44 FAUNA ANTIQUA SIVALENSIS. 
to their height; the ridges are less elevated, and consist of a greater 
number of coronal points, and the valleys are more open and trans- 
verse (or interrupted only by an insignificant number of warty tuber- 
cles) than in M. Sivalensis. 
Figs. 9 and 9 a.—Mastodon Perimensis (Fale. and Caut.). From 
Perim Island. Portion of upper jaw, right side, with molar, present- 
ing characters similar to those of M/. Sivalensis and M. Arvernensis. 
—B.M. 
Length, 6°3 in. Width, 3°3 in. 
Figs. 10 and 10 a.—M. Perimensis. Portion of lower jaw, left side, 
with penultimate and last true molars. Presented by Miss Pepper to 
B.M. 
Length of anterior molar, 4:8 in. Width, 2°6 in. Length of fragment of 
posterior molar, 2°1 in. Width, 2°8 in. 
Figs. 11 and 11 a.—Fragment of lower jaw, with molar. 
Length of tooth, 8-4 in. Width, 3°6 in. 
PLATE XXXII. 
Mastodon Sivalensis (Fale. and Caut.). From the Sewalik hills; 
anterior view. Three other views of same cranium in Plate XXXII. 
The brow is a little crushed between the temporals. The left tusk- 
sheath is present, the right is withered; there is distortion of the 
tusk-sheaths in consequence. There is an enormous and _ peculiar 
projection of the lips of incisive anterior end of naso-maxillary fissure, 
so as to project over the trunk, or inter-incisive fossa. This fossa is 
very deep, enormously so. The depressions for the condyles of the 
lower jaw are very vaulted. There are two infra-orbitary foramina on 
the right side. The grinders are very much worn. On the left side 
there would be five ridges, with a very complicated heel-series. Pos- 
teriorly, the teeth show well the peculiar characters of Mastodon 
Sivalensis.—B.M. (Reproduced in Plate X.) 
Extreme length from occipital bulge to tips of incisives, 28°3 in. Width of occiput, 
22°4 in. Height of occiput from plane of condyles, 19:0 in. Interval between 
outer edge of condyles, 66 in. Vertical diameter of occipital condyle, 4:0 in. 
Transverse diameter occipital condyle, 2°7 in. Width of base of occiput, 21:0 in. 
Transverse diameter occip. foram. 2°9 in. Vertical diameter occip. for. 2°5in. From 
occiput to broken tips of nasals,14-0in. From occiput to anterior margin of orbit, 
21:0 in. From anterior margin nasal opening to the tips of the incisive, 14:0 in. 
Width of brow between post-orbitary processes, 25°56 in. Width at contraction 
between temporals, 11°6 in. Width of naso-maxillary (trunk) opening, 12:0 in. 
Depth of naso-max. op., lateral, 3-0 in. Vertical diameter orbits (nearly circular), 
4°3 in. Transverse diameter orbits, 4°3 in. Interval between orbitary processes 
of one orbit, 2°7 in. Width of forehead at anterior margin of orbit, 20°6in. Con- 
traction of muzzle at orbitary foramen, 13°0 in. Depth of trunk fossa below brow, 
9°8 in. Greatest interval between zygomatic arches, 22-0 in. From base of 
zygomatic to top of occiput, 20°56 in. Depth of anterior orbitary process of 
maxillary, 4:5 in. Height of skull from palate to top of occiput, 25°0 in. From 
posterior surface condyles to posterior surface palate, 16°0 in. From pterygoid 
processes to anterior margin of palate, 12°2in. Height of pterygoid, 10°3in. Distance 
from molar to posterior surface of pterygoid, 4:2 in. Width of pterygoid above, 6:0 
in. Width of pterygoid below, 7°5 in. Width of fissure (between pterygoids), 2°3 
in. Length of palate at middle, 9°6in. Width of palate between molars in front, 
2:8 in. Width of palate between molars behind, 2°6 in. Length of left molar, 7°8 
in. Width of left molar in front, 3:2 in. Width of left molar behind, 3°3 in. 
Length of articulating condyles for lower jaw, 4°8 in. Greatest width of condyles 
for lower jaw, 30 in. 
