XVI. 
INDIAN TERTIARY AND POST-TERTIARY VERTEBRATA. 
have no appreciable quantity of cement in the valleys, and when worn [supra vol. I. 
pi. XL.) present trefoils on their inner columns. 
Contrasting these teeth with those of M. latidens, of which species typical 
examples of the milk-molars are figured in vol. I. pi. XXXVII. of the present work^, 
while typical true molars are figured in pis. XXXVIII. and XXXIX. of the same 
volume, in pi. XXXI. figs. 3^, 4, 5 of the “ Fauna Anti qua Sivalensis,” and in pi. 
XLVIII. of the ‘ Proc. Zool. Soc.’ for 1885 (the latter figure being reproduced on a 
smaller scale in woodcut fig. 7), it will be seen that the ridges in the latter species 
are much lower, placed closer together, and have a less distinct median longitudinal 
cleft ; while there are no distinct accessory tubercles, and the valleys are consequently 
almost completely open : when worn [supra vol. I. pi. XXXVIII. fig. 2) the inner 
columns present very imperfect trefoils, and the dentine surfaces of the inner and 
outer columns soon unite to form a single transversely elongated surface. The third 
true molar (woodcut fig. 7 ; see also “ F.A.S.” pi. XXXI. figs. 3, 3a, supra vol. I. 
Fig. 7. Mastodon latidens. The third left upper true molar of a small individual in a partially -worn condition ; 
from the Pliocene (?) of Borneo, f. The lower border of the figure is the inner border of the specimen. 
(Eeduced from the figure in the ‘ Proc. Zool. Soc.’ 1885, pi. XLVIII.) 
pi. XXXIX. ‘ Proc. Zool. Soc.’ 1885, pi. XLVIII.) is very wide, tapers but little 
posteriorly, and carries five ridges and a hind talon, the latter being always large 
and frequently very wide (compare woodcut fig. 6). All the teeth are of great 
relative width ; and pm. 4 [supra vol. I. pi. XXXVII. fig. 6) differs markedly from 
the homologous tooth of M. cautleyi [supra vol. I. pi. XL.) 
Turning now to M. perimensis (with which the writer previously associated two 
of the type molars of the new species) it will be seen that here also decided dis- 
tinctions obtain. A typical example of the second left upper -true inolaF of this 
species in an unworn condition is represented in woodcut fig. 8, in which the summits 
of the columns of the first ridge are broken off ; while other typical upper molars 
are represented in the “ F.A.S.” pi. XXXI. figs. 9, 9a, in Falconer’s “ Palaeonto- 
logical Memoirs,” vol. I. pi. IX. figs. 3-6 (the one represented in figs. 5, 6 is the 
right m.2 , which agrees precisely with the one figured in the accompanying woodcut 
1 In the first volume the normal three milk molars of the Proboscidea are termed mm. 1, mm. 2, and mm. 3. 
2 The teeth in this (the type) specimen are ia-2 and m.S , but are wrongly described in the index to the plate. 
3 See ‘ Cat. Siwalik Vert. Ind. Mus.’ pt. I. p. 97. No. A. 355. (1885). The specimen is there referred to the right side. 
