DAKOTA AND NEBRASKA. 57 



The fron to-parietal outline pursues a course somewhat like the letter W. The 

 squamosal suture pursues a nearly uniform arching course from the acute border of 

 the inion to its descent in conjunction with the alisphenoid. 



The angular processes of the frontals are very short, and the notch between them 

 comparatively shallow and rounded at bottom. The fronto-maxillary suture descends 

 upon the side of the face almost transversely to the orbital margin. 



The nasals posteriorly are spatulate and rounded at the extremities. From the 

 latter position they are of nearly uniform breadth for about a third of their length, 

 when they gradually widen to their anterior extremity, where they are notched in a 

 semi-lunar manner. 



The premaxillaries are more oblique than in the Panther, and their alveolar 

 portion is not impressed for the accommodation of an inferior canine tooth. 



Inferior maxilla. — The lower jaw of Drepanodon primcemis has the same general 

 form as that of the true cats, but exhibits certain important peculiarities. 



The condyle occupies a relatively lower position than in the Panther. The coro- 

 noid process is proportionately much shorter, and instead of curving backward, as in 

 the latter, holds an almost vertical position. The angle is proportionately shorter, 

 thicker, and directed more downward and less inward. 



The fossa below the coronoid process is more restricted to the ramus, independent 

 of the former, than in the true cats. 



The side of the lower jaw below the molar teeth is proportionately deeper, and is 

 more vertical than in the latter. The fore part of the jaw increases in vertical depth, 

 and is further prolonged in the same direction, in a remarkable manner, by means of 

 an angular process, which serves to guard the point of the upper canine tooth when 

 the mouth is closed. The margin of the jaw at the side of the chin is further everted 

 into an acute, prominent ridge, which protects the sharp front edge of the upper 

 canine tooth. 



The chin is more vertical than in Felis. It is oblong-square, with the lateral 

 inferior angles prolonged downward. It is nearly a plane, but is rendered slightly 

 concave at the sides from the prominence of the lateral borders. 



Several mental foramina exist as in Fells, both at the sides and front of the chin. 



Dentition. — The formula of dentition o? Drepanodon i)rima;vus is the same as in the 

 species of Felis, as follows : 



3—3 1 — 1 2—2 1—1 1—1 



In. — ; c. — ; p. ra. — ; sect. m. — ; tub. m. — = 30. 



3—3 1—1 2—2 1 — 1 0-0 



The molar teeth of D. primcevus hold the same relative position with one another 

 and with the other teeth as in ordinary species of Felis, except that the tubercular 



8 



