SIWALIK RHINOOEROTIDiE. 
33 
The specimen, as far as can be judged from the small figure in the “ Eauna 
Antigua Sivalensis,” 1 is distinguished from the corresponding molar of R. palcein- 
dicus by the presence of the large ‘ buttress ’ at the antero-external angle, which is 
wanting in the latter. It is distinguished from the corresponding molar of R. 
platyrhinus by the absence of a ‘ combing-plate.’ 
The specimen figured in the preceding volume shows that when worn down only 
a single ‘ fossette ’ would remain on the crown, and this would he the case with the 
specimen figured here. In the specimen on the opposite side of the skull of which 
one tooth is figured in the first volume, the ‘ crochet 5 extends completely across 
the ‘ median valley,’ so as to cut off an ‘ accessory fossette.’ A detached specimen 
of a last upper true molar in the Indian Museum, from the Punjab, apparently 
belonging to the same species, shows a distinctly double c crochet.’ 
Third upper premolar. — The specimen drawn in plate V„ figure 6, so closely 
resembles the third or penultimate right upper premolar of 11. javanicus, that, 
judging from the similarity of the true molars of the two species, there can be 
little doubt but that it is the corresponding tooth of JR. sivalensis. It was obtained 
from the Siwaliks of the Punjab by Mr. Theobald : it is quite perfect, and about one- 
third worn down. The characteristic features of this tooth are the following. The 
‘posterior valley’ forms a funnel-shaped pit, apparently nearly as deep as the 
‘ median valley : ’ the ‘ anterior collis ’ is considerably larger than the posterior, and 
the ‘ crochet ’ is double or bifurcate : there is no ‘ combing-plate.’ The external, or 
dorsal, surface shows two ‘ costae,’ the posterior of which is slightly, and the anterior 
very strongly, developed ; the antero-external angle is produced into an acute pro- 
cess, and this, together with the anterior ‘ costa,’ shows a tendency to the formation 
of the ‘ buttress ’ so characteristic of the true molars ; the whole ‘ dorsal ’ surface, 
however, remains approximately straight, and not highly curved, as in the true 
molars. There is a faint trace of a ‘ cingulum ’ on the internal surface. The fol- 
lowing dimensions show the relations of this specimen with the corresponding tooth 
of JR. javanicus : — 
H. sivalensis. H. javanicus. 
‘ Length of internal surface ...... 12 1*0 
„ of anterior „ 2‘1 1’8 
„ of external „ l - 6 P5 
„ of posterior „ 17 1'6 
Almost the only difference that can be detected between these two teeth is 
that in the fossil species the double ‘ crochet ’ is thicker and larger than in the 
living. According to Professor Plower 2 the double ‘ crochet ’ of the premolars of R. 
javanicus is a distinctive character of that species ; never occurring in, the other- 
wise very similar, teeth of R. sumatrensis. The occurrence of a similar peculiarity 
in (at all events some of) the premolars of R. sivalensis is another indication of the 
close affinity o p that species with the Javan rhinoceros. It may be added that some 
PI. LXXIV, fig. 2a. 
2 Loc. cit. p. 449. 
