221—40 
SIWALIK AND NARBADA PROBOSCIDIA. 
In fig. 1 of the fortieth plate of the “ Eanna Antiqna Sivalensis,” there is 
figured a tooth-germ which, except in being shghtly smaller, agrees in all respects 
with the present specimen, and which is probably the corresponding tooth of the 
opposite side of the jaw. The description of the specimen as given by Ealconer is 
as follows: “Eigs. 1 and la. — Mastodon latidens. Second (?) upper milk-molar 
with two ridges, Length 1‘9 inches, width 1*4 inches.” Now, it is quite clear that 
the specimen cannot belong to Mastodon latidens, as the corresponding tooth of that 
species (Plate XXXVII, fig. 4) has three transverse ridges, which are very much 
lower, and the valleys are open and without cement. I shall again have occasion to 
refer to this question when I come to consider the second upper milk-molar of the 
latter species. 
The present tooth has a considerable general resemblance to the corresponding 
tooth of Mastodon angustidens ^ (with which species M. pandionis seems to be closely 
allied), but is distinguished by the greater extent to which the transverse valley is 
blocked, and by the smaller size of the hind talon as well as by the generally larger 
size of the tooth. 
Last lower premolar and second loioer milk-molar . — The small specimen re- 
presented in fig. 2 of Plate XXXY is evidently either the second (penultimate) 
lower milk-molar, or the last lower premolar of a trilophodont Mastodon ; it is 
similar to a tooth formerly in the j)ossession of Ealconer, and by him classed as the 
last lower premolar of M. pamdionis, and is also very similar to the tooth generally 
classed as the last lower premolar of M. angustidens, from, which I think thnt 
Ealconer was probably right in referring his specimen to 31. pandionis. As both the 
second milk-molar and the last premolar of Trilophodons have only two ridges it is 
extremely difficult to assign either of these teeth, when found isolated, to its proper 
serial position: I shall, however, show why I class the figured tooth as the latter. This 
tooth belongs to the left ramus of the mandible ; its crown is elongated antero- 
posteriorly and is somewhat narrower in front than behind. This specimen, together 
with a slightly smaller but similarly shaped tooth, was obtained by Mr. W. T. Blanford 
in Sind. The smaller specimen shows very distinctly small discs of pressure on both 
the anterior and posterior surfaces, proving that the tooth when in position had 
another tooth on either side of it in close apposition : the figured tooth has only a 
disc of pressure posteriorly, showing that the preceding tooth must have dropped 
out at an early period. As the two teeth are precisely similar there cannot be the 
least doubt but that they are homologous. 
This tooth, as we have seen, carries two complete transverse ridges, and small 
fore-and-aft talons, a wide and nearly open valley separating the two ridges. Both 
ridges are considerably worn, the plane of wear of the first being nearly horizontal, 
while that of the second is directed obhquely forwards. In the centre of the valley, 
between the two ridges, there is a small circular disc of dentine exposed, which is 
formed by the abrasion of one of the ridges of the corresponding upjoer tooth 
' Gaudrj’ : “ Les Euchainements du Monde Animal,” Mammiferes Tertiaires, p. 180, fig. 239. 
