DAKOTA AND NEBRASKA. 55 



The entrance to the auditory meatus is a comparatively narrow archway, instead 

 of a broad one as in the Panther. It is bounded posteriorly by a longer and much 

 more robust mastoid process than in the latter. The process is directed obliquely 

 downward and forward, and is trilateral, with a truncate apex. 



The orbit is proportionately of much less capacity than in the Panther. The 

 orbital entrance likewise is much smaller and more posterior in its position, or is 

 more median in relation with the length of the skull. It is more rotund in form, and 

 more vertical in its direction, or presents less upward and forward. 



The post-orbital process of the frontal bone is about as well developed as in the 

 Panther, but that of the malar bone is comparatively short and blunt. The inter- 

 vening gap is rather greater. 



The malar bone, forming the anterior root of the zygoma, is much less prominent 

 than in the Panther. The infra-orbital foramen is considerably larger, and occupies 

 a more elevated position in relation with the infra-orbital margin. It is situated 

 above the position of the fore fangs of the upper sectorial molar. 



The face in advance of the orbit is longer and shallower, or narrower and more 

 pointed than in the true cats. It is convex, instead of being depressed as in the 

 Panther, between the position of the forehead, the swell of the canine alveolus, and 

 the orbit. 



The premaxillaries project proportionately more in advance of the canines than in 

 the Panther. 



Suj)erior view. — In the upper view of the skull of Drepanodon primcevus, the 

 cranium back of the temporal arches is observed to be proportionately much smaller 

 than in the Panther. It is also less convex at the sides, and more constricted at its 

 fore part. 



The sagittal crest is as prominent, but is shorter than in the Panther. 



The forehead is broader, more arched transversely between the orbits, but is more 

 depressed along the middle. 



The face in advance of the forehead and orbits has a more prolonged demiconoidal 

 form than in the Panther, being proportionately longer and generally narrower. Its 

 upper part, however, is wider, and is transversely convex. 



The bones of the nose are less depressed along their adjacent parts. Posteriorly 

 they are nearly fiat ; anteriorly they terminate together in a more prominent median 

 point, and are not inverted to the same extent as in the Panther. 



The anterior nasal orifice is smaller than in the latter. It has nearly the same 

 form, but is less wide in relation with its height. 



Posterior view. — The occipital region has nearly the same form as in the Panther. 

 It is more prominent in the median line just above the occipital foramen. The 

 mastoids, from their large comparative size, appear very conspicuously as the pro- 



