THE OSTEOLOGY OF THE DIADECTIDAE 



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The pubis. — This is wide anteriorly and narrows slightly anterior 

 to the acetabulum. The pubic foramen is near the middle of the 

 bone. The anterior edge is nearly straight, but is slightly inclined 

 backward toward the middle line, so the edge is somewhat notched. 

 . The ischium. — This is narrower than the pubis and is sharply 

 contracted posterior to the acetabulum, which has on this bone a 



Fig. 19 Fig. 20 



Fig. 19. — Anterior view of humerus of specimen No. 1075. One-half natural 

 Fig. 20. — Anterior, lower view of femur of specimen No. 1075. One-half natural 



prominent rim. The posterior edge of the pelvis formed by the 

 two ischia is even more deeply notched than the anterior. 



The humerus. — This is a relatively short and wide bone, but of 

 the same general type as occurs in all of the Cotylosauria. There 

 is a very strong radial process reaching to near the middle of the 

 shaft, and a large entepicondylar foramen near the middle of the 

 lower end. The process for the head of the radius is broken away, 

 but the entepicondylar process is exceptionally wide and large. The 



