Preliminary Synopsis of American Bears. 77 



ears are twice as long as the tail. The average basilar length of 

 six skulls from Monterey and old Fort Tejon, California, is 336 

 mm., while the average of two adult males from New Mexico is 

 only 310. The average of four adult male horribilis from the 

 northern Rocky Mountains is 316 mm. But the numbers here 

 averaged are too small to afford reliable results. 



Ursus richardsoni INIayne Reid. Barren Ground Bear. 



PI. IV, flg. 6 ; pi. V, fig. 5 ; pi. VI, fig. 3. 



Urstis ridiardsonii Mayne Reid, Bruin : The Grand Bear Hunt. London, 

 1860. Am. ed., pp. 260-2()l. 18(U. 



Type locality — Great Slave Lake, Arctic America. 



Geographic dislribution. — Harren grounds between Hudson Bay and the 

 Mackenzie River. 



Characters. — Size smallest of the American big bears; skull short; 

 zygomata broadly spreading; temporal ridges conspicuous and turning 

 abruptly inward from postorbital processes (fig. 17); teeth large and 

 broad. Adult skulls of the Barren Ground bear may be known from all 

 other species by the form of the frontal shield, which is truncated pos- 

 teriorly l)y the temporal crests (figs. 10 and 17). The temporal crests, 

 beginning on the posterior edge of the 

 largeh- developed ]iostorbital processes, 

 run toward the median line, forming 



Fig. i6. Fig. i7- 



Barren Ground Be^r [Ursus richardsoni), .showing high sagittal crest and abruptly 



spreading temporal ridges. 



nearly a right angle with the cranial axis, as shown in the accompanying 

 illustrations. The postorbital processes are long and peg-like and flat- 

 tened on top. The sagittal crest is correspondingly elongated, reaching 

 forward beyond the middle of the frontals and measuring more than half 

 as much as the upper surface of the skull. The muzzle is short and 



