THE SKELETON OF THE CAT. 



ScapJwlunar Bone. Os scqpholunaris (Fig. 51, a]. The 

 scapholunar is a quadrangular bone with the ventroradial angle 

 produced into a blunt process. Its proximal surface is smooth 

 and articulates with the distal end of the radius. The distal 

 end is marked by oblique ridges and articulates with the unci- 

 form, os magnum, trapezoid, and trapezium. The ulnar surface 

 articulates with the cuneiform, and the dorsal surface of the 

 ventroradial process with the radial sesamoid. 



Cuneiform Bone. (Os triquetrum BNA} (Fig. 51, ). 

 The cuneiform bone has the form of a flattened pyramid. Its 



base articulates with the unciform, its ' 

 proximoulnar surface with the pisiform 

 except at its dorsal margin, where it 

 articulates with the styloid process of 

 the ulna. On its proximoradial sur- 

 face is a smooth facet for articulation 

 with the scapholunar. 



Pisiform Bone. Os pisiforme 

 (Fig. 51, c]. The pisiform bone is 

 about twice as long as broad, with 

 enlarged ends. Its dorsal end articu- 

 lates with the cuneiform, and on its 

 proximal surface, separated from the 

 above by a smooth ridge, is a smooth 

 facet for articulation with the styloid 

 process of the ulna. 



Unciform Bone. (Os Jiamatum 

 BNA] (Fig. 51, g). The unciform is 



a wedge-shaped bone with the apex 

 FIG. 5 1. CARPUS, META- 

 CARPUS, AND PHALANGES, of the wedge directed proximad, and 

 DORSAL SURFACE. smO oth for articulation with the 



a. scapholunar bone ; b, 



cuneiform; *, pisiform ; </, trape- scapholunar. By a part of its ulnar 

 zium; e, trapezoid; /, os mag- sur f ace it articulates with the cunei- 



num; g, unciform; /i, radial 



sesamoid;?, proximal phalanges; form, and by its radial surface with the 



j second phalanges; k distal magnum . I ts distal end articulates 



phalanges; I, 2, 3, 4, 5, meta- 



carpals in order from the radial with the fourth and fifth metacarpals. 



Os magnum. (Os capitatum 

 BNA\ (Fig. 51, f\. The os magnum may be described as an 



