External Characters of the Bears. 383 



the hind foot the sole, as in Arcticonus thibetanus, but not in 

 Euarctos, shows no deep inrunning depression on the 

 hallucal side and the hairy area of the heel is comparatively 

 short as in Arcticonus. 



The genera above enumerated may be defined by the 

 following combination of external characters : — 



Genus Melursus, Meyer. 



Ehinarium transversely elongate, without median groove, 

 and not traceable to edge of upper lip, which is smooth 

 beneath the rhinarium, the margin of the latter overlapping 

 the valvular nostrils above and laterally. Lips and tongue 

 long and highly protrusible. Ears large. Feet with fused 

 digital pads and area between these pads and the plantar pad 

 hairless ; carpal area of fore feet naked, bat with radial 

 pad forming a rounded eminence as in Ursus, and uluar pad 

 also defined, though indistinctly ; groove on plantar pad of 

 hind foot deep and moderately long. 



Type and only species, M. ur sinus. 



Genus Helarctos, Horsfield. 



Rhinarium not transversely elongated, with median groove 

 traceable to lower edge of upper lip, which is smooth 

 beneath the rhinarium, the latter laterally overlapping the 

 septum between the expanded portion of the nostrils. Lips 

 and tongue less protrusible than in Melursus, more so than 

 in the succeeding genera (? Tremarctos). Ears very small, 

 with supporting ridges, apart from the supratragus, obsolete. 

 Feet with free digital pads and area between them and the 

 plantar pad with four interdigital mats of short hair ; 

 carpal area covered by a continuous large pad separated 

 from the plantar pad by a comparatively narrow crease ; 

 groove on plantar pad of hind foot short and shallow. 



Type, H. malayanus. Number of species or subspecies 

 doubtful. 



Genus Arcticonus, Pocock. 



Rhinarium at least differing from that of Helarctos in that 

 the lateral lobes do not overlap the expanded portion of the 

 nostrils, which are thus exposed in profile view. Upper lip 

 less protrusible and hairy beneath the rhinarium up to the 

 median vertical groove. Ears large, expanded, with well- 

 defined ridges. Feet of the same type as in Helarctos, but 

 with the groove between the plantar and carpal areas better 

 defined and the hairs of the interdigital mats longer. 



Type, A. thibetanus. Number of species and subspecies 

 doubtful. 



