253—72 
SIWALIK AND NAEBADA PEOBOSCIDIA. 
of the same plate there is another specimen of the same tooth which has five 
ridges and a talon. Its length is 6’5 inches and its width 2’9 inches. 
In the palate specimen figured in Plate XXXIV, fig. 1, of the “ Pauna An- 
tiqua Sivalensis,” containing the secoijd and third true molars, the former tooth 
has four ridges and a talon, and has a length of 4' 7 inches and a width of 2' 8 
inches. A very similar palate in the Indian Museum also shows the second true 
molar with four ridges and a hind-talon. 
The number of ridges in this tooth may, therefore, be four or five. 
Second lower true molar. — There is no complete specimen of the second 
lower true molar of this species either in the collection of the Indian Museum, 
or among the series figured in the “ Pauna Antiqua Sivalensis.” The imperfect 
specimens, however, seem to indicate that this tooth, in some instances, carried five 
ridges. 
A specimen of the homologous tooth in the Museum of the College of Sur- 
geons, referred to by Palconer in a note (2) to the description of Plate XXXVII 
of the “ Pauna Antiqua Sivalensis,” has only four ridges and a talon. 
This tooth, therefore, like the corresponding upper molar, may have either four 
or five ridges. 
Third upper true molar, — In fig. 6 of Plate XXXVI of the “ Pauna An- 
tiqua Sivalensis” there is represented a complete last upper true molar of Mastodon 
sivalensis. This tooth has six ridges and a hind-talon, and a length of 7'8 inches 
and a width of 3 ‘3 inches. It has the alternate arrangement of the columns 
very conspicuously displayed. 
In the palate specimen represented in fig. 1 of Plate XXXIV of the same 
work, the last molar has five ridges and a hind-talon. On this tooth Dr. Palconer 
remarks : — 
“ The front ridge has two confluent ridges on the outside, to the inner of which 
tlie intermediate pillar is attached, joining on with ' the innermost large point of 
the third ridge. This third ridge shows but one thick point on the inner divi- 
sion, and two on the outer, with the intermediate pillar connecting the outer 
division of the third with the inner division of the fourth ridge, and so with the 
last ridge. This diagonal connection of the posterior surface of the outer division 
with the anterior surface of the inner points of the next following ridge causes 
in wear the alternate-like discs of detrition, which characterize the teeth of Masto- 
don sivalensis^^ 
In fig. 1 of Plate XLIV of this memoir, there is drawn a very fine specimen 
of an almost unworn last upper molar of a Mastodon, taken from the left side 
of a palate specimen collected by Mr. Theobald in the Siwahks of the Punjab ^ 
It is inferred to belong to M. sivalensis from its narrowness, general complexity 
of pattern, and somewhat alternate arrangement of the columns, though this latter 
character is not so well marked as in Palconer’s specimens. The tooth is preceded 
in the palate by a much worn and smaller tooth, in which the number of ridges 
