151—10 INDIAN TERTIARY AND POST-TERTIARY YERTEBRATA. 
outer columns, and, according to the excellent woodcut given by Professor Graudry, 
by the greater production of the antero-external ^ngle of the crown. The upper 
molars of A. magnum, to which a reference has likewise been given, are also 
constructed, as mentioned above, on a very similar type to those of the present 
species, but are at once distinguished by their much greater size. The molars of 
A. cuvieri are readily distinguished by the more distinct loop, formed by the 
prominence connecting the external walls of the two outer columns ; — a character 
especially well shown in two molars from Piedmont, in the National Collection at 
South Kensington. The molars of Anthracotherium dahnatinum, 1 if this be indeed 
distinct from some of the other species, have also a more distinct loop between the 
outer columns than in the Indian teeth, and are of slightly larger size than the 
latter. No other species of the genus present any close approximation to the Indian 
teeth. 
It should, however, be observed that the latter present a certain resemblance 
to the molars of Ghoeropotamus parisiensis, but they are distinguished by the greater 
tendency to the development of intermediate tubercles in the latter. 
The enamel of the Indian teeth is marked superficially by a finely reticulate, 
or rugose structure. The dimensions of the specimen represented in figure 10 are as 
follows, viz. : length, 0'68 inch ; width, 0*7 inch ; height of crown, 0‘36 inch. 
Mandible.— In. figures 1 and la of plate XXIV., of this memoir, there is 
represented the hinder portion of the horizontal moiety of the right ramus of the 
mandible of an Anthracotherium , collected by Mr. Theobald, in the Siwaliks of 
the Punjab. The fragment shows the three true molars in an early stage of wear; 
a portion of the associated left ramus of the mandible was also obtained, showing 
the second and third true molars. The specimen is identical in form with the right 
ramus of an Anthracotherium, previously described by the writer under the name of 
A. punjabiense, and subsequently referred to A. silistrense , 2 but as being the more 
perfect of the two has been selected for figuring. The molars present the characters 
of those of typical members of the genus, and do not, therefore, require detailed 
description. The accessory lobe in the last true molar is well developed, and there 
is a distinct tubercle at the entrance of the median valley on the external side of 
each molar. The jaw has its inferior margin strongly convex, and is of considerable 
relative depth, indicating great power of biting in its owner. Below the hinder 
extremity of the last molar, the inferior border of the jaw shows a slight in-cutting, 
probably succeeded in the complete jaw by a descending process, thus recalling the 
corresponding peculiarity of the lower jaws of Hippopotamus and Merycopotamus. 
It should be observed that in the typical forms of Anthracotherium and 
Hijopotamus (such as A. magnum, and E. velaunus), the lower molars of the former are 
distinguished from those of the latter by their less perfect selenodont form ( compare 
i “ Paliiontographica,” Vol, IV. , p. 61, pi. XI. This species is referred by Biittger to Hyopotamus, but, judging from the 
figure, seems to be a true Anthracotherium. 
