198 Annals of thk Carnegie Museum. 



what, however, in lying in the same plane with the general humeral 

 surface, below the ulnar crest, and not being situated at the base of a 

 ])neumatic fossa, in which several openings are usually seen leading 

 to the hollow shaft of the bone. From radial to ulnar side the prox- 

 imal enlargement of the humerus is not nearly as great as we find it 

 in many others of the Class. At its summit there is an oval, convex 

 facet for the glenoid cavity. This is separated from the ulnar crest 

 by a deep intervening valley, which appears all the deeper from the 

 great prominence attained by the former. 



The radial crest is, on the other hand, quite low, and not unusually 

 developed. It extends down the shaft only to the point where the 

 latter commences to assume the cylindrical form. On the palmar 

 aspect of the proximal end of the humerus we have a well-defined 

 trench extending across the bone, just behind the ulnar crest and 

 glenoid head. Another, fainter one, though pretty well marked in the 

 direction of the shaft, marks out the boundaries of a convex, sub-oval 

 and flattened space, on the lowermost side of the palmar aspect of the 

 proximal end of the bone, which is present in some form or another 

 in this place on the humerus, in a number of the Class. 



The shaft for the greater share of its length is cylindrical and smooth ; 

 the sigmoid curves it presents in the majority of birds are here well 

 marked. The distal extremity is dilated in the same plane nearly with 

 the proximal end, to give space for the guidance of muscular tendons 

 on the anconal side, which there pass over grooves marking the bone, 

 as well as affording the necessary breadth to support the ulnar and 

 radial tubercles on the i)almar side. Above the latter is seen a long, 

 subelliptical depression, running obliquely up from this dilated portion 

 to a point where the shaft begins to assume the cylindrical form. 



The radius is a non-pneumatic bone, and like all bones of this 

 character, in the ordinarily prepared skeleton becomes yellow, dark 

 and greasy, owing to the oily constituents of the contents of the 

 shaft gradually oozing through its walls. 



This bone, in common with its companion in the anti-brachium, 

 is considerably longer than the humerus. From proximal to distal 

 extremity its shaft is much bowed in the palmar direction. 



The proximal end is comparatively little enlarged ; it presents the 

 usual subelliptical facet for the humeral tubercle of the bone of the 

 brachium. On its end, and shaft-wise, the ulnar facet is presented for 

 our examination. 



