398 



STERNUM OF THE LAUGHING GULL. 



are strong and well set, the clavicle wide, convex 

 anteriorly on the upper parts of its branches, but 

 recurved at their junction, and always united to the 

 keel of the sternum. The scapulars are sithe- 

 shaped, rather long, and of moderate breadth. From 

 its structure, this sternal apparatus indicates consider- 

 able power of flight, and also strength for resisting 

 pressure on the anterior part, though in this last 



Laughing GuH. 



respect it is much inferior to that of the entire footed 

 birds ; and in both it is very inferior to that of the 



