f 



ELEPHANT AND MASTODON. 97 



In the lower jaw, the first, or antepenultimate true molar 

 (being thefourth in the order of antero-posterior succession), 

 like the milk molar which precedes it in position, has a crown 

 composed of three ridges, with a hind talon of two tubercles. 

 In a detached Gers specimen from M. Lartet, which is con- 

 siderably advanced in wear, it measures 4 inches in length, 

 by 2 of width in front, and 2-4 behind. It differs from 

 the corresponding tooth of the upper jaw chiefly in the talon, 

 and in being broader behind than in front ; the reverse of 

 which takes place in the upper. This dilatation of the pos- 

 terior part is very constant in all the lower molars of M. 

 ancjustidens except the last. M. de Blainville refers to this 

 character in describing the third lower molar in this species 

 as being somewhat ' en forme de gourde.' • 



The second, or penultimate, occurs in situ along with the 

 third in the fine lower jaw figured by M. de Blainville, ^ 

 belonging to the Tournans cranial specimen previously 

 referred to. The penultimate on both sides, in this case, 

 is very much advanced in wear, the ridges being abraded 

 down to the common base of ivory, so that the discs are 

 partly confluent ; but the division of the crown into three 

 segments is distinguishable. This tooth on the left side 

 measures 4 inches long by 2*5 in width. Another example 

 of the same tooth is presented by a fine Gers fragment from 

 M. Lartet, comprising the anterior part of the left half of the 

 lower jaw of an adult individual. It is well advanced in wear, 

 but the discs of the crown afford distinct evidence of a 

 division into three ridges. There is an ill-defined basal 

 collar along the outside of the two posterior ridges, which 

 sweeps around the last so as to form a small terminal talon. 

 This tooth is considerably broader behind than in front, the 

 dimensions being— length, 4-5 in. ; width in front, 2-25, and 

 behind, 2-63 inches. This specimen corresponds very closely 

 in size, age, mineral condition, and external character gene- 

 rally, with the palate specimen, also from M. Lartet, which 

 furnished tlie first illustration of the last molar, along with 

 the penultimate of the upper jaw ; and it is not improbable 

 that they may have been derived from the same individual. 

 Several other examples might be quoted in proof of the con- 

 stancy of the ternary division of the crown, and of the rela- 

 tive proportions in this tooth. Among these is the Simorre 

 specimen figured by Cuvier,^ which is composed of three 

 ridges and a talon of two tubercles ; the dimensions being — 

 length, 4-5; width in front, 2; and behind, 2-55 inches. 



' P- 299. 3 Oss. Foss. tab. i. fig. 4. 



OstSographie, pi. xiv. and xv. 

 VOL. I. H 



