28 1 



OSTEOLOGY OF TUBINA11ES AND STEGANOPODES. 



The shoulder-girdle (Fig. 23), due to the spreading furcula, is very 

 wide from side to side, and, due to the short coracoids, is rather squatty 

 in appearance. The furcula is one of the broadest among living birds, 



Fig. 22. Pectoral aspect of the sternum of Diomedea albatrus; life size. By the author, from specimen 



3333, Smithsonian collection. 



the shallowness of its U almost equaling that of the extinct Hesperor- 

 nis. Each clavicular limb is, compared with the other elements of the 

 arch, slender, and of nearly uniform caliber throughout. The heads 

 gradually taper out to a point posteriorly, and articulate with the cora- 

 coids and scapulae as they do in Rodgers' Fulmar, described above. 



The middle of this arch below is thickened, being concave in front 

 and somewhat produced behind, but bearing no proper hypocleidium, 

 the modifications being apparently intended to give a greater surface 

 for ligamentous attachment to the carinal angle of the sternum. 



In some specimens, when the girdle is articulated in situ, this part of 

 the furcula may rest against the apex of the angle of the carina, being 

 thoroughly strapped to it during life by ligamentous bands. 



It will be remembered, that anchylosis takes place at this point in 



