FAUNA OF THE KARNUL OAVES. 
41 
figs. 4, 4a. This specimen comprises the greater portion of the horizontal ramus 
and the hinder part of the symphysis ; the last five cheek-teeth are in situ , and from 
their worn condition indicate that their owner was an adult individual ; the alveolus 
of pm. 2 still remains, but as there is no trace of that of pm. I the latter tooth must 
have totally disappeared. In size the specimen corresponds with the mandible of 
R. sondaicus. In the broken extremity of the symphysis there is no trace of alveoli 
for canines, and this circumstance, together with the backward extension of the 
symphysis to the anterior border of pmV3 (fig. 4), the convexity of the inferior 
border of the ramus, the sudden inward curvature of the external border of the 
ramus in advance of the same tooth, the backward position of the mentary foramen 
(for.), and the narrow, deep, symphysial channel, indicate that the specimen belongs 
to that group 1 of rhinoceroses in which the canines are usually absent, 2 and all the 
known forms are bicorn. The length of the space occupied by the five cheek-teeth 
is 7*6 inches, and the length of m. 3 1*9 inches. The cheek-teeth are remarkable for 
the extremely thick coat of cement which invests the bases of their crowns ; they 
have no trace of any external cingulum, but do not present any other well-marked 
specific characters. The fragment of a right mandibular ramus (No. F. 238) con- 
taining the slightly worn ul 3 is of rather larger size, the length of the tooth being 
2*0 inches. 
Upper true molars. — Of the upper true molars the crowns 3 of the associated left 
m.2 and m.3 are represented in pi. X. figs. 1, la, ib ; the collection also contains the 
crown of the right m.3 of the same individual, and a less perfect specimen of the 
right m. 1 or m.2 (No. F. 234). The figured specimens are in a middle condition of 
wear, and belong to the more common type of structure, as exemplified in R. 
sondaicus. The first and second costae (c, d) are prominent and form a well-marked 
buttress, 4 and the external surface is deeply curved ; there is a distinct cingulum on 
the anterior and inner surfaces of the anterior collis (a), which is totally absent on 
the posterior collis ( b ) ; the two colies are separated by a considerable interval : the 
crochet ( e ) is well developed and has a separate accessory tubercle in the median 
valley, which occurs in all the specimens in the collection ; there is no combing-plate, 
no antecrochet, nor any trace of a tubercle at the entrance of the median valley ( g ), 
and when more worn the crowns would present only two fossettes. Compared with 
the molars of B. sondaicus the crowns appear to have been relatively rather shorter, 
and may be described as being probably of a sub-brachydont type. 5 The length of 
the outer surface of m-2 is 1*8, and that of its anterior surface 2*1 inches. 
l The Atelodine group (to which R. deecanensis belongs) ; see “ Cat. Foss. Mamm. Brit. Mus.’ pt. III. p. 92. 
a In R. persia, Pohlig (‘ Quart. Joum. Geol. Soc.’ vol. XLII. p. 178), of Maragha lower canines are present. 
3 The roots of all these teeth have been gnawed off by porcupines. 
4 The absence of a buttress is seen in the third right upper true molar of R. unicornis represented in figs. 3, 3a of the 
same plate. 
5 In the preliminary notice these teeth were described as decidedly brachydont. Subsequent examination has, however, 
shown that owing to their partially worn condition and the fact of the base of the crowns having been gnawed away, it is 
very difficult to come to a certain conclusion on this point. 
