SKULL OF A PARIASAURIAN REPTILE. WH 
groove running round the bone, which particularly impresses the 
lower surface. In section a disturbance of the cancellar tissue 
suggests the point of separation of the basisphenoid. ‘The upper 
surface of the basioccipital supports the very massive exoccipital, 
in front of which its upper surface is excavated on each side of 
the middle line by a deep pit, continued outwards by a groove 
which forms the lower half of the enormous foramen jugulare. 
The lower part of the basioccipital is almost entirely concealed 
by the overlapping basisphenoid, but it is produced in low yet 
massive tubera basisphenoidales. 
Text-figure 1. 
The cranium of “ Pariasaurus,” the Hottentots Rivier specimen, viewed 
from the side.(X 4%). 
Boc., Basioccipital ; B.Sp., Basisphenoid; Car., Canal for internal carotid artery; 
Fen.Ov., Fenestra ovalis ; Parv.Sp., Parasphenoid; Pin., Pineal foramen ; 
Pit.Foss., Pituitary fossa; Sph.Hth., Sphenethmoid. The figures -XIT 
refer to the exits of the cranial nerves. 
Basisphenoid.--The basisphenoid covers the lower surface of 
the anterior part of the basioccipital, sending back processes over 
those of the basioccipital to form the tubera. They are continued 
forward as strong rounded ridges on each side of the bone which 
pass into the great basipterygoid processes, very well shown on 
R. 1870. These project downwards and outwards, leaving 
between them a deep channel on the under surface of the bone. 
They are of irregular shape, and the pterygoids articulate with a 
