482 



GEOLOGY OF THE DENVER BASIN. 



anatomical features of great interest. In figs. 25 and 26 below, restora- 

 tions of the fore and hind legs, one-half natural size, are given, which show 

 well the delicate proportions of the animal. 



The scapula is of moderate length, and its upper portion broad and 

 thin. The humerus is slender, with a strong radial crest. The shaft is 

 very hollow, with thin walls, and the cavity extends almost to the distal 



Fig. 25.— Outline restoration of left fore leg of Hallnpus riclor Ma 

 Fig. 26. — Outline restoration of left hind leu of same individual. 

 Both figures are one-half natural size. 



end. The latter is but little expanded transversely. The radius and ulna 

 are short, and were closely applied to each other. There were but four 

 digits in the maims, the first being short and stout and the others slender. 

 All three pelvic bones aided in forming the acetabulum, as in typical 

 dinosaurs. The ilia are of the carnivorous type, and resemble in form 

 those of Megalosaurus. The pubes are rod-like, and projected downward 



