SIWALIK AND NADBADA PEOBOSCIDIA. 35—216 
Indian Museum, and may therefore he considered as characteristic of the species. 
The dimensions of the two figured teeth are as follows : — 
Length of second true molar . 4-1 
Width of ditto ditto 2-6 
Length of third ditto . .7-4 
Width of ditto 
Height of ridges in ditto 2-9 
Comparison . — If the description of these two molars he compared with fal- 
coner’s description of the upper molar of Mastodon pandionis, and with the figure 
of the unworn upper molar, represented in figs. 6 & 7 of Plate XXXIV, of the first 
volume of the “ Palaeontological Memoirs,” it will he evident that aU these three 
teeth have the same general characters, viz., very high and alternately arranged 
columns in the transverse ridges, and the transverse valleys completely blocked hy 
outlying columns from these ridges. There appears, indeed, from falconer’s descrip- 
tion, to he a somewhat greater complexity in the arrangement of the outlying 
columns in the upper molars than there is in the lower molars. AU the other charac- 
ters of the teeth are, however, so exactly similar, that there is every prohahility of 
theu having belonged to the same species, and I have accordingly referred them aU 
to Mastodon pandionis. The molar figured in the “ Palseontological Memoirs,” 
considered by Dr. falconer to he the first or antepenultimate true molar, has a 
length of 4 and an extreme width of 2’5 inches ; these dimensions are very nearly 
the same as those of the second or penultimate lower true molar from the Punjab ; 
as wiU he seen subsequently, however, there is some considerable variation in the size 
of the molars of this species. 
Form of mandible . — The portion of the mandible to which the two figured 
molars belong, comprehends the greater part of the horizontal ramus of either side ; 
posteriorly each ramus is broken off at the hinder end of the alveolus of the last 
molar, and anteriorly a short distance in advance of the penultimate molar. The 
inner surface of the ramus is convex from above downwards, and the outer concave, 
the inferior border being slightly sinuous : the angle included between the inferior 
and alveolar borders is an acute one, the bounding lines receding from one another an- 
teriorly, and the jaws consequently becoming deeper towards that extremity. The 
whole ramus is much compressed from side to side, the vertical diameter being much 
greater than the horizontal. The ramus is continued in the same line as the alveo- 
lar border up to the point where it has been broken off in front ; at the fracture 
the depth of the sides of the mandible is close on 8 inches ; the jaw presents in 
section at this point a U-shape, the base of the JJ being thick, and the sides very 
thin, and tapering to a sharp edge at their summits. The form of this transverse 
section, together with the direction of the upper and lower borders of the ramus, 
shows that the mandible when complete would have been produced into a long 
trough-hke symphysis, and could not ha’ve had a short symphysis like that of the 
living Indian elephant. We shall subsequently describe a specimen showing this 
