64 PACHYDERM ATA. 



of lab. 1. of von Meyer's memoir. The crown has the same three- 

 ridged form as the Sansans specimen, with which it agrees very 

 closely in dimensions, being 4.2 inches long, by 2.7 in width. 

 Von Meyer refers it with doubt to the third molar of the 

 lower jaw, right side of this species, while Kaup assigns to it 

 the same position in the lower jaw of his M. longirostris (loc. 

 cit. p. 81). 



The penultimate, or second true molar, is shown in situ along 

 with the last, in another instructive Gascon specimen from M. 

 Lartet, displayed in the Paris Museum. This fragment, likewise, 

 is of the left side of the upper jaw. Of the two teeth which it 

 contains, the anterior (or penultimate) had been a long time in 

 use, and is very much worn. It is nearly rectangular in form, and 

 the crown is distinctly divided into three discs, which indicate the 

 same number of ridges. No back ' talon' is distinguishable, the 

 abrasion of the last ridge being far advanced. The dimensions of 

 this tooth are 4.5 inches long by 2.75 of width in front, and 2.6 

 behind. It is described by M. de Blainville as the fourth, or ante- 

 penultimate. 1 The posterior tooth in this specimen, being the 

 third, or last true molar, like its equivalent in M. Ohioticus, is 

 more complicated in form than the two which immediately precede 

 it. The crown consists of four ridges, each composed of two pairs 

 of confluent points, arranged somewhat alternately, and there is 

 no distinct heel ridge appended to the posterior extremity. This 

 tooth is wide in front, and contracts very considerably backwards, 

 a character common in most species of Mastodon, to the last 

 molar of the upper jaw. The dimensions are, — length 6.25 in. ; 

 width in front, 3.25 ; width behind, 2.25. The palaeontological 

 gallery of the Paris Museum contains numerous other specimens of 

 the last upper molar of M. angustidens, four of which, from 

 different localities, have been admirably figured 3 in the * Osteo- 

 graphie.' They all agree in having the crown invariably divided 

 into four ridges ; the only variety which they present being in the 

 greater or less development of the ' talon' appendage of the last 

 ridge. Of these, the superb Tournans specimen, 3 which comprises 



1 De Blainville, loc. cit. p. 296, pi. 15. fig. 4 b sup. A \ 



3 Ibid. fig. 5 a, b, c. d, sup. 3 Ibid. pi. 14. 



/ . 



