384 On some External Characters of the Bears. 



Genus Tremarctos, Gervais. 



External characters known to me only from dried skins, 

 but apparently resembling- those of Arcticonus , although the 

 examination of fresh material will probably reveal some 

 differences in the feet and other organs. Pending this the 

 two genera may be distinguished by the skull-characters I 

 pointed out in 1917. 



Type, T. ornatus. One or two species. 



Genus Euarctos, Gray. 



Rhinarium, lips, and ears apparently essentially as in 

 Arcticonus, but the ears smaller. Feet differing from those 

 of Arcticonus in that the carpal area is thickly covered with 

 hair, from which the ulnar carpal pad arises as a hemi- 

 spherical excrescence towards the inner side of the wrist, 

 and the groove on the plantar pad of the hind foot is much 

 deeper, wider, and longer, and filled with hair spreading 

 inwards from the margin of the sole. 



Type, Eu. americanus. A few species. 



Genus Ursus, Linn. 

 Approximately resembling Euarctos in external characters, 

 except that the digital pads are united by membrane in 

 the basal half of their length, although capable of consider- 

 able separation. Further distinguishable from Euarctos by 

 the cranial features described by Merriam in 1896. 



Type, U. arctos. Probably a few species, certainly many 

 subspecies. 



Genus Danis, Gray. 



In external features agreeing with Ursus, but with the 

 pads of the third and fourth digits of the hind foot completely 

 fused in the basal half and inseparable, and all the rest of 

 the digital pads united by much narrower webbing, so that 

 the digits themselves are susceptible of very slight di- 

 varication. 



Type, D. horribilis. Two species, possibly more. 



Genus Thalarctos, Gray. 



Rhinarium, lips, and ears, so far as it is permissible to 

 guess, resembling those of Ursus and Euarctos, and the feet 

 conforming to the same general type as in those genera*, 

 but the soles much more overgrown with hair enormously 

 reducing the size of the plantar pads, the pad behind the 

 plantar pad of the hind foot represented by a small elon- 

 gated piriform pad towards the inner side of the foot about 

 halfway between the plantar pad and the heel. 



Type, Th. maritimus. Only one species admitted. 

 * In newly-born cubs the digital pads are not united. 



