372 Annals of the South African Museum. 



wards. At the glenoid cavity the bone has a thickness of 17 mm. 

 Both the anterior and posterior borders of the blade are fairly thin 

 and keeled, but proximally the anterior border becomes thicker and 

 more rounded. 



Ulna. The right ulna is complete. Its length is 87 mm. The 

 proximal articular surface is triangular with an acute rounded anterior 

 angle, and an obtuse lateral angle. The posterior end stands higher 

 than the anterior. Below the proximal end the bone narrows rapidly. 

 In its proximal half the medial face of the bone has a shallow broad 

 longitudinal groove. Distally the bone is twisted and flattened so 

 that the broad faces of the distal end look directly forwards and 

 backwards. The distal end is 19 mm. broad. The medial end of 

 the articular surface is pointed, the lateral end truncate. The 



Fig. 20. Thecodontosaurus skirtopodus (Seeley). 

 Right ilium. 



maximum thickness at this surface is 11 mm. At its thinnest the 

 shaft is 12 mm. broad and 7 mm. thick. 



lliittn. The right ilium is typically Thecodontosaurian with its 

 short anterior spine and its elongate posterior spine. The length of 

 the upper border is 105 mm.; the border is slightly curved, more 

 so anteriorly than posteriorly. The posterior spine is more pointed 

 than in T. antiquus. On its inner surface the inner crest is strongly 

 developed. The acetabulum is 60 mm. broad and 30 mm. high. 

 The supra-acetabular crest is strongly developed above the anterior 

 part, but disappears posteriorly. The height from the postacetabular 

 process to the upper border of the bone is 76 mm. The preacetabular 

 process is 48 mm. long. 



Ischium. The distal end of a left ischium is 117 mm. long. The 

 shaft is slender, strongly expanded distally. The anterior edge is 

 straight and sharp, the posterior border regularly concave and flattened. 



