On some GorgOnopsian Skulls. 507 



is again vaulted, more broadly than and as deeply as the median 

 excavation. The pterygoids do not reach forward to the internarial 

 bar, although they have a slight anterior prolongation on the roof 

 of the median vault. I am again unable to distinguish a median 

 vomer on the palate. It is true that no median suture is to be 

 seen; but the structure of the median plate, as revealed in an obli- 

 que section, seems to preclude the possibility of the median vomer 

 appearing on the palate. The pterygoids seem to be fused. The 

 pterygoid flanges are far forward. The palatines are large bones. 



As Watson has pointed out, the dorsal surface of the skull is very 

 like that of Rhopalodon. The snout is shorter, but the orbits occupy 

 the same caudal position. The frontal forms part of the orbital 

 border. There is a strong rounded ridge running forward from the 

 supraorbital border, giving the prefrontal portion of the snout a 

 squarish form. The front of the snout is rounded in section. 



The "step" in the dentigerous border is weak; but the palatal 

 portion of the premaxilla is considerably higher than the palatal 

 portion of the maxilla, which lias a deep vertical portion forming 

 the outer wall of the internal nares. 



ABCTOGNATHUS WIIAITSI, n. sp. 



The South African Museum possesses a skull collected by the Rev. 

 .1. II. Whaits at lloud Constant, Graafl" Keinet. G. P. (S. A. Mus. 

 Cat. No. 43o7j which is considered to be an 'Arctognathid. The skull 

 is of medium size and is typically a Gorgonopsian in the features of 

 the lower jaw and intertemporal region. The upper surface is weath- 

 ered away, so that the limits of the dorsal bones are not discernable. 

 The dental formula of the upper jaw is probably i 4 c 1 m 4. The front 

 of the snout is weathered away, and only 3 incisors are preserved; 

 but there is sufficient space between the front incisors to permit of 

 the presence in the whole skull of another tooth on each side. In- 

 dental formula, therefore, the skull agrees with that of the genus to 

 which it is here assigned. The upper canine on the right side is a 

 replacing tooth, the previous tooth being in a process of absorption. 

 The molars are very small. All the teeth are finely serrated on the 

 posterior border. 



The chief measurements of the type are as follows: 



Greatest length . circa 170 mm. 



- 



Greatest width . 90 



' 



Length from snout to front ot orbit . ,, 97 



