SIWALIK CAMELOPAKDALIDAk 
35—133 
of which points my own opinion differ considerably from those of previous writers. 
Figures have been given of a few of the molars, of a cervical vertebra, and (on a 
reduced scale) of the ‘ cannon-bones ’ and a phalangeal. 
Upper molars. — In figure 1 of Plate XXI, the left upper true molar of Siva- 
tkerium giganteum figured in the first volume of this work, has been redrawn and 
lithographed in order to facilitate comparison with the molars of Vishnutherium and 
Bydaspitkerium. The tooth is an isolated specimen, collected by Mr. Theobald in 
the Siwaliks of the Kangra district, and from its presenting disks of pressure both 
on the preaxial and postaxial surfaces, must be either the first or second true molar. 
The tooth is not so large as some other specimens, but exhibits well the points 
characteristic of the genus. The most distinguishing point is the great develop- 
ment of the c costse ’ on the external surface, sections of which are exhibited on the 
worn masticating surface shown in the figure. The c lobes ’ are oblique to the long axis 
of the crown in only a small degree. The central enamel pits are extremely deep, and 
the enamel very rugose. A peculiar character is the presence of a projection from 
the preaxial surfaces of both the hinder ‘ lobe’ and ‘ crescent 5 projecting in front of 
the postero-external angles of the anterior ‘ lobe 5 and c crescent.’ These projections 
appear to be constant in all specimens of the upper molars, and are unknown in 
other genera. There is no trace of a ‘ cingulum ’ on the inner aspect of the ' cres- 
cents,’ but there is a minute tubercle placed high up in the ‘ median valley ’ and 
attached to the anterior crescent. 
A very fine specimen of the anterior upper molars of the left side is contained 
in the collection of the Eoyal College of Surgeons, of which we have a cast in the 
Indian Museum (Xo. B. 361). The teeth shown are the third and fourth premolars 
and the last true molar, the latter being rather larger than the specimen figured 
here. The premolars are remarkable for their enormous absolute and relative size. 
The following table gives the dimensions of these teeth, and of the specimen 
figured here, which is arbitrarily taken as a first true molar : — 
Length of 3rd premolar 1'96 
Width „ „ 2-08 
Length 4th „ . 1'6 
Width „ ........ 2-2 
Length 1st true molar . 2‘04 — 2'2 
Width „ . 2-1 —2-2 
Mandible. — The mandible, of which a left ramus is figured in plate XXI, 
figure 1, of the first volume of the “ Palseontological Memoirs,” has been already 
noticed, and its measurements given in describing the lower jaw of Bydaspitkerium 
megacepkalum . The characteristic points of this jaw are its great size, its great 
depth, and the well-marked ‘ costse ’ on the inner surfaces of the molars. In treating 
of the last lower true molar of this jaw, Professor Owen observes 1 that the third lobe 
“ presents in the Megaceros and Sivatherium a deeper central enamel island or 
fold, which also characterises the smaller third lobe in the Giraffe.” 
“ Odontography,” p. 335, and note. 
