209—28 
SIWALIK AND NARBADA PROBOSCIDIA. 
form of the cranium. The mandible was sub-circular in section, and had a short 
symphysis. 
In my first notice of the molars of this species in the “ Records,” it was stated 
that cement was present in these teeth ; this I now find to be an error, into which 
I was led by the exfoliation of the enamel in those specimens. 
Specific distinctness. — Our next point is to institute a comparison between the 
molars of Mastodon falconeri and those of other species of the genus, in order 
that we may he assured of its distinctness as a species. In this comparison, we 
may at once dismiss all species belonging to the section Tetralophodon, in which 
the “ intermediate” molars never carry less than four transverse ridges, and wq 
may accordingly confine ourselves to the trilophodont section of the genus. 
Of that section the following list gives the names of all the described species 
(exclusive of the present) with which I am acquainted, > ; — 
1. M. andium (Cuvier) — N. America. 
2. 31. angustidens (Cuvier) — Europe. 
3. M. horsoni (J. Hays) — Europe. 
4. 31. humioldtii (Cuvier) — S. America. 
5. 31. maximus (Cuvier) — America. 
6. M. ohscurus (Leidy) — N. America. ^ 
7. 3/1. pandionis (Falconer) — India. 
8. M. pentelici (Lartet and Gaudry) — Europe. 
9. 31. productus (Cope) — N. America. 
10. M. pgrenaicus (Lartet) — Europe. 
11. M. tapiroides (Cuvier) — Europe. 
(M. turicensis, Schinz). 
12. 31. virgatidens (Meyer) — Europe. 
Commencing with Mastodon angustidens^ we shaU find in the Fauna Antiqua 
Sivalensis,”^ figures of the third upper milk-molar and of the second upper true 
molar. These teeth correspond with the two molars of Jf. falconeri represented in 
figs. 3 and 1 of Plate XXXII of the present memoir. In the following table the 
dimensions of these four teeth are arranged side by side, viz . : — 
Length of third milk-molar 
Width of ditto ditto 
Length of second true molar 
Width of ditto ditto 
M. angustidem. M. faXconeri. 
. 2-8 3-04 
. 1'6 20 
. 4-5 5-2 
. 2-6 3-5 
As far, therefore, as mere size goes, there is a very considerable difference be- 
tween the molars of the two species, which appears to be pretty constant. The 
molars of both species agree in having trefoil-shaped discs of wear on one column 
^ Figures (of the natural size) of the molars of this species are given in Herr Vacek's Memoir on Mastodon. 
“ Abhand der k. k. Geol. Reich Wien., vol. vii,pt. 4, 1877, plates IV, V. 
s Plate XL, figs. 7—9. 
