245—64 
SIWALIK AND NAEBADA PROBOSCIDIA. 
figure of that specimen. Another last lower molar in a nearly complete mandible 
from tlie Punjab has a length of 10'7 inches, and a width of 4‘4 inches. 
Mandible. — In a notice published in the “ Records, I have recorded the 
acquisition by the Indian Museum of a complete specimen of the adult mandible of 
M. perimensis, obtained by Mr. Theobald in the Punjab. The specimen has not 
been figured here, owing to its very large size, and the consequent difficulty of 
getting an accurate drawing of it with the means at my disposal. The specimen 
shows the last true molar and a portion of the penultimate tooth. The ramus is 
sub-circular in cross section with a slight lateral compression ; it bulges out below 
the last molar ; the lower border of the ramus is very slightly convex posteriorly, 
and as slightly concave below the symphysis. The latter is produced into a short 
trough-like symphysis similar to that of the specimen represented in fig. 2 of 
Plate XLIII. In the figured specimen there is seen at the anterior fractured extre- 
mity, in transverse section, a pair of small incisors, with a pyriform section. In the 
complete mandible, of which the symphysis is entire, there are no incisors ; the 
figured specimen probably belonged to a male, and the other to a female. The 
dimensions of the complete mandible are as follows : — 
Length from hinder border of last molar to distal end of symphysis 29‘0 
Ditto from anterior border of penultimate ditto to ditto ........ 13'5 
Ditto of last molar 10'7 
Interval between condyle and coronoid process 6'0 
The form of the symphysis of the mandible is of itself quite sufficient to dis- 
tinguish M. perimensis from M, longirostris^ in which the symphysis is longer, 
wider, and more deflected, with a shallower spout. The lower border of the ramus 
of the latter is much bent, whereas that of the former is nearly straight. In 
M. longirostris there is a considerable lateral compression of the rami, totally 
wanting in M. perimensis. 
Undetermined mandible. — In , fig. 1 of Plate XLIII, I have had lithographed 
another symphysis of the mandible of a Mastodon^ bearing a considerable general 
resemblance to that of M. perimensis, but also presenting some points of difference. 
Its main point of difference is that in place of having a deeply hollowed spout-like 
symphysis, it has only a very slight hollowing out of the produced symjDhysis, and 
swells out anteriorly, while the symphysis of the typical tuskless form of M. peri- 
mensis (as shown in the large unflgured mandible) tapers somewhat more to a point. 
The trough in the latter mandible is, however, somewhat less deep than in the 
figured tusked specimen, and I am inclined to think that the specimen represented 
in fig. 1 must also be referred to a variety of M. perimensis. That specimen 
certainly cannot belong to either M. pandionis (Plate XXXVI fig. 1) or M. siva- 
lensis ; ^ its depth, when broken posteriorly, is too great to have fitted on to the 
> Eec. Geol. Surv. India, Yob XI, p. 71. 
^ “ Fauna Antiqua Sivalensis,” PI. XLV, fig. 10. 
» Ibid., PI. XXXV, fig. 1. 
