196 SKELETON. 



be mistaken. Its ulnar side is flat, and presents a plane surface 

 for articulating with the unciforme. The radial side is uneven 

 and rather indistinctly marked where it joins the trapezoides, 

 but the latter surface will be found near the middle of this side 

 just below the head. The upper surface of the magnum is 

 formed into a spherical head, the radial side of which reposes 

 in the concavity of the scaphoides, while the ulnar side is in the 

 concavity of the lunare. Its metacarpal surface is triangular, 

 convex, and winding, by which it joins the metacarpal bone of 

 the middle finger. On the radial side of this surface is a small 

 one continuous with it, whereby the magnum articulates par- 

 tially with the metacarpal bone of the fore finger. The poste- 

 rior or dorsal face is broad, while the palmar is more narrow. 



Of the Unciforme, (Os Crochu.) 



It is placed at the ulnar side of the magnum, is nearly of the 

 same size, but readily distinguishable from it by its long crooked 

 process as well as by its peculiar shape. Its radial side is plane 

 where it joins the magnum; the reversed or ulnar side is brought 

 to a thin edge. The metacarpal surface presents two distinct 

 concavities ; the one next to the ulnar edge is for the metacarpal 

 bone of the little finger, and the other for that of the ring finger. 

 The upper surface is convex and winding, having its ulnar mar- 

 gin almost touching the surface of the metacarpal bone of the 

 little finger. The most considerable portion of the upper sur- 

 face reposes upon the cuneiform, and the remainder upon a 

 part of the concavity of the lunare. The posterior face is broad 

 and rough, while the palmar is narrower. From the ulnar side 

 of the latter, projects the unciforme process already alluded to. 



The two ranges of carpal bones, thus shaped, present, when 

 articulated or united together, an oblong body, the greatest dia- 

 meter of which is transverse. Its posterior face is semi-cylin- 

 drical and arched, while the anterior face is concave for the 

 passing of the flexor tendons. Two protuberances are found on 

 each extremity of the palmar surface. Those at the ulnar end 

 are the pisiforme, and the unciform process of the unciforme; 

 those at the radial end are the protuberance at the radial end of 



