225—44 
SIWALIK AND NARBADA PROBOSCIDIA. 
With regard to the dentition, the molars, in regard to the number of ridges borne 
on their crowns, followed the normal trilophodont rule. The pattern of the molars 
approaches nearest to that of the molars of M. angustidens, hut presents important 
differences which will he pointed out below. If the above identifications are correct, 
t he species was provided with premolars. 
Distinctions and differences. — From Mastodon falconeri (the only other Indian 
species with a trilophodont ridge formula to the molars), the present species is at once 
distinguished by its compressed mandible with its long symphysial rostrum. It is 
further distinguished by the more complex pattern of the crowns of the molars, 
and by the irregularly shaped discs, in place of the perfect trefoils of dentine, pro- 
duced by the detrition of the ridges. The molars of 31. pandionis are further, 
distinguished by the greater absolute height of the transverse ridges, and by the 
greater extent to which the intervening valleys are blocked by tubercles ; there is 
also a greater tendency to an alternate arrangement of the columns of the ridges. 
Cement is present in 31. pandionis and absent in M. falconeri. 
3Iastodon angustidens. — It is imfortunate that in the mandible of M. pandionis 
the jiortion connecting the alveolar part of the ramus with the sym23hysis is wanting, 
so that we are unable to institute a comjDarison between the comjolete mandible of 
31. angustidens ^ and M. pandionis. A very beautiful specimen of the extremity 
of the mandible of M. angustidens, is figured by Dr. Biederman '3 that specimen 
carries two small sub-cylindrical tusks, and is greatly contracted laterally near 
the 2>rox im a,l end of the symphysis, jn’oximately the rostrum has a deep trough, 
which expands into a flattened plate anteriorly. Tliis symphysis is quite different 
in form from that of the tuskless symjfliysis of M. pandionis flgured in figure 1 of 
Plate XXXVI : it approaches nearer to the tusked specimen in figure 2 of the 
same plate. There are, however, very considerable differences in the form of the 
trough and tusks, which are somewhat difficult to point out, but which will be 
very apparent if the two figures are compared together : the tusks in M. pandionis 
are much curved, the concavity looking upwards, and very highly compressed, while 
those of 31. angustidens are quite straight,^ and in the young individual, according to 
Falconer,^ had a pyriform cross section. To the tuskless variety of M. pandionis, 
there is no corresponding form in 31. angustidens, since in that species both sexes 
were alike furnished with inferior tusks ; ® the peculiar trough-hke symphysis of the 
tuskless variety of M. pandionis has, therefore, no representative in 31. angus- 
tidens. The two species resemble one another in the compressed rami and long 
symphysis of the mandible. 
The molars of the Indian seem to be distinguished from those of the European 
species by their somewhat more complex pattern, and by the surfaces of dentine 
^ “ Fauna Antiqua Sivalensis,” PI. XLIV, fig. 5. 
2 Abbandl. der. Schweiz. Pal. Gesell, Vol. Ill, pi. II, fig. 4 — (Biederman’s memoir), 
^ Von. Meyer : “ Palaeontographica,” Vol. XVII, pi. VJII. 
“ Palaeontological Memoirs,” Vol. II, p. 41. 
6 Ihid., p. 13. 
