THE BONES. 85 



an inferior, concave, divided, articular surface, 1. Cavitas gknoidalis, for os navi- 

 culare, on the outside, os lunatum on the inside. 2. Externally : proc. styloideus, 

 for supinat. longus, between the anterior and external border, a groove, for m. 

 abduct, long, and extens. br.evis pollids. On the circumference upon the dorsal 

 aspect 3. Two grooves, for the tendons of the extens. carpi radial, long, and 

 brevior; anteriorly, for those of the extens. digit, comm., and behind, pollic. long. 

 Incisura semilunaris, in which the Capitulum Uliia> moves. 



Development proceeds from three osseous points, first in the 

 central piece ; in the inferior extremity, towards the third year, 

 in the superior towards the ninth; the last unites with the shaft 

 in the twelfth year ; the first in the eighteenth to the twentieth. 



99. IV. Ossamanus, Bones of the hand. 



1. Carpus, root of the hand, wrist, about an inch long, 2-i 

 broad, consists of eight short bones, lying close together in two 

 rows, one above the other, and four bones in each. The wrist is 

 united above, with the fore-arm ; below, with the metacarpal 

 bones ; concave upon its anterior or palmar surface, hollow of 

 the hand, it forms with the ligam. carp, volare prop., a ring for 

 the tendons of the flexor muscles ; convex on the posterior, dor- 

 sal surface. It presents an Ulnar and Radial border, Vola, pal- 

 mar Dor sum manus, dorsal surface, back of the hand. 



Eminentix carpi are two projections on either border of the 

 palmar surface. 



At the ulnar border: 1. the superior, os pisiforme ; 2. the 

 inferior, the hooked process of the unciform bone. 



At the radial: 1. the superior, os naviculare ; 2. the inferior, 

 os trapezium. 



a. Bones of~the superior row passing from the Radial to the 

 Ulnar border. 



1. Os naviculare s. Scaplioidcum lies below the radius, above three bones of 

 the second row, with a deep, articular fossa, for os Maguum, with a convex, 

 articular surface, for oss. traptziunt tt trapezoid., the largest bone of the first 

 row. 



2. Os lunalum, semilunare, lunar bone, lies below the radius above the os 

 magnum, between 1. and 3. 



3. Os [cuneifurme] triqudrum, pyramidal bone, below the Ulna, above the 

 unciform bone. 



These three bones, when united, are convex above, concave below. They 

 are connected with the fore-arm. 



4. O.i pisifurme, pea-like bone, for flex, carpi ulnaris, abduct, digiti 5, lies 

 free in the hollow of the hand, only united with the pyramidal bone [cunei- 

 form] at the ulnar border. 



b. Bones of the inferior row from the radial to the ulnar border. 



