432 



Annals of the South African Museum. 



anterior half of the surface. There is thus a strong boss forming 

 an incipient olecranon process. The maximum length of the proximal 

 surface is 120 mm., its maximum width 60 mm. 



The posterior border of the bone is bent in an S-shaped curve, 

 the anterior border being regularly convex. In the former feature 

 the bone differs considerably from that of Plateosaurus erlenbergensis 

 which has a straight posterior border. The thinnest part of the shaft 

 occurs about 10 cm. from the distal end, where it has an oval cross- 

 section whose diameters are 35 mm. and 45 mm. The distal end 

 is 95 mm. broad. 



lli'inn. In the Thaba 'Nyama specimen one ilium is complete. In 

 the Rooi Nek specimen one ilium is complete and the other almost 

 so. The shape of the ilium is most like that of Massospondijlus carinatus. 



Fig. 44. Melanorosaurus readi, Htn. 

 Right ilium of type. X J. 



The upper edge is fairly straight and the anterior spine is not so 

 long as in Gresslyosaurus. The acetabulum is bounded in its upper 

 anterior quadrant hy a sharp ridge which dies away towards the 

 end of the preacetabular process. The postacetabular process is short; 

 its posterior border is straight, except at the lower corner, where it 

 is provided with a hook-like projection. The posterior iliac spine is 

 short and high. The body of the bone is slightly bowed inwards. 



The height of the bone from the bottom of the postacetabular process 

 to the upper edge is 275 mm.; the greatest length is 415 mm. The 

 width of the acetabulum is 210 mm., its height 120 mm. 



Pulls. An incomplete pubis is preserved, which shows that the 

 anterior portion is a broad, flattened plate. 



