26 



BULLETIN 171, UXITED STATES XATION.VL INIUSEUM 



surface of the rostrum and most noticeably in the smaller size of 

 the teeth. 



E. vitabilis is also distinct from U. amplidens Leidy (1856) in having 

 lower teeth of much smaller size. 



Upper teeth from the Conard Fissure referred by Brown (1908, 

 pp. 183-184) to Ursus americarivs may represent Euarctos intabilis. 

 The cliaracters of the upper dentition cited by Brown are also seen 

 in the Cumberland Cave bear, as the development of P*, the narrow- 

 ness of M', and the character of the heel of M'. In the past most finds 

 of Pleistocene black bear have been referred to the living species 

 Euarctos or Ursus americanus, and it seems probable that with a very 

 limited amount of material it would be difficult to recognize as dis- 

 tinct a species approaching the living form so closely as does E. 

 vitabilis. 



Table 5. — Measurements (in millimeiers) of skull and superior dentition of three 



species of Euarctos 



Measurement 



Skull 



Length from anterior end of premaxillarles to posterior 



end of condyles 



Distance from line between posterior surfaces of glenoid 



fossae to posterior end of condyles 



Distance between anterior margin of orbit and anterior 



end of premaxillary.. _ - 



Distance from line between postorhital processes of fron- 



tals to inion - - - 



Greatest width across mu/.zle from outer walls of canine 



alveoli - 



Least width between anterior margins of orbits 



Greatest width across postorhital processes 



Greatest width across zygomatic arches 



Width of palate between alveoli of M' 



Superior dentition 



Length of tooth row from anterior margin of C alveolus to 



posterior surface of M^ 



Length of tooth row P* to Ms, inclusive -.- 



C, anteroposterior diameter al alveolus 



C, greatest transverse diameter at alveolus 



P*, anteroposterior diameter 



P<, greatest transverse diameter - -. 



M', anteroposterior diameter 



M', greatest transverse diameter - - 



M>, anteroposterior diameter --- - 



M', greatest transverse diameter — 



F.uaTcfna vitabilis 



U.S.N. 



M. no. 



8181 



284 



91 



105 



170 



'62 

 74 

 102 

 172 

 47 



1 103 

 58 

 120 

 11.6 

 13.2 

 9.4 

 19.3 

 13.2 

 27.7 

 15 2 



U.S.N. 

 M. no. 

 12247 



74.4 

 '83 

 108 



1 45 



1 118 



64 



1 25 



15 



13.8 

 10 

 19.3 

 14.4 

 31.1 

 17.1 



U.S.N. 



M. no. 



8143 



1 110 

 62 

 ' 21.5 

 13 



13.7 

 11.3 

 21 



14.6 

 27.3 

 15.8 



Euarctos 

 americanus 



U.S.N.M. 

 no. 35388 



234 

 96 

 103 

 1C8 



75 

 105 

 180 



50 



103 

 54.2 

 20.6 

 12 



11.5 

 8.2 

 17.2 

 13.2 

 26.6 

 15.7 



Euarctos 

 luieolus 



U.S.N.M. 

 no. 132549 



304 

 101 



108 

 184 



64.8 



71 



101.5 

 186 



47.2 



107 

 59. J 

 20.2 

 12.7 

 12.1 

 9.2 

 19 

 15 

 29 

 17 



.A.ppro.\imate. 



