MARSUPIALIA. 259 



FIG. 152. 



Lower Jaws of American Upper Jurassic Polyprotodont Mammals. (After 

 Marsh.) 



a, canine; b, condyle; c, coronoid process; d, angle; g, mylohyoid groove; 

 s, symphysial surface. 



A. Docodon striatus; right mandibular ramus, inner aspect, twice nat. size. 



B. Dicrocynodon victor; right mandibular ramus, outer aspect, twice nat. size. 



C. Priacodon ferox ; right mandibular ramus, inner aspect, three times nat. size. 



D. Dryolestes priscus; left mandibular ramus, inner aspect, three times nat. 



size. 



E. Dryolestes vorax ; left mandibular ramus, inner aspect, three times nat. 



size. 



F. Asthenodon segnis; symphysial end of left mandibular ramus, outer aspect, 



showing incisors (1 4), three times nat. size. 



G. Laodon venustus; left mandibular ramus, inner aspect, four times nat. size. 



172 



