306 



THE AMERICAN NATURALIST 



[Vol. XL 



10, Gl.) being rather deep to receive the rounded head (//'.) 

 of the humerus {H.). The center of the coracoid is perforated 

 by an irregular aperture of varying size (F.), called by Osawa 

 the " supracoracoid foramen." 



The scapula and suprascapula (Fig. 10, Sc., S. Sc.) form, to- 

 gether, a spatula-shaped structure whose area is small in com- 

 parison with that of the coracoid, with which it is firmly united. 

 The suprascapula forms the blade of the spatula, and is a broad,, 

 thin sheet of cartilage, somewhat curved to conform to the curva- 

 ture of the side and back of the animal's body. The scapula is 



an elongated, somewhat flattened structure, slightly enlarged at 

 one end, where it is attached to the suprascapula, and considerably 

 enlarged at the other, where it is attached to the coracoid. It is 

 the only part of the shoulder girdle that is composed of bone. 

 The humerus (Fig. 10, H.) is rather thick in proportion to its 



