442 DR. A. GUNTIIER ON JAPANESE MAMMALIA. [JunC 1, 



Islands, an adult Bear, tlie fur of which struck him as particularly 

 light coloured, but of which the skull only has been preserved. It 

 possesses all the dental characteristics of Ursus arctos, by which 

 this species is distinguished from Ursus horribilis. The last upper 

 molar is conspicuously contracted behind, with a distinct convex 

 outer margin ; and the smaller accessory tubercles of all the molars, 

 which are not developed in TJ. horribilis, are in our specimen even 

 more numerous than in tyjiical examples of U. arctos. 



In the series of skulls in the British Museum of Ursus arctos, 

 as well as of U. horribilis, the mastoid process is developed in a very 

 different degree. As regards certain individuals, this is evidently due 

 to age ; but the same difference obtains in individuals which are not 

 merely full-grown, but of apparently the same great age. In some 

 specimens this process is but little raised (3 or 4 Hues) above the 

 level of the bulla ossea; in others the mastoid process projects far 

 beyond the bulla ossea, its extremity being level with the lower 

 margin of the glenoid process, as is also the case in our specimen 

 from Yeterop. 



Although our skull approaches those described by Middendorff 

 and Schrenk as ^ar. beringiana, with regard to the relative length of 

 the two posterior molars, it is of but moderate size, viz. 330 millims. 

 long, and without the knowledge of its origin it could not be dis- 

 tinguished from some of the European varieties. 



Ursus japonicus, Schleg. 



The specific distinctness of this Bear was recognized by Schlegel and 

 Sclater, the latter having figured it in Proc. Zool. Soc. 1862, pi. xxxii. 

 As far as we are permitted to draw an inference from a single skull. 



Fig. 2. 



1. First upper molar of Ursus japonicus. 



2. „ „ Ursus americanus. 



we must confirm their conclusions, arrived at by a comparison of the 

 external characters. Mr. Pryer has sent two skulls ; but one only 

 is that of an adult individual, the second being of a half-grown 

 animal, in which the canine teeth of the permanent set are making 

 their appearance. The skull of the adult is remarkably like that of 

 Z7. ornatus and U. americanus, but smaller than any of the numerous 

 specimens of these two species in the British Museum, scarcely 

 measuring 9 inches from the front margin of the incisors to the 

 occipital condyle. The first upper molar affords a marked distinctive 

 character, being without the broad interior lobe, which is so well 

 developed in U. ornatus and U. americanus. In the younger speci- 

 men, which has its permanent set of molar teeth, the inner lobe is 

 indicated, but much less developed than in the continental species. 



