632 MAMMALIAN ANATOMY 



surface of the third metacarpal is near the dorsal border, the highest 

 point of that surface in this bone is behind the middle. The radial 

 part of the proximal surface of this bone is much lower than the ulnar 



FIG. 499. 

 Proximal End. 



With. Unciform. 

 With Third Metacarpal.-^k^ I \ With Fi - fth Metacarpal. 



yO 



.Radial Side. ^ >' j Ulnar Side. 



FOURTH LEFT METACARPAL, DORSAL SURFACE OF BASE AND 



PART OF SHAFT. 



part (Fig. 499), and has the appearance of a small shelf, while in the 

 third metacarpal the radial portion is as high as the general proximal 

 surface. 



The ulnar surface of the base (Fig. 500) does not project beyond 

 the ulnar side of the shaft, otherwise it closely resembles the corre- 

 sponding surface of the third metacarpal by presenting along the 



FIG. 500. 

 Proximal End. 



With Fifth Metacarpal 



Dorsal Side. P ' )\i Palmar Side. 



FOURTH LEFT METACARPAL, ULNAR SURFACE OF BASE AND 



PART OF SHAFT. 



proximal border a ridge which is wider behind than in front, and, 

 near the dorsal border, a crescentic pit which, like the ridge, is 

 covered with cartilage and articulates with the radial surface of the 

 base of the fifth metacarpal. Behind this pit the ulnar surface is 

 rough for the attachment of ligaments. 



The radial surface (Fig. 501), below and behind the radial part of 

 the proximal surface, is convex and rough for ligaments. 



The palmar hook (Fig. 502) is broader than in the third meta- 

 carpal, as is the rough space below it. 



