NATURAL SCIENCES OF PHILADELPHIA. 187 



other only at their proximal extremity, being barely in mutual 

 contact at the wrist ; but in consequence of their straightness, 

 their edges lie parallel in the continuity not presenting the ellip- 

 tical interspace commonly seen in birds' forearms. 



The radiale is not specially noteworthy (Fig. 7), being a simple, 

 somewhat cubical nodule with distal and proximal articular con- 

 cavity for the metacarpus and radius respectively, another articu- 

 lar face for the protuberance of the ulna, two free faces, and an 

 anterior extremity for tendinous attachment. The ulnare, on the 

 other hand, is of extraordinary, if not unique, shape and size. It 

 develops an immense lamellar expansion of the curious shape 

 shown in the figure, the real body of the bone appearing as a mere 

 process wedged in betwixt the ends of the ulna and metacarpus. 

 If, as I presume, the flexor carpi ulnaris has its customary inser- 

 tion into this bone, the increase of leverage must be enormous. 



The single metacarpal bone is peculiar in several respects. It 

 bears no pollical phalanx, and the crest that ordinarily indicates, 

 in the composition of this bone, the originally distinct radial met- 

 acarpal is here obscure, not being differentiated to any consider- 

 able degree from the general laminar expansion. The ulnar 

 metacarpal has no convexity; its fusion with the main metacarpal 

 is perfect for nearly its proximate half, and again at the distal 

 extremity a narrow linear fenestration separating it in the rest 

 of its extent. The head of the bone represents one continuous 

 articular surface for the radiale and ulnare, flat sideways, strongly 

 convex fore and aft. At the distal extremity, however, there are 

 two perfectly distinct articular facets an oval one for the radial 

 phalanx, and a small circular one for the ulnar phalanx. The bone 

 is nearly three inches long, and rather less than one-third as broad. 



The proximal radial phalanx is a straight, flattened, rectangu- 

 lar blade of bone, with four sharp corners, a sharp anterior and 

 posterior border, and an oval articular surface at either end. It 

 is two inches long and half an inch broad. The distal phalanx is 

 simply a flattened spur, with sharp edges, tapering to an obtuse 

 . point; it is about half an inch long. The ulnar digit, however, is 

 of unusual size, reaching beyond the end of the proximal radial 

 phalanx. It lias a stoul, head, whence a process is developed, and 

 then tapers regularly to the end. It is less obviously flattened 

 than the other bones of the hand. 



The bones of the leg conform closely to the general pygopodous 



