ELEPHANT AND MASTODON. 107 



of the grinders, equally constant with those which have been 

 shown above to hold in the section TrilopJwdon : a quaternary 

 division of the crown being presented by every tooth in 

 which a ternary arrangement occurs in the latter. This 

 section, so far as it is known to us at present, comprises foiu- 

 fossil species, two of which are European and two Indian. 

 The two former have hitherto been confounded together by 

 most authors, as well as with M. angustidens. Their accurate 

 discrimination is of great importance, as they appear to 

 belong to faunas of two distinct periods. 



M, longirostris. — The materials requisite to illustrate the 

 dentition of this species, thanks to the indefatigable re- 

 searches of Dr. Kaup in the fossiliferous sand of Eppelsheim, 

 are as complete as in the case of M. Ohioticus. The series 

 of teeth is beautifully represented in the ' Ossemens Fossiles 

 de Darmstadt.' There were three deciduous molars in the 

 upper jaw ; of these, the antepenultimate or first (theoreti- 

 cally the second) is of an oblong form, broader behind than 

 in front, consisting of two ridges disposed in four points ; 

 the dimensions being about 1-2 inches long by 0*9 inches 

 broad. The second or penultimate milk molar is composed 

 of three principal ridges, with an obscure talon crest behind, 

 measuring 2 inches long, by about 1"4 of width in front, and 

 1-6 inches behind. The third or last milk molar has a crown 

 composed of four transverse ridges, with an accessory crest 

 in front, and a talon ridge behind. A sinuous longitudinal 

 channel bisects the crown, along the axis, into an outer and 

 inner division, as in the North American Mastodon, each 

 division of the ridges presenting a finely lobed or denticulated 

 edge, composed of from four to five minute points. These 

 edges are gradually depressed from either side towards the 

 centre, so that they unite at a very open angle. The anterior 

 crest is given off from the principal point of the inner side of 

 the first ridge ; it descends obliquely outwards to the base of 

 the outermost point, and is thence reflected backwards in a 

 basal collar, bounding the inner side of the crown. There is 

 no corresponding collar along the outer side. The valleys 

 are transverse, but their continuity across is somewhat 

 interrupted by small mammillEe near the axis, which form a 

 sort of bridge between the contiguous ridges. These charac- 

 ters are minutely and carefully described by Von Meyer. 

 This tooth measures 2*7 inches long by about two inches 

 broad. For the determination of these teeth we have had 

 access to the origmal specimen, now in the possession of the 

 Earl of EnniskiUen, figured by Kaup (PI. XX. fig. 2),' and to a 



' Also figured in Fauna Antiqua Sivalensis, PL xl. figs. 6 and 6 a.— [Ed.] 



