78 BULLETIN OF THE 



The humerus. The proximal end of this bone is not preserved in any of the 

 specimens ; the shaft is rather short and slender, and shows a distinct sigmoid 

 ctirve ; an indistinctly marked deltoid ridge runs for some distance down the 

 shaft. The distal end is moderately expanded and thorouglily cervine in ap- 

 pearance ; the inner condyle is much the wider, and the intercondylar ridge is 

 sharp and prominent. The anconeal fossa is deep and narrow, hut does not 

 perforate the bone. A moderate internal tuberosity forms a downward projec- 

 tion at the postero-intrt-nal angle. The ridges for muscular attachment are but 

 feebly developed. 



The radius is entirely distinct from the ulna, no co-ossification between the 

 two occurring at any portion of their length. The proximal end is much ex- 

 panded, as this bone carries nearly the entire weight of the fore limb, and cover-^ 

 the whole of the distal end of the humerus, the ulna being confined to the pos- 

 terior aspect. The groove for the intercondylar ridge is deep, and emarginates 

 the anterior and posterior edges. Two small facets for the proximal end of the 

 ulna occur on the posterior side, the inner one very small, the outer larger and 

 quite deeply concave. The shaft is long, slender, and considerably flattened, 

 forming in section a transversely directed oval. The distal end is expanded and 

 thickened, and is deeply grooved in front by the tendinal sulcus. On the ex- 

 ternal side there is a strong and roughened extension, which fits into a corre- 

 sponding depression in the side of the ulna. The facets for the carpus are 

 separated by a strongly defined ridge, and are placed very obliquely to the axis 

 of the bone. That for the scaphoid is deeply concave in front and as markedly 

 convex behind, and is continued well up on the posterior side of the bone. 

 This portion ha:, the greatest antero-posterior diameter. The lunar facet is 

 smaller and less deeply incised. External to it is a small oblique surface which 

 articulates with the cuneiform. 



The ulna is much reduced, though still retaining its independence. The ole- 

 cranon is rather short and much compressed, though of considerable fore and 

 aft depth. As the radius has usurped the entire distal end of the humeral 

 trochlea, the sigmoid notch of the ulna is shallow, and the internal radial facet 

 has become minute, though the external one forms quite a protuberance. The 

 shaft is exceedingly slender and compressed ; for most of its length hardly more 

 than a thread of bone. The distal end is somewhat expanded, though very 

 small, and deeply excavated on the inner side for the protuberance of the ra- 

 dius. The cuneiform facet is saddle-shaped, and sends down a well marked 

 process on the outer side. 



The pelvis, so far as it is preserved, is much like that of Cosorijx, though the 

 ilium has a longer neck, and was appprently even less everted than in that 

 genus. The ischium is rather short. 



Little of the femur is preserved. The head is small and compressed, and 

 rises little above the ridge connecting it with the great trochanter. The 

 rotular trochlea is very broad, with rounded and somewhat more prominent in- 

 ternal edge ; the outer edge is lower and sharper. The condyles are rather 

 small and widely separated ; above the inner one there is a small but distinct 

 plantaris rugosity. 



