1894.] NATURAL SCIENCES OF PHILADELPHIA. 121 



nasals in both are short and rather broad. A most striking feature 

 is the great breadth of the zygomatic arch, anteriorly, which charac- 

 ter, more than any other, gives to the living animal its peculiar 

 physiognomy. In 3, 308 the width at the glenoid fossae is 203 ; at the 

 hinder end of the palate it is but 5 mm. less and and at the plane of 

 the hinder edge of the second molar it is still 180. The broken con- 

 dition of the Ozark skull prevents the corresponding measurements 

 from being given, but enough remains to show their essential agree- 

 ment. In keeping with this character is the increased width of the 

 palate posteriorly, which measures 45 at plane of anterior edge of 

 fourth premolar and 52 at rear end of hinder molar. 



The base of skull is somewhat concave ; a line from the inferior 

 edge of foramen magnum to the proximal border of the alveolus in 

 3,308 falls 16 mm. below the hinder end of the palate. 



The lower jaw is massive and heavy; the angular process strong 

 and curved upward; the fossa for attachment of the masseter is ex- 

 traordinarily deep and rough. 



Dental characters: — The teeth in both skulls are much worn. 

 The hinder molar in the upper jaw is relatively of great size; in the 

 Academy's skull being .118 of the basilar length. The complete 

 series measures : m^ _-— , m'- /#^ii m^ ^^^ "-^ pm'* }%^^^ . In the 



HlxH 22..:)Xl.) 20x10 -t^ 11.0X6 



Ozark skull the lower jaw is missing and the only teeth remaining 

 are the upper right molars; these measure: m- ^11^, m^ 'il^^ p m'* 

 11^. The crowns of the teeth have been worn almost away and it 

 is clear that the hinder molar, especially, measures less than at an 

 earlier period. The second upper molar is broad and rounded be- 

 hind, the width being carried pretty well back to the posterior end; 

 in the Ozark specimen the outer side is someAvhat sloped off behind 

 as in horribilis, although it may be doubtful if this condition was 

 marked in the unworn tooth; there are three inner and two outer 

 cusps. The first molar is short and broad, with four cusps. The 

 fourth premolar is rather short and narrowed in front, the shelf-like 

 projection of the cingulum on the forward inner corner being less 

 than in the grizzly. 



The lower teeth are much worn; the fourth premolar had one 

 cusp, from which there are remains of two longitudinal ridges to the 

 hinder end ; it is not easy to say whether the small tubercle on the 

 inner base of the cusp was also present, but there is some indication 

 that it was. 

 9 



