NIMRAVID^, 975 



occupied by the regularly rounded posterior frontal region. The postorbital 

 angle is exactly half way between the inion and the anterior edge of the 

 premaxillary bone. In the D. felina, according to Leidy's figure, which I 

 find to agree with the specimen which it i-epresents, the last-named distance 

 is equal to the space between the postorbital angle and the postparietal 

 foramen. Thus the region covered by the temporal fossa is shorter in the 

 jD. Cyclops. The front is also convex transversely, excepting where it is inter- 

 rupted by a median longitudinal shallow open groove. The postorbital 

 angles are quite prominent, are subacute, and have a triangular section. 

 They mai-k lateral angles equidistant between the apices of a diamond- 

 shaped space, the posterior angle being the junction of the temporal ridges, 

 and the anterior being theoretically situated between the anterior extremities 

 of the frontomaxillary sutures. The nasal bones are shortened in front; 

 their lateral angles are but little produced, and their anterior borders are 

 concave. The premaxillaries rise high on each side of the nasals, but do 

 not reach the frontals. The face is flat in front of the orbit, and the sur- 

 face is roughened for a space just in front of its border. The zygomatic 

 arches are strongly convex, but somewhat flattened medially, and a little 

 more expanded posteriorly than anteriorly. They are less slender than in 

 Archcelurus deh'dis and Nimravus gomphodus, but their postorbital angle is 

 not larger, being a mere angle. The brain-case is rather large, and is sep- 

 arated from the frontal region by a moderate constriction. The inion does 

 not project so far posteriorly as in some of the cats, and the occiput is higher 

 than wide, and is divided in its superior third by a weak median keel. 



The paroccipital process is small and acuminate; it is directed poste- 

 riorly opposite the superior part of the occipital condyle. An obtuse ridge 

 proceeds downwards and forwards from its base, and terminates in the 

 posterior angle of the posttympanic process. The lateral occipital crest is 

 continued as a delicate ridge into the external angle of the posttympanic 

 process. The latter is well below the paroccipital; it is directed down- 

 wards, ceasing opposite the middle of the posterior face of the zygoma. 

 Its extremity is truncate and triangular, the apex of the triangle being ex- 

 ternal. The suprameatal border is prominent and thin, and the inferior 

 border of the meatus is the deeply set border of the bulla. 



