24 BULLETIN 171, UNITED STATES NATIONAL MUSEUM 



including most of the teeth on both sides. The remainder consists of 

 maxillary fragments with teeth. About 35 individuals are indicated 

 by lower jaws. Six specimens include both rami and most of the 

 teeth. A large portion of the separate jaws are well preserved and 

 have nearly all the teeth. In two cases jaws and skull were associated. 



A composite skeleton (see pi. 8) has been mounted from the better- 

 preserved remains and placed oji exhibition at the National Museum. 

 This mount is composed of parts belonging to at least six individuals, 

 but a small portion of the skeleton was necessarily restored. The 

 scapulae, left ulna, fibulae, ribs, sternum, and some of the vertebrae 

 were not represented in the collection. The composite skeleton has 

 received the catalog number 10304, and is composed of the following 

 catalog portions: Skull, no. 8188; mandible, no. 10302; three posterior 

 dorsal and three anterior lumbar vertebrae, no. 10303; left radius, 

 no. 8126; parts of both hind limbs and right hind foot, no. 8179; 

 and complete left hind foot, no. 10301. 



Ursus (Euarctos) vitabilis was described by Gidley (1913b, pp. 98-97) 

 from a nearly complete pair of lower jaws (fig. 11a and b), U.S.N.M. 

 no. 7GG5. The description is as follows: 



About the size of U. (Euarctos) americanus, but differs from that species in (1) 

 comparatively larger canines; (2) wider space between the anterior cheek-teeth, 

 combined with a less wide branching of the horizontal rami in general; (3) a 

 relatively larger symphysis, which is more sharply constricted and more flattened 

 latterly behind the canines; and (4) longer diastema between canines and cheek- 

 teeth. 



Most of the ursid material \\\ the collection was obtained since the 

 above description was published. A restud}^ of the group with this 

 added material at hand has brought to light new characters and has 

 furnished further information on the constancy or variability of 

 others. In view of these conclusions it has seemed advisable to 

 redescribe the species on the basis of characters shown by the type, 

 U.S.N.M. no. 76G5, supplemented by a series of skull portions and 

 lower jaws. 



Specific characters. — Size equaling that of the living black bear, 

 Euarctos americanus (Pallas). Upper and lower cheek teeth relatively 

 narrow. P* large and well developed, with prominent protocone. 

 M^ large and usually does not narrow so abruptly posterior to the 

 metacone as does the corresponding tooth of E. americanus. Anterior 

 lower premolars more commonly present and better developed than 

 in E. americanus. P4 well developed. 



All the Euarctos material in the collection is referred to E. vitabilis, 

 which indicates considerable variation in size for this species. Several 

 jaws in the collection compare favorably with those of small individuals 

 of E. americanus or with the glacial bear, E. emmonsii. The largest 

 specimen of E. vitabilis, a skull, U.S.N.M. no. 12247, equals in size 

 large specimens of E. luieolus from Louisiana. 



