OS MAGNUM. 121 



THE CUNEIFORM. 



The superior surface of the cuneiform is rough and 

 non-articular; the inferior surface articulates with the 

 unciform ; the external surface articulates with the semi- 

 lunar above and the unciform below. The internal sur- 

 face projects and affords attachment to the external 

 lateral ligament of the wrist. The dorsal surface is 

 rough for the attachment of ligaments. The anterior 

 or palmar surface presents an articular facet for the 

 pisiform bone. 



THE PISIFORM. 



The pisiform, about the size of a large pea, is co- 

 noidal in form ; its base presents an articular surface for 

 articulation with the cuneiform. 



TfcE TRAPEZIUM. 



The trapezium articulates superiorly with the scaphoid, 

 inferiorly with the first metacarpal bone, internally with 

 the trapezoid and base of the second metacarpal bone. 

 The palmar surface is grooved for the tendon of the 

 flexor carpi radialis. The dorsal surface is rough. 



THE TRAPEZOID. 



The superior surface of the trapezoid articulates with 

 the scaphoid ; the inferior surface articulates with the 

 second metacarpal ; the external surface articulates 

 with the trapezium ; the internal surface articulates with 

 the os magnum ; the anterior and posterior surfaces are 



rough. 



OS MAGNUM. 



The os magnum is placed in the centre of the osseous 

 palm ; the superior surface articulates with the semilunar; 

 the inferior surface with the third metacarpal principally, 

 also slightly with the second and fourth ; the external 



