446 Br. C. W. Andrews — The Fore-limb of Metriorhynchus. 



articulated with the plate-like first metacarpal and perhaps partly 

 supported the second. 



The ulnare(d) is an oblong bone articulating with the ulna proximally 

 and having a facet at the lower end of its anterior border for union 

 with the radiale : distally it supported the third, fourth, and fifth 

 metacarpals and to some extent the second. 



The first metacarpal (mc.l.) is a thin, much expanded bone, probably 

 triangular in outline when complete : it articulates with the convex 

 border of the radius only. The second metacarpal, which is rather 

 longer, is a narrow, compressed bone, expanding a little at its upper 



mcK 



Fig. 2. — Left fore-paddle of Metriorhynchus. a. radius; b. ulna ; c. radiale ; 

 d. ulnare ; h. humerus ; mc. I-V, metacarpals. Two-thirds nat. size. 



end, which articulated between the radiale and ulnare. Distally it 

 terminates in a sharp edge and probably had no phalange articulating 

 with it. The third metacarpal is larger but otherwise similar : it 

 articulates with the ulnare only. The fourth is about the same 

 length as the second, but is considerably more slender. The fifth is 

 about as long as the fourth, but has a more slender shaft. It has 

 a marked expansion at each end, and distally bears a facet presumably 

 for a phalange, the only one which appears to have been present. 



The paddle of Metriorhynchus, as compared with that of Geosaurus, 

 does not seem to have undergone such extreme modification especially 



