273—92 
SIWALIK AND NARBADA PROBOSCIDIA. 
Conclusion. — Prom the above descriptions the ridge-formula of this species 
may be tabulated as follows : — 
2 + 5 + 7 (7—8) + (7 — 8) + (10 — 11) 
2 + 5 + 7 7 + (7 — 12) + (11 — la) 
The ridge-formula of this species is constants as far as we at present know, in 
the milk-molar series, but is liable to very considerable variations in the true molar 
series. In the succeeding sub-genera {Loxodon, Eueleplias) , it will be found that 
this variability extends back into the milk-molar series, which seems to be the most 
constant in its ridge-formula. In Stegodon insignis the number of cusps on the 
ridges seems to be greatest in the milk-molar series, sometimes attaining as many 
as seventeen, while in the second true molar, according to Dr. Palconer, ten seems 
to be the average number. 
Cranium. — The adult cranium of this species is remarkable for the peculiar 
flattened form of the vertex, from which character it derives its specific name ; a 
further discussion on the skull will be found under the head of the next species. 
Dr. Palconer mentions as a character of this species the great height of the ptery- 
goids, which form a ridge running up to the base of the orbits. The lower jaw is 
much like that of the Indian elephant in general shape ; the rami, however, diverg- 
ing to a greater extent posteriorly. 
Distribution. — Remains of this species has been obtained from the Siwaliks, 
and not improbably from the Narbada gravels. 
Species d : Stegodon ganesa, Palconer & Cautley. 
Mistory.' — 'This fourth species of Siwalik Stegodon appears to have been mainly 
founded on an imperfect cranium with long tusks, presented by the late Colonel 
Baker to the British Museum. This cranium is represented on Plates XXI and 
XXII of the “ Pauna Antiqua Sivalensis,” and in a restored state on Plate XXIII 
of the same work. 
Distinctness of the species. — Subsequently to the publication of the Pauna 
Antiqua Sivalensis,” Dr. Palconer^ seems to have had considerable doubts as to the 
specific distinctness of this cranium, and to have thought that it might be merely 
a variety of Stegodon insignis. This conclusion appears to have been arrived at 
because no distinction could be found between the molars of Stegodon insignis and 
S. ganesa, and also because there appears to be somewhat of a transition from the 
typical form of the cranium of S. insignis (P. A, S., Plate XV) towards that of 
.S', ganesa. The typical cranium of the former species is characterized by the extra- 
ordinary depression of its fronto-parietal region, and by the very small width of the 
temporal fossae. S. ganesa, on the other hand, is characterized by a development of 
Pal. Mem., Vol. II, p. 84. 
