External Characters of the Hon.*. i'>77 



F./'f/rrfns, Ardiconus, Helarctos, and Tremarclos should rank 

 as species or subspecies is a matter about which there will 

 probably be no unauimitj for many years to come*. 



In my previous paper upon the bears, only the rhinarium 

 and Beet wen- discussed. In the present instance I have 

 added a few notes on the cars. 



The Ears. 



1 have not examined the cats in Thalarctos, Arcticonns, 

 Melursus, and Tremarctos, but, judging from their size in 

 these genera, it may be assumed provisionally that they 

 resemble the ears of Ursus, Danis, and EuarCtos. Taking 



the ears of these three forms as typical, it may be said that 

 in all bears, except Helarctos, the ears arc expanded and 

 flattened distally, with convex margin, and tubular proximally, 

 the angular junction of the tragal and an tit ra gal edges 

 reaching nearly as high as the Low-sel supratragus, and the 

 external meatus lying deep at the bottom of the tube. 

 Thi re is no trace of the bursa, an invariable feature in the 

 Canidae and Pelidse. 



The supratragus (plica principalis) is a strong ridge 

 overlapped anteriorly by the antero-internal ridge and 

 provided towards its posterior end with a conspicuous knob- 

 like thickening. The tragus and antitragus arc small 

 elevations separated by a shallow, narrow notch. The 

 antero-external ridge above the tragus is weak but the 

 antero-internal is strong and prominent where it overlaps 

 the supratragus. The two posterior ridges are likewise 

 moderately strong, the greater part of the external lying 

 deep in the tubular hollow below the point of junction of 

 the two rims externally 1". 



The ear of Helarctos malayanus (fig. 1, (') is much shorter 

 and narrower and simpler than in the three above-men tiontd 

 species. The upper portion of the pinna is considerably 

 less expanded and less rigid and its height from the supra- 

 tragus to the summit is less than its total width, despite its 

 narrowness. All the ridges are soft, not rigid, the tragus, 

 the antitragus, and the anterior and posterior lidges are 



* In 1896 Merriam (Proc. Biol. Sue. Wash. x. pp. 65-83) admitted 

 Euarctos, comprising three species, a.- a subgenus <>t' Ursus. The i 

 tin' North American bears, excluding Thalarctos, 1m- referred to L'rsus, 

 setmt strieto, recognising- two species of the grizzly bear type and three 

 of the brown bear type. 



t The ears of Meatrsus ursinvs and of Helarctos malayanus have been 

 described by Boas (Die Ohrknorpel, etc., p. 1 3* ! , 1912); but the figure 

 of the ear of M. ursinufi is not helpful from my present standpoint. 



Ann. lD Mag. N. Hist. Ser. 9. \'ul.'\. 25 



