60 PACHYDERMATA. 



rence in the fossil state, the available materials for tracing the 

 dentition of this species are less numerous and complete than in 

 the case of M. Ohioticus. The following descriptions are chiefly 

 derived from specimens in the Paris Museum, the most of which 

 have been figured by M. de Blainville. 1 Of the milk or deciduous 

 molars in the upper jaw, the third only has yet been met with, in 

 situ, in the palate. It is well shown, on the right side, in the pos- 

 terior tooth of the Dax specimen figured by Cuvier (Oss. Foss. 

 pi. 3. fig. 2.), and referred to above, the crown consisting of three 

 transverse ridges, and an accessory talon of two tubercles, each of 

 the ridges being composed of two pairs of confluent mammilla?. 

 A single tubercle juts out into each of the hollows between the 

 ridges alternately with the principal points, causing the trefoil- 

 shaped discs, which the worn teeth present in this species, so dif- 

 ferent from the lozenge-shaped discs of M. Ohioticus. The 

 dimensions of this tooth are not mentioned by Cuvier, but it may 

 be gathered from the context of his description, that it measured a 

 little above three inches long by about two in width. The same 

 tooth, of the left side of the upper jaw, is seen in a most instruc- 

 tive specimen found by M. Lartet, near Sansans, in the depart- 

 ment of Gers, containing two molars in situ, both of which are 

 three-ridged. Of these the anterior, which is the third milk molar 

 corresponding with the Dax tooth, is in an advanced stage of wear, 

 the ridges of the crown being ground down into three disc sur- 

 faces. No back talon is distinguishable ; if originally present, it 

 has merged into the wear of the last ridge. This tooth measures 

 3.15 inches long, by two of width in front, and 1.75 behind, 

 narrowing a little towards the posterior end. It is figured by M. 

 de Blainville. 2 The same collection possesses another detached 

 specimen from M. Lartet, of exactly the same size, but less worn, 

 which shows three distinct ridges, and a small subordinate talon. 

 The grinder described and figured by von Meyer, in his memoir 

 on the fossil remains of Georgensmiind (p. 38, tab. 2. fig. 7.) 



1 One of the authors, during a visit to Paris, had the freest access to these specimens, 

 by the liberal permission of MM. de Blainville and Laurillard. H. F. 

 a Osteographie, pi. xv. fig. 3 c sup. 



