8 
INDIAN TERTIARY AND POST-TERTIARY VERTEBRATA. 
Further comparisons . — Having now described all the known dental and mandibular 
remains of the present species ; and its distinctness from the other named Siwalik 
species having been indicated ; it remains to institute a wider range of comparisons. 
Commencing with the non-Siwalik Asiatic species, U. deccanensis^ is distinguished by 
the absence of mandibular cutting teeth, and of an ante-crochet to the upper true 
molars, which are furnished with combing-plates. The upper premolars are, 
however, strikingly like those of the present species, but are distinguished by the 
greater development of the crochet, and the shape of the cingulum ; which forms an 
inverted V, instead of an oblique line on the inner surface of the crown. The 
molars of R. namadicus are unknown. The last upper molar of the doubtfully 
distinct R. sinensis^ has no ante- crochet. 
Of the existing species, the large unicorn Indian rhinoceros is distinguished by 
its complex upper molars ; while those of the Javan and Sumatran species® are of 
the R. sivalensis type. The two African species are distinguished by the absence of 
permanent cutting mandibular teeth ; the same character also obtaining in R. 
pachijgnathus of the Pikermi beds. The four species of the higher pliocene and 
pleistocene of Europe are likewise distinguished by the same -character ; as well as 
by the absence of pm. 1 , which is shown by the specimen represented in plate II., 
fig. 4, to have been present in the Biigti species. It may be added that R. tichorhinus 
is widely distinguished by the complex 
structure of its upper molars^; while in 
R. megarhinus^ (woodcut fig. 3), and R. 
leptorhinus^ Ow., the upper cheek-teeth 
have not such a distinct ante-crochet, such 
a stout cingulum to the premolars, or such 
a distinct tubercle at the entrance to the 
median valley ; the crochet is moreover 
always larger. In R. etruscus^ which 
Prof. Boyd Dawkins considers to be allied 
to the miocene forms, the upper pre- 
molars have a well-developed cingulum, 
and a distinct ante-crochet exists in the 
true molars. This species is, however, 
readily distinguished by the cingulum of 
the premolars being less prominent, and 
running straight across the colles; both of which have the same inward extent. The 
1 Su^ra., vol. I., p. 1, pis. I. — III. 2 Owen, ‘ Quart. Journ. Geol. Soc.,’ vol. XXVI., pi. XXIX., fig. 1. 
3 The so-called S. lasioiis and if. inermis are not distinguishable by dental charaeters from the Sumatran and Javan species. 
4 Owen, “ Brit. Foss. Mamm. and Birds,” fig. 122, p. 329. 
5 Lortet and Chantre, ‘Arch. d. Mus. d’Hist. Nat. d. Lyon,’ vol. II., pi. XVII. 
6 Owen, op. cit., fig. 141, p. 373. 7 The writer is indebted to Prof. Boyd Dawkins for this figure. 
8 Boyd Dawkins, ‘ Quart. Journ, Geol. Soc.,’ vol. XXIV., pi. VII. 
Fig. 3. Rhinoceros megarhinus,^ Christol. Second 
right upper true molar, slightly worn. y. A, 
median valley ; B, anterior colUs ; B, posterior do.; 
F, posterior valley ; H, crochet ; K\, K 2, first and 
second costae. Pleistocene, England. 
