SIWALIK RHI NOCEROTHm 
25 
it much too large to have belonged to R. sivalensis, which is the other common Punjab 
species, the large R. platyrhinus being apparently unrepresented there 1 ; and, thirdly 
all the other known species of Acerotherium were provided with large upper and 
lower incisors. The specimen is viewed from the inside, because a great part of the 
outer surface has been broken away, leaving merely a cast of the pulp-cavity. 2 
The tooth had not cut the gum at the time of the death of its owner, and therefore 
exhibits its outline to perfection. The lithograph gives a good idea of its form, 
and as this does not differ in any material point from that of other incisors of 
the family, no description is necessary. The length of the specimen is 4 - 3 inches, 
its thickness l - 5 inches, and the height of the crown 1-9 inches. This tooth in- 
dicates an animal of gigantic dimensions. Another very similar, but much worn 
tooth was also obtained by Mr. Theobald in the same district of the Punjab. It is 
not possible to say whether A. perimense was furnished with a second pair of 
upper incisors. . 
Mandible. — The mandible of a rhinoceros of which two portions are figured on 
plate IV of this volume, is another specimen from Mr. Theobald’s Punjab collection. 
It was obtained from the same district as several of the upper molars of Acero- 
therium perimense, and has been already shortly noticed in the “Records” 3 under 
the name of Rhinoceros planidens. The main reasons for assigning it to the present 
species are, from its association with the upper molars, from its large size, and 
greatly-developed incisors, so characteristic of the genus Acerotherium; and also 
from the presence of a c cingulum 5 on the outer surfaces of the molars, which is like- 
wise, according to Professor Gaudry, a characteristic of that genus. 4 This reference 
is confirmed by the fact that three other forms of mandible of rhinoceros have been 
obtained from the Siwaliks, and have been respectively assigned to the three species 
of true Rhinoceros, in regard to which more will be said in the sequel. 
The specimen under consideration consists of two portions, the larger of which 
(figure 1) comprises the symphysis and a considerable portion of the right ramus 
of the mandible. This fragment shows four molar teeth, the three ’first of which 
are fairly perfect, while the last (ml) has been considerably injured, only its 
central portion now remaining. This tooth being more worn than the three earlier 
teeth must be the first true molar, the other three being the three last of the pre- 
molar series. On either side of the symphysis there is a single huge incisor : the 
one on the right side (in) has only lost its tip ; while that on the left side has been 
broken off level with the alveolus, and is not shown in the figure : the outer side of 
this alveolus exposes the base of this incisor for a length of some five inches, with 
but little diminution in size. The right incisor shows that the protruded portion 
presented a flattened surface superiorly, looking upwards and inwards, w hil e the 
1 ‘ r. G. S. I.,’ Vol. XI, p. 95. 
2 The specimen was lithographed during my absence, and has unfortunately not been drawn in its natural position. 
The left-hand border should have been placed interiorly . 
3 Yol. XT, p. 97. * See “ Les Enchainements du Monde Animal, etc.,” p. 58. 
