XX. 
INDIAN TERTIARY AND POST-TERTIARY VERTEBRATA. 
the affinities are discussed on pp. 32 and 151 of the present volume.^ This tooth, 
which is figured in the woodcut fig. 10, agrees precisely with the homologous tooth 
Fig. 10. (?) Mastodon pandionis. The third (penultimate) left lower milk-molar; from Perim Island. 
Viewed from the grinding and outer lateral aspects. British Museum. (No 40779). 
figured in vol. I. pi. XXXIII. fig. 2, and exhibits the vertically grooved enamel 
characteristic of the true molars of M. pandionis. This shows that both in Perim 
Island and the Punjab the true molars of that species are accompanied by trilopho- 
dont milk-molars exhibiting a similar structure of the enamel ; and the primu facie 
presumption therefore is that both types of teeth belong to the same species. If this 
be so the milk-molars figured in vol. I. apparently indicate a variety of M. pandionis 
in which the valleys of the earlier ^ intermediate’ molars are less blocked than usual, 
and thereby approximate to the corresponding teeth of M. pentelici ; with which 
species the penultimate milk-molars agree in their tendency towards a tetralophodont 
type of structure.^ The present specimen agrees very closely with mm. a of the 
last-named species,^ but mm. 3 of the Indian form is relatively shorter and wider. In 
its laterally compressed form the young Punjab mandible described in vol. I. p. 205 
of the present work agrees with the adult mandible of M, pandionis. 
The apparent absence of premolars in the skull to which the specimens figured 
in the first volume belong may perhaps be due either to an individual peculiarity, or 
to their late development. If this identification be correct the specimens figured in 
vol. I. pis. XXXV. fig. 3, and XXXVII. fig. 3, and provisionally regarded respec- 
tively as the upper and lower penultimate milk-molars of M. pandionis are not rightly 
determined. The occurrence of M. pentelici in Persia [vide infra.) is especially 
interesting in view of the affinity to that species presented by M. pandionis [infra, p. 
154) ; an affinity which will be rendered still closer if the milk-molars under 
discussion are rightly referred to that species. 
RANGE OF SIWALIK MAMMALIA. 
General . — Our knowledge of the range of many of the Siwalik Mammalia into 
the regions to the eastward of Burma^ has been considerably increased by recent 
discoveries. 
1 The redetei’mination of the specimens noticed in the preceding' paragraph removes one obstacle to the reference of the 
specimens in question to M. falconeri ; but their intrinsic characters (now that the specimen represented in vol. I. pL XXXII. 
fig. 4 has been shown to belong to M. pandionis) forbid that view. 
2 See Gaudry “ Les Enchainements, etc.— -Mammiferes Tertiaries,” pp. 1§0, 181, fig. 211. (1878). 
3 Gaudry “ Anirnaux Fossiles et Geologie de 1’ Attique," pi. XXII. fig. 3. 4 Vide supra vol. II. pp. 65, 66. 
