275—94 
SIWALIK AND NARBADA PROBOSCIDIA. 
Sub- Genus 2 : Loxodon, Dalconer. 
Elephants whose molars in most species have a higher ridge-formula than in the 
Stegodons, and in which the ridges are thinner and higher, and the valleys more 
completely filled with cement. 
Species I : Loxodon planifrons, Ealconer & Cautley. 
General characters. — This species, together with the African elephant, in the 
characters of its molars, forms a link between the higher-ridged Stegodons and the 
extinct European Loxodons, the two species having a lower ridge-formula than any 
other species of the suh-genus Loxodon. We shall find that the number of ridges 
in the molars of this species are liable to a much greater degree of variation than 
is the case in any of the preceding species, — a variability correlated with the greater 
complexity of the molars of this group. Dr. EalconeE makes the ridge-formula of 
this species as follows : — 
3 + 6 + 7 7 + 8 + 10 
3+6 + 7 7+(8-9)+(10— ]1) 
This formula does not give a sufficiently wide range of variation for the number 
of ridges, and another will he proposed after a short survey of the teeth. 
The enamel ridges on the molars of this species are intermediate in height be- 
tween those of Stegodon insignis and those of Euelephas hijsudricus ; when worn the 
crowns present lozenge-shaped cross-sections of the ridges, often with detached cylin- 
ders of enamel near the median line of the tooth ; the enamel is of great relative 
thickness, and much crenulated or crimped in the higher portions of the ridges, 
hut interiorly this crimping is absent ; this causes a great difference in the appear- 
ance of the crown-surface of a little- worn and a much-worn tooth. The molars of 
the species are readily distinguished from those of the Stegodons by the eement 
completely filling up the intervals between the enamel ridges. The present species 
is further distinguished from all other species of elephants, both recent and fossil, 
as far as is at present known, by having been furnished with two pairs of premolars 
in both upper and lower jaws,^ in which respect it agrees with many species of 
Mastodon. 
Crankm. — Eigures of the cranium of L. planifrons will be found on Plates IX 
and X of the “Eauna Antiqua Sivalensis.” The cranium is readily distinguished 
from that of any other species of elephant by the perfectly flat and expanded 
frontal region (whence the specific name), and by the small degree to which the 
temporal fossse extend on to this surface. The nasal aperture is of relatively small 
^ Pal. Mem., Vol. II, p. 9l. 
Fauna Antiqua Sivalensis, PI. VI, figs. 4, 5, 6 ; PI. XII, fig. 8, 
