212 PROCEEDINGS OF THE ACADEMY OF [1889. 



long. In spite, therefore, of the greatly elongated cranium, includ- 

 ing in that term the region behind the anterior rim of the orbit ; the 

 space allotted to the cerebral hemispheres is comparatively short, 

 while the cavities for the hind-brain and the olfactory lobes are 

 long. The face in advance of the orbits is much contracted. 



The upper contour of the cranium slopes sharply downwards and 

 backwards from the highest point of the skull just behind the orbits, 

 while that of the face slopes downwards and forwards from the same 

 point, the two meeting in an open V. Of course at the point of 

 meeting the skull is disproportionately deep, while the muzzle, and 

 especially the occiput, is low. This gives the skull of Dinictis felina 

 a very characteristic physiognomy and is an exaggeration of the 

 arrangement found in Hoplophoneus and others of the Nimravidce, 

 but in the John Day species, I), cyclops, the contour is very different. 



The premaxillaries have well developed alveolar portions, which, 

 however, form a nearly straight transverse line and project but little in 

 advance of the canines ; the ascending ramus is very long and nearly 

 vertical, its upper portion sloping backwards less than in the viver- 

 rines and further removed from the frontals than in that family. 

 The maxilla has a high and short (antero-posteriorly) preorbital por- 

 tion which joins the frontal by a short straight suture. The suborbital 

 part of the maxilla exceeds the preorbital in length more than in the 

 cats and very much more than in Viverra, as the orbit is placed far 

 forward. The frontals are strongly inclined upwards and backwards 

 and appear to be very decidedly shorter than in the cats ; anteriorly 

 they together form a notch to receive the ends of the nasals, but the 

 fronto-nasal process is very short and more obtuse than in the cats, 

 its maxillary and nasal edges forming a right angle. The nasals are 

 longer than in the cats, but otherwise very much like them. The 

 lachrymal is small and does not extend at all upon the face, as it 

 docs in the creodonts, and just within the edge of the orbit it is 

 pierced by two foramina. 



The parietals, so far as the great Assuring of the specimens will 

 allow of a determination, seem to be much longer than in the cats 

 and to exclude the frontals from all share in roofing the cerebral 

 hemispheres. At all events the very long sagittal crest runs to a 

 point in advance of the post-orbital constriction, from which point 

 the supraciliary ridges diverge rapidly and pass outwards in bold 

 curves to the short post-orbital processes of the frontals. Besides 

 being long the parietals are deep vertically, extending far down on 

 the sides of the cranium. 



