70 



THE SKELETON OF THE CAT. 



ScapJioliinar Bone. Os scapJiobinaris (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. 



Ciineiform Bone. {Os triqnetriim BNA) (Fig. 51, b). — 

 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 hamatnin 



BNA) (Fig. 51, g). — The unciform is 



a wedge-shaped bone with the apex 



CARPUS, AND PuALANGEs, of the wcdgc dlrcctcd proximad, and 



Dorsal Surface. smooth for articulation with the 



a, scapholunar bone ; l>, . r -^ 1 



cuneiform; ^, pisiform;^, trape- scapholunar. By a part of its ulnar 



zium; e, trapezoid; /, os mag- gurface it articulates with the cunei- 



num; g, unciform; h, radial i , . i- i r -in 



sesamoid; /.proximal phalanges; form, and by its radial Surface Wltll tlie 

 J, second phalanges; /', distal ^^ niat^num. Its distal end articulates 



phalanges; I, 2, 3, 4, 5. meta- . , ^ ^ ,, , cr.i ^ 1 



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



^'^^' Os magnnni. {Os capitat7im 



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



Fig. 51. — Cari'US, 



Meta- 



