SIWALIK AND NARBADA PROBOSCIDIA. 
59—240 
(‘xtreme smoothness and j)olished state of the enamel, I have thought that the 
specimen should very probably he referred to Mastodon perimensis, the teeth of 
which present that character to a very noticeable extent. The tooth belongs to the 
right side of the jaw, and is rudely oval in outline, the posterior border, however, 
being nearly straight. The crown bears two ridges, the hindmost of which is acute 
and wedge-shaped, and is partially divided by a slight cleft into two columns. The 
anterior ridge forms a large blunt cone, the summit of which has been largely worn 
away. A longitudinal ridge on the inner side of the tooth connects the fore-and-aft 
ridges ; there is no trace of any talon. The absence of any talon, as well as the 
shape of the ridges, at once distinguishes this tooth from the corresjionding milk- 
molar of Mastodon latidens, which has already been described. The length of the 
specimen is 1'3 inches, and its greatest width I'l inches. 
Last upper premolar and first true molar. — The fragment of the left maxilla 
of a Mastodon containing two teeth, which is represented in Plate XL, was also 
obtained during the winter of IS'ZS by Mr. Theobald in the Siwaliks of the Punjab, 
and has already been shortly alluded to at page 45 of the twelfth volume of the 
“ Records.” The larger tooth carries four transverse ridges on the crown, and very 
small fore-and-aft talons : the fourth ridge is smaller than either of the others, and 
is considerably curved. The tooth has not been much used, and the rate of wear is 
very unequal on the two sides of each ridge, the inner column showing a large 
surface of dentine, while the enamel of the outer column is still imperforate. The 
ridges are of considerable vertical height, and each is divided into two portions by 
the cleft wdiich traverses the longitudinal axis of the tooth. The portion of each 
ridge on the outer side of this cleft consists of two agglomerated tubercles ; while 
the portion on the inner side consists of one large column or tubercle in the line of 
the ridge, to the external extremity of which two smaller tubercles are closely 
attached, projecting on either side into the valleys, and uniting with the corre- 
sponding tubercles of the other ridges, thus obstructing the base of each valley. 
The arrangement of the accessory tubercles causes the worn dentine surface of each 
main column to form a trefoil-shaped islet, as is shown in the first ridges. Very 
slight tubercles occur at the inner extremities of the transverse valleys. The 
enamel is somewhat corrugated, and there are some slight traces of cement in the 
valleys. 
The anterior surface of the tooth presents a large flattened and smooth disc, 
produced by the pressure of a preceding tooth, which must have been in apposition 
with it. 
The smaller tooth, which has a sub-circular crown, is entirely unworn, and had 
not perforated the gum at the death of the animal. The summits of the crown of 
this tooth are nearly on a level with the base of the crown of the larger tooth. The 
smaller tooth is placed on the anterior side of the larger. The position and condition 
of wear of the smaller tooth, show that it must be a premolar, and that it has vertically 
succeeded a worn-out milk-molar, which produced the facet on the anterior surface 
