appreciable quantity in M. Ohiotieus, and 

 that it is also but very sparingly developed in M. angustidens 

 and M, longirostris ; but, in M. Andium, a typical form of the 

 genus, this substance exists in a layer of considerable thick- 

 ness, which we have observed in almost all the teeth of the 

 species, contained in the museum of the Jardin des Plantes, 

 including the specimens brought by Dombey, Humboldt, and 

 Gay, from Chili and Peru, and also in the rich series of 



' Divers Mast. pi. iii. fig. 2. 

 2 Tom. i. p. 256. 



^ Tilesius, Mem. de rAcad. Imperiale 

 dcs Sciences de St.-P^tersbourg, tom. v. 



p. 452. 

 * Osi 



Foss. tom. i. pp. 11 and 225. 

 Sic in orig. 



