156 MR. D. M. S. WATSON ON THE 
Despite this large amount of work, practically nothing is known 
of the detailed structure of the skull, and I was therefore very 
pleased to find that a fossil I collected on the farm Hottentots 
Rivier, Gouph, Beaufort West, Cape Colony, would enable me to 
give a nearly complete description of the skull. With this 
description Pariasaurus becomes, on the whole, the best known 
Permian vertebrate. 
The material I have used consists of :— 
J. A skull from Hottentots Rivier. This apparently belongs 
to the same species as the skeleton in the South African Museum 
described by Broom as P. serridens, a species to which it certainly 
does not belong. It differs from P. baini in many features of the 
skull and skeleton, and is probably quite worthy of generic rank. 
This specimen consists of the entire brain-case, which has been 
very completely cleaned inside and out, the posterior part being 
divided by a sagittal cut, and the anterior part sliced through 
horizontally. The whole of the right side of the skull-roof is very 
perfectly preserved, and the fragment extends so far across the 
middle line as to give the shape of the skull and the complete 
structure with certainty. The sutures are shown only on the 
inner surface. ‘The palate is missing. 
IT. No. 49426, British Museum (Natural History), is the skull 
of the specimen collected by T. Bain at Palmiet Fontein, Dist. 
Beaufort West, described by Seeley as P. bombidens. His 
lithographic figures give a good idea of the specimen, which, 
however, has been very much more developed, the palate having 
been completely freed from the stone on both palatal and dor sal 
surfaces and the lower jaw disarticulated. 
Many, but not all, Prof. Seeley’s sutures are correctly deter- 
mined, and it is certain that the structure is essentially similar to 
that of specimen I. 
III. R. 1970 is the Tamboer Fontein specimen of P. bombidens 
collected by Prof. Seeley ; it shows the entire structure of the 
palate well-preserved and perfectly prepared, the sutures being 
visible on the dorsal surface. 
Description oF SKULL, drawn mainly from the Hottentots 
Ltivier specimen; others are indicated when used. 
The bones of the brain-case are fused into a single mass of 
bone in which sutures are not distinguishable. ‘The various 
regions are, however, readily identified, and are used in the 
following account. 
Basioccipital. —The basioccipital 1 is a large bone whose posterior 
end forms the condyle. This is almost exactly circular, but its 
border is slightly depressed below the foramen magnum. ‘The 
outer part of the condyle is rounded, but the centre is depressed 
into a deep conical notochordal pit exactly similar to that which 
occurs in every vertebral centrum of the animal. ‘The condyle is 
separated off from the body of the bone by a neck formed by a 
