SIWALIK AND NARBADA PROBOSCIDIA. 
55--236 
equal-sized transverse ridges, and a smaller row of cusps representing a third 
ridge posteriorly. The two main ridges are divided by a median cleft, and are 
low and straight, and the valleys are open and uninterrupted. The length of 
this tooth is 2-2 inches, and its greatest width 1-8 inches. Two very similar, 
but worn specimens, of the same tooth are contained in the collection of the 
Indian Museum. This tooth is of great importance as proving the existence 
of premolars in the species. Since this tooth is so much smaller than the tooth 
which it succeeds (Plate XXXVII, fig. 8), it is quite clear that when protruded, 
it could not have touched the teeth on either side of it, and probably stood quite 
isolated, as the corresponding tooth of M. pei'imensis represented in Plate XL. 
Penultimate upper premolar.— Tho, next specimen (Plate XXXVII, fig. 7) was 
also obtained from the Punjab. This tooth has no disc of pressure on either side • 
from its form it might be either the first upper milk-molar or the penultimate pre- 
molar of a Tetralopliodon, or the second upper milk-molar or last premolar of a Tri- 
lopJiodon. The absence of any disc of pressure in front shows that it cannot be the 
second milk-molar of a Triloplwdon, while its large size and absence of posterior disc 
of pressure shows that it cannot be the first milk-molar of a Tetralopliodon. 
Among the Tetralophodons, M. latidens and 31. perimensis are known to have been 
furnished with premolars, and it is, therefore, very probable that the tooth is the 
penultimate upper premolar of one of those species. As the tooth has low ridges, I 
have thought it not improbable that it belongs to the former species, though I cannot 
be at all positive in this determination. The tooth is considerably worn down, and 
has an irregularly oval-shaped crown, somewhat narrower in front than behind. It 
carries two low and broad ridges, closely approximated externally, and a small hind- 
talon. The side of the ridges on the lower border of the figure is the most worn 
showing that this border is the inner side of the tooth, which must consequently 
belong to the right side of the maxilla. The transverse valley is not very distinct, 
which might lead to the belief that the tooth does not belong to 3T. latidens. Pre- 
molars, however, not unfrequently vary somewhat from the type of the other teeth. 
The length of the specimen is 1-6 inches, and its greatest width 1-4. Another very 
similar specimen, also from the Punjab, is in the collection of the Indian Museum. 
General characters , — Having now passed in review the molar series of Jf, lati- 
dens, we may sum up what is known regarding the species. The adult cranium is 
unfortunately quite unknown ; the palate is noticeable from the extent to which the 
molars converge anteriorly. The mandible is known by a specimen of the greater 
part of the right ramus, containing the two last molars, in the collection of the 
Indian Museum. This mandible is very long and slender, and sub-circular in cross- 
section, in the middle its vertical diameter at the penultimate molar being 5‘8 inches 
and its transverse diameter 5'6. inches. The lower border is nearly straight up to the 
symphysis, with a slight convexity in the middle. Prom the extremely small size and 
circular section of the ramus where broken off at the commencement of the sym- 
physis, the latter must have been short, and was probably unprovided with incisors. 
