GENERAL CHARACTERS OF BIRDS 



729 



The ilia of the pelvis may he firmly fused to the complex 

 sacrum ; the acetabulum is incompletely ossified ; the pubes 

 are directed backwards parallel to the ischia. There is no 





MT.I^ 



IT g ' 



HI 



IS 



Fig.- 430. — Fore-limb and hind-limb compared. 



H., Humerus ; R., radius ; U., ulna ; r., radiale ; u., ulnare ; C, distal 

 carpals united to carpo-metacarpus ; CC, the whole carpal region ; 

 MCI., metacarpal of the thumb ; /., phalanx of the thumb ; MC.II., 

 second metacarpus ; //., second digit ; MC.III., third metacarpus ; 

 ///., third digit. P., Femur ; T.T., tibio-tarsus ; Fi., fibula ; Pt., 

 proximal tarsals united to lower end of tibia ; dt., distal tarsals united 

 to upper end of tarso-metatarsus [T.MT.) ; T., entire tarsal region ; 

 MT.I., first metatarsal, free ; I. -IV., toes. 



pubic symphysis except in the African ostrich (Struthio), and 

 no ischiac symphysis except in the American ostrich (Rhea). 

 In the hind-limb the fibula is incomplete, and more or less 

 united to the tibia ; the proximal tarsal bones are united to 



