215—38 INDIAN TERTIARY AND POST-TERTIARY VERTEBRATA. 
these circumstances it is proposed to distinguish the fossil form under the name of 
Ursus theobalcli , in honour of Mr. W. Theobald, late of the Geological Survey, to 
whose untiring labours is due the addition of this (and so many other) species to the 
Siwalik fauna. 
Relation to U. labiatus. — The relationship of Ursus theobaldi to U. labiatus , which 
at the present day stands completely isolated from all other bears, is a matter of 
extreme interest, and one which seems to throw a considerable amount of light on 
the origin of the latter. In the first place the resemblance between the skulls of the 
two forms is so great, and their distinctions from the skulls of other bears are so 
well marked, that there can scarcely be any doubt that the fossil must have been on 
the direct line of ancestry of the living species. Assuming this to be the case, and 
seeing that the cheek-teeth of the former are considerably more developed than 
those of the latter (attaining a development about equivalent to that existing in the 
polar bear), it follows that the aborted dentition of U. labiatus is a character which 
the stirps has acquired comparatively recently, and is not, as might have been 
supposed, a retention of an ancestral feebly developed dentition. The cause of the 
aborted dentition of the aswail ( U. labiatus ) may probably be sought in the nature of 
its food, which, according to the late Dr. Jerdon, 1 consists of the larvte of a gigantic 
longicorfi beetle, of black ants, termiteSj beetles, fruits (particularly the seeds of 
Cassia fistula ^ and the date-palm), honey, and the fleshy flowers of the mohwa tree 
(Bassia latifolia). According to Prof. V. Ball 3 this bear subsists on “the fruits of 
several species of fig, the wild plum, or jujube ( Zizyphus jujuba) , the flowers of the 
mhowa, sugar-cane, &c., it also is fond of termites, or white ants, the larvae of 
several insects and honey.” The larvae and ants are sucked out from their holes, 
after the ground has been opened by the powerful claws of the bears. In contrast 
to this, Dr. Jerdon’s account of the food of the other Indian bears may be cited. 
Of the snow bear ( U. arctos, var. isabellinus ) he observes they feed in autumn ‘ ‘ on 
various fruit, seeds, acorns, hips of rose-bushes, &c., often coming close to villages 
to plunder apples, walnuts; apricots, buck-wheat, &c. Their usual food in spring 
and summer is grass and roots.” The black bear ( U. torquatus [ 'tibetanus ]) is stated 
to live chiefly on “ fruits and roots, apricots, walnuts, apples, currants, &c., also, on 
various grains, barley, Indian corn, buck- wheat, &c.; and in winter chiefly feeds on 
various acorns.” 
It will be seen from these accounts that the food of the aswail contains none of 
the hard substances on which the other bears subsist, and, indeed, consists almost 
entirely of succulent substances which require little or no mastication. The nature 
of its food is, therefore, quite sufficient to account for the aborted molar dentition of 
this remarkable, and, in this respect, highly specialized form. 
1 “ The Mammals of Tndia,” cd. 1874, pp. 72-4. 
2 The fruit of this species consists of long black pods containing numerous seeds buried in a fleshy pulp. 
3 “ Jungle Life in India,” London, 1880, p. 0C0. 
