ursus 291 



meatus distinctly tubular, usually longer than wide ; postglenoid 

 process heavy, rising to level of hamulars. Interorbital region 

 broad, the width across robust, triangular, postorbital processes 

 about equal to that of brain-case, the region immediately between 

 orbits always a little concave and sometimes conspicuously so, 

 that at base of each postorbital process usually somewhat swollen. 

 Zygomata moderately expanded, the greatest zygomatic breadth 

 opposite anterior glenoid edge ; orbital process well developed. 

 Rostrum equal to less than half condylobasal length of skull, the 

 width across alveoli of canines equal to or less than depth at 

 front of orbit, the depth at front of nasal equal to about half 

 distance from orbit to front of premaxillary ; nares rather large, 

 their lateral margins slightly everted ; nasal bones elongate wedge- 

 shaped, squarely truncate anteriorly, their posterior extremity on 

 level with or extending slightly behind nasal branch of maxillary ; 

 anteorbital foramen over metacone of m 1 or paracone of m 2 ; 

 palate narrow, its width between posterior molars contained about 

 3£ times in median length ; extension behind molars nearly 

 parallel-sided, its length equal to about three-quarters breadth ; 

 mesopterygoid space 1| times to twice as long as wide, its anterior 

 border squarish or rounded, its lateral borders nearly parallel ; 

 hamulars small but distinct, slightly hooked outward. Man- 

 dible robust, the depth of ramus behind large premolar con- 

 tained about five times in length, the height of posterior portion 

 (measured to level of lower border) a little less than half length j 

 coronoid process broad, its width at level of alveolus slightly 

 greater than height, the anterior border at first straight then 

 evenly convex to overhanging tip, the posterior border concave ; 

 angular process short, extending slightly if at all behind level of 

 articular process, its inner border nearly straight, its outer border 

 convex. 



Teeth. — The teeth are moderately large relatively to size of 

 skull. Upper incisors forming a continuous row, separated at 

 each side from canine by a diastema about as wide as inner 

 incisor ; i 1 and i 2 sub-equal, the former slightly the smaller, the 

 anterior face smoothly rounded, a little more than half as wide 

 as high, the posterior face abruptly concave, with shelf-like 

 posterior extension, the cingulum slightly developed and forming 

 a rudimentary nodule on inner and outer side of i 2 and on outer 

 side of j 1 near level of middle of anterior surface ; i 3 with crown 

 area nearly double that of i 2 , and height nearly half that of 

 canine, its anterior surface smoothly rounded but with pronounced 

 nodule on inner side, its posterior surface gradually concave 

 and without shelf -like extension ; a thickened ridge along its inner 

 border and a low but somewhat trenchant ridge slightly outside 

 of middle. Lower incisors forming continuous row between 

 canines, their crown area increasing regularly from first to third, 

 their height approximately equal ; each has a high inner cusp and 

 a low outer tubercle best developed in i 3 ; posterior border slightly 



