URSIDA: 



561 



short. Bony palate not extending behind the last molar tooth. 

 No alisphenoid canal. Feet bear -like, but soles more hairy, and 

 perhaps less completely plantigrade. Fur long and thick. Tail 

 very short. One extremely rare species, A. melanoleucus (Fig. 

 256), discovered by Pere David in 1869, in the most inaccessible 

 mountains of Moupin in Eastern Tibet. Said to feed principally 

 on roots, bamboos, and other vegetables. It is of the size of 

 a small Brown Bear, of a white colour, with ears, spots round 

 the eyes, shoulders and limbs black. In the large size and 

 complex crowns of the upper premolars this genus differs very 

 markedly from the true Bears. The fourth upper premolar (car- 

 nassial) makes no approach to the markedly sectorial type presented 

 by the corresponding tooth of Hycenarctus, its structure being, on 

 the whole, more like that of dElurus. 



Extinct Genera. The genus Arctotherium includes some very 

 large Bear -like animals from the Pleistocene of South America 

 and California, in which 

 the dentition departs 

 less widely from a nor- 

 mal carnivorous type 

 than in the true Bears. 

 Thus the upper car- 

 nassial (Fig. 257) is 

 relatively larger than 

 in Ursus ; while the 

 crowns of the upper 

 molars are broader and 

 shorter. The humerus 

 is said to have an 

 entepicondylar fora- 

 men. Hycenarctus, of 

 the Miocene and Plio- 

 cene of Europe and 

 Southern Asia, has the 

 crowns of the upper 

 molars either square or 

 triangular ; the upper 

 carnassial having three 

 distinct lobes to the 

 blade, while the lower 

 carnassial is practically indistinguishable from that of the Dog-like 

 Dinocyon (p. 556). The proximal extremity of the ulna differs 

 from that of Ursus in having a long olecranon, and thereby re- 

 sembles the corresponding bone of the Dogs. Indeed all the 

 characters at present available tend to show a complete passage 

 from the Tertiary Dog-like animals, through Dinocyon, Hycenarctus, 



36 



Fio. 257. Palate of Arctotherium bonariense, Pleistocene, 

 South America J natural size. (From the Palceontologia 

 Indica.) 



