598 MAMMALIAN ANATOMY 



emarginate, the emargination limiting the concavity for the styloid 

 process of the radius. 



The dorsal surface (Fig. 457) is triangular; the base of the 

 triangle is at the proximal side, and the apex points distally. The 



FIG. 457. 

 Proximal Side. 



With Radius. 

 With Sesamoid.\ 



Radial Side. '- ^- n ' UhCunei f orm - Ulnar Side. 



ith Unciform. 



With Trapezium. With With Magnum. 



Trapezoid. 



Distal Side. 



LEFT SCAPHO-LUNAR, DORSAL SURFACE. 



proximal border is rounded, allowing the surface to pass insensibly 

 into the proximal surface above. The outer or radial border is emargi- 

 nate, to receive the trapezoid. Its inner or ulnar border presents two 

 emarginations, which are the edges of the articular cavities for the os 

 magnum and the unciform, situated on the distal surface of the bone. 

 The dorsal surface of the scapho-lunar is gently convex from side to 

 side, and roughened for the attachment of ligaments. 



The distal surface (Fig. 458) is irregular, and exhibits four second- 

 ary articular surfaces, which are covered with cartilage and articulate 



FIG. 458. 

 Dorsal Side. 



With Trapezoid. 



/ . With Magnum. 



Radial Side ff 1 ** J^ /> * Ulnar Side - 



JM. 'mt/*ff ;/ ^~ With Unciform. 



With Sesamoid.A^^^J^(j 



With Trapezium. 



Palmar Side. 



LEFT SCAPHO-LUNAR, DISTAL SURFACE. 



with all the distal carpal bones. The smallest of these facets occupies 

 the greater part of the under surface of the process of the bone. It is 

 triangular, almost flat, and joins the proximal surface of the trape- 

 zium. Behind this area is a larger facet for the trapezoid ; this is also 



