THE SKELETON IN BIRDS. THE PELVIC GIRDLE. 339 



PELVIC GIRDLE. 



Birds have a very large pelvis and its characters are 

 constant throughout almost the whole group. The ilium 



FIG. 64. BONES OF THE EIGHT WING OF 



A. A PENGUIN x ^. (Camb. Mus.) 



B. OSTRICH (Stnithio camelw)x. (Partly after PARKER.) 



C. GANNET (Sula alba) x ^. (Camb. Mus.) 



In C the distal phalanges of the pollex and second digit have been 

 omitted. 

 1. humerus. 6. pollex. 



radius. 7. second digit, 



ulna. 8. cuneiform, 



second metacarpal. 9. sesamoid bone, 



third metacarpal. 



is very large, and is united along its whole length with 

 the sacral and pseudosacral vertebrae. The ischiurn is broad 

 and extends back parallel to the ilium with which in most 



222 



