602 



MAMMALIAN ANATOMY 



FIG. 461. 



is the continuation from the proximal surface of the narrow facet for 

 the ulna. The remaining triangular surface is rough for the attach- 

 ment of ligaments. 



The distal surface (Fig. 463) is slightly wider in the transverse 

 than in the dorso-palmar direction. Its palmar, dorsal, and radial 



borders are straight ; its ulnar border is arcuate 

 and oblique. Almost the entire distal surface is 

 occupied by a flat articular facet for the unciform. 

 This facet has a distinct emargiuation on the palmar 

 side for a rough pit in which is inserted the strong 

 ligament which passes to the ulnar surface of the 

 unciform. When the bone is in position the distal 

 surface faces as much to the radial side as down- 

 ward. 



The radial surface scarcely exists as a distinct 

 surface, since the proximal surface conies down on 

 the radial side almost to the distal surface, leaving 

 little more than a roughened border between the 

 dorsal and palmar surfaces. This border is united 

 with the ulnar border of the distal surface of the 

 scapho-lunar by a wide ligament. 



The dorsal surface (Fig. 460) is in the main 

 rectangular. It is wider than high, and the ulno- 

 distal angle is slightly produced. Its upper border 

 is arcuate and passes without an angle into the ulnar border, which 

 forms an acute angle with the almost straight distal border. The 

 radial border is curved, and the radio-proximal angle in most cases 



FIG. 462. 

 Palmar Side. 



POSITION OF CUNEI- 

 FORM. 



With Pisiform. 



Radial Side. 



With Ulna. 



Ulnar Side. 



Dorsal Side. 



LEFT CUNEIFORM, PROXIMAL SURFACE. 



is rounded off. The surface itself is gently convex, and rough for 

 ligamentous attachment. 



