BALyENOPTERA. 



49 



The cartilaginous surface of the glenoid was pro- 

 longed into a pointed coracoid. The humerus was 

 6^ inches long; its head was formed by a thick 

 cartilaginous epiphysis which represented also the 

 tuberosities. The synovial membrane lining the 

 capsule was reflected on to the free surface of the 

 cartilage. The lower end of the humerus also had an 

 epiphysial cartilage with no trace of ossification. 

 The radius with its epiphysis was 15^ inches long, 

 the ulna 14^. The ulnar upper epiphysis was con- 

 tinued into a cartilaginous plate 5 inches by 2 inches 

 which formed the olecranon. See Plate IV. 



At the carpal end the cartilaginous epiphysis of the 

 radius was distinct, that of the ulna was fused with two 

 of the carpal cartilages. The cartilaginous mass of the 

 carpus was subdivided by furrows which lodged bands 

 of fibrous tissue that marked off" its segments. In the 

 proximal row were radiale, intermedium, and ulnare ; 

 the radiale was large, and perhaps included a non- 

 difterentiated distal carpale ; the ulnare was only 

 partially difierentiated by a furrow, and entered into 

 the large cartilage continuous with the ulnar epiphysis 

 and the pisiform, the latter of which formed a band 

 parallel with the inner border of the lower end of the 

 ulna. In the distal row a long cartilage was opposite 

 the carpal ends of metacarpals iii. and iv., and doubt- 

 less represented C3+4 ; in the absence of the pollex 

 there was no C^ and no carpalia were difierentiated 

 for M ii. and M v. The four digits were ii. to v. Each 

 had an ossified metacarpal with carpal epiphysis 



