215—84 
SIWALIK AND NAEBADA PEOBOSCIDIA. 
The first specimens we have to consider are the two lower molars represented 
in Plate XXXIV. These two specimens are associated molars from the right ramus 
of an incomplete mandible collected hy Mr. Theobald at Halwar ih the Punjab. 
Since the smaller of the two teeth (fig. 1) carries three ridges and a hind-talon, 
wliile the larger and succeeding tooth (fig. 2) carries four ridges and a double hind- 
talon, or perhaps five ridges, it is evident that the two teeth are respectively the 
second and third true molars of a trilophodont Mastodon. The smaller tooth is in 
an intermediate state of wear, while the larger tooth has only its first and second 
ridges slightly touched hy wear, the remaining three ridges having been still con- 
cealed hy the gum at the death of the animal to which the jaw belonged. As I 
have said, the smaller tooth consists of three complete transverse ridges and a large 
hind-talon ; each of these ridges when not too much worn away, as is shown in the 
third ridge, is divided into an inner and an outer portion by a median longitudinal 
cleft. The summit of each of these two portions of the transverse ridges, when 
worn down, exhibits irregularly shaped discs of dentine, which never assume a 
trefoil figure, and by which character the molars of this species are at once distin- 
guished from those of Mastodon falconeri. In the transverse valley between each 
pair of ridges, there are two or more accessory tubercles or columns, wedged in 
between the main ridges, completely blocking the valleys, almost as high up as 
the summits of the ridges, as is shown in the larger and less worn tooth. The inner 
and outer columns of each transverse ridge are placed somewhat alternately to one 
another, the centre of the inner column of each ridge being slightly in advance of 
the centre of the outer column. The hind-talon of the smaller tooth is of unusually 
large size, and, like the true ridges, consists of an inner and an outer column, 
separated by a median longitudinal cleft, and having two accessory columns in 
the preceding transverse valley. The talon is distinguished from a true ridge by 
being much narrower ; it is probable, however, that we have here (as in the suc- 
ceeding tooth) a molar indicating the transition from a Trilophodon to a Tetra- 
lophodon. In the two anterior ridges of the penultimate tooth the exposed dentine 
discs of wear have united, hut there is still in both a large trace of the median 
cleft. 
The larger and nearly unworn tooth (fig. 2) shows the terminations of each 
column more distinctly ; but these columns have precisely the same arrangement 
as in the smaller tooth. There is an anterior talon consisting of four agglomerated 
columns, and a large double hind-talon.' The columns of the transverse ridges are 
of great vertical height, and at their summits curve towards the anterior extremity 
of the tooth. The valleys contain a considerable quantity of cement, which extends 
to within half an inch of the summits of the columns ; this cement appears to be 
loosely attached, and to fall off as the teeth are worn down. It, however, exists in all 
the specimens of unworn molars, which are contained in the collection of the 
* Tlie anterior part of this talon might almost be countec as fifth true ridge, but it will be seen to correspond with 
the hinder part of the smaller tooth, which is evidently a talon. 
