4 
INDIAN TERTIARY AND POST-TERTIARY VERTEBRATA. 
true molars of the typical B. pakeindictis (woodcut fig. P) the external surface is still 
flatter than in the jDresent specimens ; the 
buttress being entirely absent and the 
costa?, {c, d) but faintly developed. The 
bases of the two colles (a, h) are, more- 
over, in contact, and there is no tubercle 
at the entrance to the median valley (y) : 
nor is there any ante-crochet. In more 
worn teetlP the median valley becomes 
separated into two isolated fossettes® ; the 
entrance to the valley becoming obliterated, 
instead of having the triangular, imperfectly 
isolated fossette which occupies that place 
in the teeth under consideration (pi. II., 
fig. 2). The tooth regarded as a premolar 
of R. palceindicus (vol. II., pi. VII., fig. 2) 
is quite different from the premolars of 
the specimen represented in pi. II., fig. 4, 
of this volume. 
In the preceding volume'^ a skull of a 
small Siwalik rhinoceros in the British Museum (No. 48,932) was provisionally 
referred to R. palcBindieiis. The inner halves of the molars (whicii are alone 
preserved) differ, however, from those of that species by the separation of the 
bases of the colles, and the partial development of an ante-crochet : has, more- 
over, a distinct cingulum. Now that the specimen represented in vol. II., pi. VI., 
fig. 1, has been shown to be distinct from R. palwindiciis \ it seems pretty certain that 
the above-mentioned skull is likewise distinct. The last premolar of the latter is 
very like the corresponding tooth of the specimens under consideration ; but the true 
molars have not such a marked ante-crochet and constriction of the anterior collis ; 
and it, therefore, seems not improbable that this skull is likewise specifically distinct 
from the specimens under consideration, although the broken condition of its teeth 
does not admit of certain specific determination. Apart from the question, as to the 
sj3ecies of this skull it may be taken as pretty certain that the specimens under 
consideration do not belong to B. palceindicus ; which is also distinguished by its 
greatly superior size. 
Turning to /?. sivalensis, it will be seen from the typical upper molar refigured 
1 This specimen is also figured (|) in volume I., pi. IV., fig. 3, and in the “ F.A.S.,” pi. LXXV., fig. 4, as a premolar : 
it has been shown in vol. II. (p. 44) to he a true molar. The position in which this specimen is figured shows scarcely any 
of the external surface, which is well displayed in the specimens figured in the plates. 
2 “ F.A.S.,” pis. LXXIV., fig. 1 : LXXV., fig. 1. 
3 In the previous volume (p. 44), from the inclusion of other specimens with this species, it was doubted whether this 
was invariably the case. 
4 Page 45. 
d. c. 
a. g. b. 
Fig. 1., Rhinoceros palceindicus, Falc. and Caut. 2nd 
upper true molar, from the Siwaliks : British M useum 
(No. 39,648) : the tooth really belongs to the right 
side, but the figure has been reversed, so as to make it 
correspond with the teeth figured in plate I. i. 
