30 INDIAN TERTIARY AND POST-TERTIARY YERTEBRATA. 
It. sivalensis. These grounds were, firstly, that the tooth agreed, as far as could he 
judged from the different state of wear of the specimens, with the corresponding 
tooth of a skull of R. sivalensis in the Indian Museum ; and secondly, with the 
corresponding tooth of the left side of a skull of the same species drawn in figure 5 
of plate LXXIY of the “ Eauna Antiqua Sivalensis,” which, though unfortunately 
figured on a small scale, is a very perfect specimen. 
In plate Y, figures 1 and 2 of this volume, two specimens of the penultimate 
upper true molar of this species have been figured in order to illustrate more fully 
this tooth in different stages of wear, and also to indicate the distribution of the 
species. The first specimen (figure 1) was obtained by Mr. Theobald from the 
Siwaliks of the Punjab, and the second by Mr. Eedden from the lower Manchhars 
of Sind. It will be unnecessary on this occasion to describe these teeth in detail, 
as this has already been done when treating of the specimen figured in the first 
volume, above referred to. A comparison of the figures will show that the three 
specimens present the same general characteristics in spite of some minor individual 
peculiarities, and the different conditions of their wear. In the latter respect, the 
Sind specimen is the least worn, the specimen represented in plate Y, figure 5 of the 
first volume rather more worn, and the specimen in plate Y, figure 1 of this volume 
the most so. The latter specimen appears to agree with the original specimen in all 
characters except the relative development of the c crochet,’ which is very much 
smaller : I cannot, however, think that this can be reckoned as more than an in- 
dividual variation. The Sind specimen had originally a well-developed ‘crochet,’ 
but this has been broken away, and the point of attachment is difficult to show well 
in a figure. 
This specimen, however, differs from either of the others in having a vertical 
groove on the posterior aspect of the ‘ anterior collis ’ corresponding to a similar 
groove on the anterior aspect of the same part occurring in all the specimens. Exter- 
nally to this groove there is a slight swelling of the ‘ collis ’ jutting forth into the 
‘median valley.’ The ‘ posterior valley ’ of the Sind specimen differs slightly from 
that of the specimen figured in the first volume. In the latter this valley forms an 
almost completely circular pit; while in the former its antero-posterior diameter 
is longer than its transverse : in this respect the specimen drawn in plate Y, figure 1 
of this volume is intermediate between the other two. A very slight trace of a 
tubercle can be detected at the entrance to the ‘ median valley ’ in the Sind specimen. 
I cannot consider that these slight variations, in the absence of any other more decisive 
evidence, can be considered as anything more than individual peculiarities. The 
variations in the Sind specimen are of considerable importance in identifying other 
specimens with the present species, as will be seen in the sequel. 
Resemblance to R. javanicus. — In the previous volume, it has been mentioned 
that the upper molars of R. sivalensis resemble those of R. javanicus and R. suma- 
trensis. Certain points of alleged difference there pointed out seem, however, to be 
based on individual peculiarities, and are not of general applicability. The re- 
