132 



Annals of the South African Museum. 



the humerus, when compared with that of P. haini, is seen to differ 

 in having a much less pronounced ridge above the outer condyle on 

 the back of the bone. Otherwise they agree closely. 



The Eadius and Ulna, 



The radius and ulna in this skeleton of Pareiasaurus serricUns 

 differ so greatly from those described and figured in P. haini that, 

 had they been found alone, they might very readily have been referred 

 to a new genus. In the ulna of P. baini the most striking character- 

 istic is the exceedingly well-developed olecranon process which clasps 

 round the articular surface of the humerus behind. The ulna of this 

 skeleton, though it has the upper end well developed, does not form 

 a distinct socket for the humerus. The upper end of the bone shows 

 no sign of fracture, and there does not even appear to have been an 

 epiphysis. The contours of the bone will be better understood from 

 the drawing. In the drawing a small process which lies to the outer 

 side of the head of the radius has been restored, having been injured 

 while the bone was being developed. 



The radius, when compared with that of P. haini, differs almost as 

 much as the ulna. As the ulna and radius were found together, 

 there is no possibility of any error either as to the radius being right 

 or left, or as to which is the upper end. The upper end has an 

 articular surface which forms a broad, irregular, oval, shallow^ 

 concavity. The ovoid surface is broader at the outer than the 

 inner side. The lower end of the bone forms an irregular triangular 

 articulation, one angle of the triangle being directed inwards. Above 

 the lower articulation the back of the bone is distinctly hollowed out. 

 A small inward process is formed just above the inner angle of the 

 articulation, and a little above it on the front of the bone is a 

 muscular depression. A distinct knob is found a little above the 

 lower articulation near the middle of the front of the bone. 



A considerable number of isolated phalanges and metacarpals have 

 been found, but without any indications as to which digits they 

 belong to. 



Pelvis. 



The pelvis is almost complete and very little crushed. The- 

 appearance it presents is therefore very different from that in the 

 skeleton of P. haini, described and figured by Seeley. Each side 

 consists of an ilium, pubis, and ischium. As the ilium lies almost 



