CHAPTER IV 



THE PECTORAL AND PELVIC GIRDLES 

 The Pectoral or Shoulder Girdle 



(Figs. 95-113) 

 Those bones which form the framework for the support of the an- 

 terior extremities in vertebrate animals are collectively called the 



Cledkrum'^ 



lltetacorobCQidj 



irrf-erclavtcte 



Fig. 95, Diadectes (Cotylosauria). Pectoral girdle, right side. 



pectoral or shoulder girdle. In our own skeleton, as in that of most 

 mammals, there are but two on each side, the scapula, or shoulder- 

 blade, and the clavicle, or collar-bone. A third bone, or possibly two, 

 on each side, are represented in most mammals by mere vestiges, 

 which early unite with the scapula to form the coracoid process. In 



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