612 MR. C. FORSTER COOPER ON MIOCENE 



In connection with these palates, the third upper molar (PI. I. 

 fig. 1) may be desciibed, of which there are two separate speci- 

 mens, a right and left, both unworn and of similar pattern. 

 They difler in shape from corresponding teetli from France in 

 the collection of the British Museum in being, broad in front and 

 in getting narrow behind so rapidly that the ground-plan of the 

 tooth is that of an isosceles triangle instead of the more usual 

 elongated form. 



A tooth figured by Schlesinger * (var. subtapiroidea) is ap- 

 parently nearer tiie present one in shape, but, being tilted up in 

 the figure, his specimen cannot be closely compared. In structure 

 the two are very similar, except that in the Indian specimens the 

 fourth ridge (talon) consists of three cusps only instead of four, 

 and that anything in the nature of valley cusps is conspicuous by 

 its absence. In Schlesinger's form the cusps of the main ridges 

 are three on each side, except on the last ridge where they are 

 double only; in the present form they are partly double, but 

 here and there show either the treble condition or the beginning 

 of it. In his form, however, there is a pair of accessory cusps 

 which, while not very conspicuous, can be seen clearly in the 

 first two valleys. These are absolutely unrepresented in the 

 Indian form, with the sole exception of the fii'st valley in one of 

 the two teeth, which has a low but distinct cusp on the outer 

 side connected to the posterior flank of the first ridge. It is 

 possible that the " subtapiroid '*' condition is the more primitive, 

 and small mutations in the direction of greater complication of 

 the valleys are therefore to be expected. 



These third upper molars, while nearly as broad as Schlesinger's 

 specimen, are shorter, and are considerably more so than French 

 specimens. 



Another separate upper tooth, in quite unworn condition, is 

 here figured (PI. I. fig. 2). It is apparently a second molar of 

 the left side, but is rather larger than the corresponding teeth 

 in the two palates already described. It is similar to them in all 

 respects, except that the aix^angement of the cusps is much more 

 that of the " typica" form. This is especially noticeable in those 

 of the inner side and on the second ridge, where as many as 

 eight cusps of diflferent sizes can be counted. At first sight this 

 tooth might be mistaken for a very small third molar on account 

 of its rather pointed end, large talon, and absence of posterior 

 pressure mark. If this were really so, it might have some bearing 

 on Pilgrim's genus Hetn'miastodon. The pointed appeai^ance is 

 due to the thick enamel being broken away on each side, and is 

 therefore purely artificial ; if this part be restored, the tooth has 

 the square end of a second molar. The large talon is due to the 

 tooth being in germ and becomes resorbed when the third molar 

 begins to press against it ; in each of the two palates in which the 

 third molar is not yet in contact with the second the latter hns a 



laro-e talon. 



o 



* Sclilesinger, loc, cit. pi. vii. fig. 3, 



