30 
INDIAN TERTIARY AND POST-TERTIARY VERTEBRATA. 
\ 
the penultimate upper molar, but a subsequent comparison with that description lias 
shown that it is really the same.^ A comparison with the figure of m. 2 given in 
plate XXXVA. of the first volume, will show that it is really the first upper true 
molar of the left side. Nothing need be added to Falconer’s description, excej^t that 
traces of cement are to be seen in the transverse valleys ; and that the columns are 
relatively higlier than in M. angustidens, and the enamel is thrown into vertical 
corrugations. ■ The length of the specimen is 4, and its extreme width 2'5 inches. 
In pi. XXXII., fig. 4, of the first volume of this work a much-Avorn upper true 
molar of a trilophodont mastodon from the Punjab, is figured as m. 1 of M. falconer 
although it was noticed^ that it differed from the other true molars of that species in 
having irregular, instead of trefoil-shaped, dentine islets. It now appears from a 
comparison with the figure of m. 2 of it/, pandionis given in plate XXXVA.^ of the 
same volume, as Avell as from the crenulated edges of the enamel, the obliquity of 
the valleys, and the forward inclination of the ridges in the much-worn molar, that 
the latter should likewise be referred to M. pandionis ; of Avhich it is ui. 1 . It differs 
widely from the specimen noAV regarded as ni. 1 of J\I . falconerd ; in which species the 
enamel of the true molars is smooth,® the columns of the ridges nearly upright, and 
the valleys run straight across the crown. 
First loioer true molar. — The specimen rejDresented in plate V., figs. 1, la, was 
obtained by Mr. Blanford from Dera Biigti ; and from its narrow shape and the 
three ridges borne on the crown is evidently the lower molar of a trilophodon, 
belonging to the left side of the jaAV. The croAvn is still in germ, being untouched 
by wear ; and has lost a small ^^ortion of its joostero-external angle. The columns 
of the ridges and talons are taller than in the first and second lower molars of 
M. angusiidens (pi. IV., figs. 7, 8: pi. V., figs. 3, 7); and the transverse valleys are 
narrower and more blocked. The accessory columns are, moreover, much more 
numerous ; and consist of a confused agglomeration in each transverse valley, instead 
of a pair only : there is also an extra one of these columns Avedged in between the 
hind talon (ta) and the outer column of the last ridge. The enamel, instead of 
being smooth as in M. angusiidens, is thrown into vertical corrugations ; Avhich in a 
Avorn condition Avould give a crenulated appearance to the rings of enamel surround- 
ing the dentine islets. From the appearance of the enamel in the valleys it seems 
probable that cement Avas originally present in considerable quantities. The length 
of this specimen is 4T, the extreme Avidth 2-25, and the height of the inner column 
2'0 inches. 
1 The identification was not easy to make without a comparison of the actual specimen with Falconer’s description. 
2 Supra, vol. T., p. 208, note. 
3 This specimen was obtained after the smaller tooth had been described and figured : and exhibits more clearly than 
previous specimens the corrugated enamel as a well-marked specific character. In describing it at the end of the first volume 
the writer was on the point of departure for the field, and had not time to make a full comparison with other specimens ; 
which would have shown that the smaller tooth belonged to the same species. 
4 Vol. I., pi. XXXIII., fig, 3. 
5 The milk-molars with rough enamel figured in vol. I., pi. XXXII., and referred to If. /afcojim will be aUuded to 
under the head of that species. 
