SIWALIK AND NAEBADA PEOBOSCIDIA. 
33—214 
usual, by an indistinct longitudinal cleft along the axis, marking off an outer and 
inner division. Each of the three ridges has the outer division simple, and composed 
of a thick conical transverse mass, the summit of which is somewhat compressed 
and indistinctly hi- or tri-lobed by corresponding longitudinal furrows. The inner 
division is more massive and complex, each ridge throwing out from its anterior and 
posterior surface — the former diagonally forwards, tlie latter diagonally backwards — 
a ‘ col ’ of robust tubercles, which meet in a chevron form in the middle of the valley, 
so that, when the inner division of the crown is regarded in plan apart from the 
outer, it presents, in conjunction with the outlying tubercles, a series of zig-zags 
closely resembling the letter W. The complexity of pattern is further increased by 
the salient apex of the connecting ‘ col ’ being continued outwards towards the margin 
in a single line of cylindrical mammillae, which completely obliterate the bottom of 
the outer half of each valley ; while the inner half, corresponding with the re-enter- 
ing angle between the large inner cones, forms a gorge which is entirely free from 
tubercles. The anterior talon forms a subordinate ridgelet, which is thrown off in 
the usual manner from the anterior portion of the inner cone, and is continued out- 
wards towards the margin, with less inclination downwards than is usually the case 
in the other allied species {M. angustklens.) It is composed of about four robust com- 
pressed tubercles, which are separated from the anterior ridge by a well-marked chasm. 
The posterior talon consists of a cluster of indistinct confluent tubercles thrown off 
from the posterior part of the inner tubercle of the last ridge, and so adpressed to the 
ridge that it does not yield the defined and separate appearance seen in the talon of 
Trilophodon angustidens. After a little wear the posterior talon would be involved in 
the disc of detrition of the last ridge.” 
Dr. Ealconer then proceeds to compare a small two-ridged tooth of 31. pandi- 
onis with a corresponding tooth of Jf. angustidens. I shall have occasion to refer 
to this tooth again in the sequel. 
Besides the two above-mentioned molars of 31. pandionis, there is a left an- 
tepenultimate upper molar of the same species in the British Museum, repre- 
sented on Plate XXXIV (figs. 6 and 7) of the first volume of the “ Palseontological 
Memoirs,” which was found in Dr. Ealconer’s private collection, the locality whence 
it was obtained being apparently unknown. Of this specimen I have obtained 
a cast for the Indian Museum through the courtesy of the Trustees of the British 
Museum. 
A short note on some lower jaws of this species was joublished by myself in the 
“Eecords.” ^ 
Lower jaws and molars . — Having thus sketched the history of the known molars 
of 3Lastodon pandionis, I proceed to describe some lower jaws and molars of a tri- 
lophodont 3iastodon collected by Mr. Theobald in the Siwaliks of the Punjab, and 
which I have referred to that species from the general resemblance of these molars 
to Ealconer’s original specimens. 
' Eec. Geol. Surv, ludia, Vol. XII, p. 43. 
