777 



5126. The left radius. 



It differs from that of the Orang in being much shorter in proportion to its breadth, and 

 presents a more marked sigmoid curvature ; the borders of the circular proximal end are more 

 produced ; the trihedral character of the distal half is better marked. The distal end is more 

 suddenly expanded, and the grooves for the extensor tendons are deeper and better denned. 

 The anterior angle of the ulnar surface is more produced, and that surface is less depressed. 

 The medullary canal commences near the junction of the proximal with the middle third, at 

 the fore part of the bone, and inclines proximad. 



5127. The left ulna. 



This differs from the corresponding bone in the Oraug, and approaches that of Man in the 

 proportion of its length and thickness. The outer or ulnar division of the great sigmoid 

 cavity is less developed than in the Orang, and its margin is more extensively interrupted at 

 its middle part : the radial division of the same cavity extends more nearly to the back part 

 cf the olecranon. The lesser sigmoid cavity is more nearly semicircular than in the Orang. 

 The ridge continued a short way downwards from the inner and ulnar angle of the great sig- 

 moid cavity is sharply defined, but the fossa which it bounds is much less deep than in the 

 Orang. The interosseous ridge is not marked, the bone being there rounded off in the 

 Chimpanzee. The styloid process is better developed than in the Orang. 



5128. The right radius. 



This bone has been fractured at its middle part and united with thickening, but the ulna, 

 having, by means of its terminal attachments to the radius, acted as a splint, there has been 

 no shortening as in the humerus. 



5129. The right ulna. 



5130. The right scapho'ides . 



It is a single bone, not divided, as in the Orang. The radial surface is elongated, undu- 

 lating, nearly flat, and forms a right angle with the subquadrate trapezial convexity : they are 

 separated by a narrow groove, but both are continued into the concavity for the maguum. 

 The ulnar angle of the bone is produced into a well-marked tuberosity. 



5131. The lunare. 5132. The cuneiforme. 



5133. The trapezium. 



The outer end of the bone between the surface for the scaphoides and that for the thumb 

 is produced into a well-marked tubercle, and there is also a tuberosity on the back jiart of 

 the bone. 



5 G 



