SIWALIK AND NADBADA PEOBOSCIDIA. 
31—212 
M. obscurus. — In Mastodon ohscurtis ^ tlie lower molars are relatively much 
narrower than are those of M. falconeri. 
M. pandionis. Some of the molars of Mastodon pandionis are described in 
the succeeding pages, where their distinctness from those of M. falconeri will be 
pointed out. 
Of M. pentelici ^ only the milk-molars appear to be known. The second 
and third upper milk-molars of that species are considerably larger than the cor- 
responding teeth of M. falconeri, and there seems to be a greater number of accessory 
tubercles in the transverse valleys of the former teeth than in the latter. The second 
lower milk-molar in the Athenian species has a relatively larger talon than the 
corresponding Indian tooth ; the two columns of the hinder ridge of the former 
tooth are moreover less closely connected than are those of the latter. Both these 
species seem to have had the common character of being unprovided with pre- 
molars. 
M. productus. — The mandible of M. productus ® is laterally compressed, and has 
a long tusked symphysis, and is, therefore, different from that of M. falconeri. 
The molars are also of simpler structure, and the columns of the ridges wear into 
irregular disks, and not into distinct trefoils of dentine. 
M. pyrenaicus. — I cannot find any description of this species wliich seems to 
be only known from a manuscript note of the late E. Lartet. 
M. tapiroides ^ is sufficiently distinguished from the present species by the 
fact that the transverse ridges of the molars are not distinctly bisected by a 
median longitudinal cleft, as well as by the transverse valleys being entirely unin- 
terrupted by accessory tubercles. The early teeth of the species are figured by 
M. Gaudry® under the name of M. turicensis ; M. Gaudry also seems to include 
M. horsoni under the same specific name, and there does not indeed apj)ear to be any 
difference of specific value between the molars of the two. A fine series of the 
molars of this species are figured in Plates VIII and IX of the above-quoted memoir 
of Lortet and Chantre. 
M. mrgatidens. — Figures of three of the molars of this species are given 
in figures 1, 2, 4 of plate IV of the above quoted memoir of von Meyer. The teeth 
are quite unlike those of M. falconeri, as the ridges and valleys extend without 
interruption across the crown. 
Since none of the Trilophodons with which I am acquainted agree in the 
characters of the teeth with the above described Indian trilophodont teeth, there 
seems to be no doubt as to the specific distinctness of the animal to which the latter 
belonged. 
1 Leidy : “Extinct Vertebrate Fauna of the Western Territories,” pi. 22. 
2 Gaudry: “ Animaux Fossiles et Geologie de I’Attique,” Pis. XTII, XXIII. 
2 Cope; “ Extinct Vertebrata of New Mexico,” United States Geographical Survey, west of 100th naeridian, 
VoL IV, pt.II, P, 306, Pis. LXX— -LXXII. 
Falconer : “ Palaeontological Memoirs” Vol I, p. 103 
® Gaudry : loc. cit. Plate XXIV. 
