387 



proximal articular surface of the radius (PI. LXX. fig. 7) is circular, very shallow, at 

 right angles to the shaft or length of the bone. The articular smoothness continued 

 upon the periphery of the head is a little broader (ib. fig. 5, b) where it rotates upon the 

 lesser sigmoid cavity (ib. fig. 8, b) of the ulna, but is narrow where it plays upon the 

 " orbicular ligament." The so-called neck (ib. fig. 5, c) is long, and equals the shaft in 

 thickness. The tuberosity (ib. d) rises an inch below the head and is obliquely elongate ; 

 a ridge divides the raised rough surface next the ulna, for the insertion of the biceps 

 tendon, from the smoother tract occupied by the " bursa," intervening between the 

 tendon and the bone. The shaft is slender in proportion to its length, subtriedral at 

 the proximal third, subquadrate at the distal one (ib. fig. 6). The interosseous line is 

 scarcely developed into a border : it is traceable from behind the tuberosity, along the 

 ulnar side of the shaft, to the distal end, which expands to a little beyond the breadth 

 of the upper part of the shaft at the tuberosity (fig. 5, d). The distal articulation 

 (fig. 6, e) forms the broadest part of the bone. 



The ulna (ib. figs. 8 & 9) presents at its proximal end the two continuous articular surfaces 

 known in anthropotomy as the " greater " (a) and " lesser " (b) sigmoid cavities. The 

 greater is oblong and concave vertically, transversely convex, slightly emarginate on each 

 side. The lesser cavity is semioval, bent down at right angles with the greater ; it is 

 moderately concave ; it receives the head of the radius, as the greater cavity does the 

 trochlear part of the distal joint of the humerus. The angle between the articular sur- 

 faces, a and b, represents the " coronoid " process (c). Below this is an oblique ridge and 

 roughness (d!) for the insertion of the " brachialis anticus." The olecranon (e) extends 

 about an inch above the joint ; it is subcompressed and tuberous terminally. The shaft is 

 more compressed and develops a sharp " interosseous ridge" (ib. fig. 9,^) from its middle 

 third. The length of the ulna is 1 foot 3 lines ; its greatest breadth is 1 inch 2 lines ; 

 its distal end, like that of the radius, was in the epiphysial state (ib. fig. 10, 55) ; it ter- 

 minates by a " styloid process" which works in a pit of the " os cuneiforme " (ib. c). 



The fore paw is pentadactyle, with divergent and freely movable unguiculate digits. 



The carpus (ib. fig. 10) consists of a scapho-lunar (s I), cuneiform (c), and pisiform 

 (p) in the proximal row, and of the usual four bones in the distal row, of which the 

 unciform (u) is the largest, is interposed between the lunar part of the scaphoid and 

 the cuneiform, and supports part of the middle as well as the fourth and fifth digits. 

 The scapho-lunar (ib. fig. 10, s I) presents to the radius (ib. 54) a convexity trans- 

 versely elongate, broadest ulnad, the breadth there being one third the length ; nar- 

 rowing radiad almost to a point (s) : the curve of the convexity is bold in both direc- 

 tions, but greatest across or in the short diameter of the surface. The major part 

 plainly answers to the convex radial articular surface of the lunar bone in Man and the 

 Orang l . A non-articular surface, with irregular elevations and depressions on the 

 anconal (dorsal) surface of the bone, of a subtriangular form, exceeding in breadth that 



1 See 'Anat. of Vertebrates,' vol. ii. p. 541, fig. 361, 6. 



