Uuene and Lull — Triassic Reptile Hallopus. 115 



Ilium. — Both ilia are preserved, one of them showing the 

 inner, the other the outer surface. They are a little different 

 from Marsh's figure, because he omitted the very sharp anterior 

 edge of the spina anterior. Both ilia taken together complete 

 each other, because in one of them the anterior and in the 



Fig. 1. (?left) Scapula, natural size. The articular end is the upper one 

 in the figure with the processus deltoideus at the right upper corner. 



Fig. 2. Ileum, natural size. The spina anterior is at the right side of 

 the figure. The outlines are a combination of both ilia. The acetabulum 

 was probably nearly or quite closed. 



Fig. 3. Sacrum, seen from above. Natural size. The first sacral verte- 

 bra is at the top of the figure. The dotted lines are reconstructed exactly 

 the same size as fig. 2 (ileum) to show that there must have been three 

 sacral vertebrae. Drawn from the small slab. 



Fig. 4. Eight pubis, natural size. Partly reconstructed (dotted line). 



other the posterior part is missing. The processes pro- and 

 post-acetabularis are short and directed downward. The ilium 

 extends very far back and nearly as far forward. 



Length of (restored) ilium 45mm 



Height of processus post-acetabtdaris 12 



Width of acetabulum _ V 



Marsh thought the two sacral vertebrae were the complete 

 sacrum, but upon comparing the measurements with those of 

 the ilium we find that there were, necessarily, three sacrals. Our 

 reconstruction of the sacrum is given in fig. 3. 



Pubis and Ischium. — There is one broad and two long and 

 slender bones belonging to the pelvis. Marsh took the former 

 for the ischium and the rod-like bones for pubic bones. We 



