PART 2.] 
MedUcoit: Sub-Himalayan Series in Jamil. 
49 
The unworn ridges on the last molar are remarkably clear and sharp, displaying in 
great perfection the cusps on their summits; as in the typical specimen, they have the usual 
transverse bowed form, with clean transverse valleys, without any trace of a median, fore- 
and-aft cleft; the outer side of the worn ridges is lower than the inner side. 
The first ridge of the ultimate molar is unusually thick and massive; it has an 
imperfectly-divided talon on its anterior side: its longer or transverse diameter is 4 
inches, and the shorter or autero-posterior diameter 2 inches; the interval between 
the summits of the second and third ridges is T2 inches, and that between the 
seventh and eighth ridges 1'6 inches. The depth of the valley between the sixth and 
seventh ridges is 1'5 inches; transverse diameter of the fifth ridge is 4'2 inches. 
On the fifth ridge there are no less than thirteen sharply-pointed cusps visible: the sixth 
cusp, counting from the inner side, on this, and the immediately adjacent ridges is some¬ 
what larger than the rest, and its hollow on the outer side somewhat deeper. This sixth 
cusp and valley will probably indicate the lino homologous with the medial fissure of the 
molars of Mastodon. 
The great number of cusps on the ridges of the last molar is an unusual character 
among the Siwalik Stegodons ; a character to which, however, as stated above, I do not 
attach much value: the thirteen cusps on the fifth ridge do not probably represent the total 
number, as the whole of the ridge is not protruded from its alveolus ; there are, no doubt, 
at least two still concealed ; this would bring up the whole number to fifteen. 
The greatest number of cusps contained in a single ridge of any of the molars of 
Stegodon ganesa figured in the “Fauna Antiqua Sivalensis ” is eight; in S. insignis ten ; 
and in S. bombifrons nine. In Stegodon orientalis, Prof. Owen says, the cusps are “about 
a dozen in number”; and in S. sinensis he infers them to be twelve or thirteen, If the 
number of cusps be any criterion of specific identity, as Prof. Owen thinks it is, the pre¬ 
sent cranium would belong to a fifth Siwalik species, which would be most nearly related 
to the Chinese species. The close resemblance of the cranium, however, to the typical 
Stegodon ganesa at once forbids this supposition; and I should be therefore inclined to 
doubt the validity of Prof. Owen’s new species, founded mainly on this character. 
As an instance of the variability of this character, I may cite a specimen of a right 
mandible of S. insignis in the collection of the Imperial Museum (No. 63 S.); the specimen 
contains the third milk-molar just protruded from its alveolus ; this tooth shows seven 
ridges; the fifth of these carries eleven cusps, a greater number than I have seen on even 
a last molar of this species. 1 think, therefore, that this character, as of specific value, 
must be abandoned; if so, Prof. Owen’s Chinese specimens must also be abandoned, as they 
are founded chiefly on this character and some slight variation in the enamel. 
Note upon the Sub-Himalayan Sebies in the Jamu (Jummoo) Hills, by II. B. 
Medlicott, m. a., Geological Survey of India. 
The ‘Jamu Hills’ may conveniently be taken to designate the several ranges, of steadily 
decreasing elevation, between the flanks of the Pir Panjal and the plains of the Panjab, 
from the Ravi to the Jhelam. At the E;ivi they are the direct continuation of the ranges 
in the Kangra district. For many years this ground has been a missing link in our study 
of the great Sub-IIimalayan series of tertiary rocks. So long as those territories could 
boast of a geologist of their own, we refrained from trespassing upon his rights; but soon 
after the departure of Mr. Drew, steps were taken towards closing this gap in our wor . 
Every facility has been granted to us by His Highness the Maharajah and his ministers. 
