32 THE ANATOMY OF VERTEBRATED ANIMALS. 



termed the centrale ; on the distal side of this are five car- 

 joalia, or tarsalia, which articulate with the several metacar- 

 pal or metatarsal bones; while, on its proximal side, are 

 three bones — one radlale or tibiale, articulating with the radi- 

 us or tibia ; one ulnare or fibtdare, with the ulna or fibula ; 

 and one intermedium, situated between the foregoing. Car- 

 pal and tarsal bones, or cartilages, thus disposed are to be 

 met with in some Amphibia and Chelonia (Fig. 11), but, 



Fig. ]1. — The right fore-foot of the Chelonlan CheJydra, and the righthind-foot of the Am- 

 phibian Suh'mandra. — U^ ulna; 7?, radius; i'', libula; y, tibia. 



Prcxioiiil carpa! bones: r, radiale; i, intermedium ; w, ulnare; the eentmle is the middle 

 unlettered bone. 



Proximal tarsal bones; t, tibiale; ?", intermedium; /, fibulare; c, centrale; 1, 2,8,4,6s 

 distal carpalia and tarsalia ; i, li, ui, iv, v, digits. 



commonly, the typical arrangement is disturbed by the sup- 

 pression of some of these elements, or their coalescence with 

 one another. Thus, in the carpus of man, the radiale, inter- 

 medium, and ulnare are represented b}' the scaphoides, lunare, 

 and cuneiforme respectively. The pisiform,e is a sesamoid 

 bono developed in the tendon of the flexor cafp>i idnaris, 

 which has nothing to do with the primitive carpus. The 

 centrale is not represented in a distinct shape, having proba 

 bly coalesced with one of the other elements of the carpus. 

 The fourth and fifth carpalia have coalesced, and form the 

 single imciforme. In the tarsus of man, the astragalus repre- 

 sents the coalesced tibiale and intermedium ; the calcanexun 

 the fibulare. The naviculare is the centrale. Like the cor- 



