DAKOTA AND NEBRASKA. 65 



The occipital region, the mastoid process, and the archway to the auditory 

 meatus between the latter and the root of the zygoma are almost identical in 

 character with the same parts in D. primcevus. 



The infra^orbital foramen is as large as in the latter, and opens above the interval 

 of the last premolar and the sectorial molar. 



The parietals are co-ossified in the course of the well-developed sagittal crest. The 

 fronto-parietal and squamous sutures are too much obscured by accidental fissures in 

 the specimens under observation to judge accurately of their course. The frontals 

 appear to have been co-ossified. 



The nasals together posteriorly form a triangle received into a deep notch of the 

 frontals. From the latter position the}' slightly and gradually widen to their 

 anterior extremities, which end as in D. primcBviis. 



Angular processes of the frontals, extending between the nasals and maxillai'ies in 

 the Panther, and in a less degree in D. primcevus, appear hardly to have existed in 

 Dinictis felina. The fronto-maxillary suture is directed across the side of the face to 

 the supra^orbital margin in a nearly transverse course. 



The lower jaw of Dinictis felina has nearly the form of that oi Drepanodon 

 2)rimcevus. The condyle is not so low down, and the coronoid process is much longer 

 and curved as in the true cats. The form of the chin is like that of D. primcevus, 

 but is smaller. It presents similar prolongations downward to protect the points of 

 the upper canine teeth, but not quite to the same length. The side of the jaw 

 below the molars is less deep than in D. primcEvus. 



As in the Mink and common Weasel, Dinictis presents the following formula of 

 dentition : 



3—3 1—1 2—2 1—1 1—1 



In. ; c. ; p. m. ; sec. m. ; tub. m. =-84. 



3—3 1—1 3—3 1—1 1—1 



The teeth of both jaws of Dinictis hold nearly the same relative position with 

 one another as in Drepanodon and Fells. 



Molars. — The molar teeth, as in Drepanodon primcevus, generally have proportion- 

 ately longer, narrower, sharper and more pointed crowns in relation with their 

 breadth than in the true cats. 



The upper first premolar is a small tooth occupying the same relative position as 

 that of Drepanodon and the cats. As in the former, it has a simple, broad, laterally 

 compressed conical crown, with the apex in advance of the middle ; and it is inserted 

 by a pair of fangs. 



The second upper premolar is larger than the corresponding tooth of Drepanodon 

 primcevus in relation with the succeeding tooth. The crown consists of a single 

 comparatively large, laterally compressed, conical cusp, with a small heel-like sub- 



' 9 



