90 



with the scaphoid is the shortest, that joined to the metacarpal bone is the 

 longest : towards the dorsal part of the carpus this surface is divided into two 

 parts by a rough depression ; on the opposite or palmar side a small portion of 

 the articular surface is bent outwards at a right angle, so as to support part of 

 the second metacarpal bone. The chief part of the proximal surface of the os 

 magnum is convex, and is received into the concavity of the os lunare. 



The unciform bone {g) has its flat dorsal surface bounded by five sides and 

 supporting an oblong protuberance extending from the radial margin to the 

 middle of the dorsal surface ; the letter g is placed on this protuberance in Plate 

 XV. Part of the radial side of the dorsal surface bounds a slight vacuity between 

 the unciforme and os magnum. The two proximal sides are nearly straight ; one is 

 formed by the dorsal margin of the articulation between the unciforme and the 

 lunare, the other by the more extensive one between the unciforme and cunei- 

 forme. The three distal surfaces are articulated with part of the base of the 

 third, fourth, and fifth metacarpal bones. The palmar side of the unciforme 

 presents, as its most strildng character, a wedge-shaped process, convex on both 

 sides, which is impacted in the interspace between the lunar and cuneiform 

 bones ; immediately below this process the surface is excavated, and then swells 

 out into a rough tuberosity, near the margins of the articular surfaces by which 

 the unciforme is united with the third metacarpal. This surface is divided from 

 that for the os magnum bji a narrow rough channel. The six articular surfaces 

 covering the rest of the circumference of the bone are uninterruptedly conti- 

 nuous ; so that the rough dorsal and palmar surfaces of the bone are connected 

 by a similar non-articular tract along the radial, instead of the ulnar margin. 



The pisiform bone is attached, as usual, by a single articular surface to the 

 cuneiforme, and unites with no other bone of the carpus, but it is articulated by 

 a narrow portion of the surface to the ulna. It is of an oval flattened form, rough, 

 convex, and traversed by a ridge on its outer side. 



The articular surface presented to the fore-arm by the scaphoid, lunar, and 

 cuneiform bones is curved obhquely so as to throw the hand inwards and bring 

 its outer or ulnar margin to the ground when used for supporting the trunk. 



The metacarpal bones progressively increase in length from the first to the 

 fourth ; the fifth is longer than the third, but this is the thickest of all. The 

 first metacarpal, or that of the pollex (m 1), presents a very singular and ano- 



