THE ENDOSKELETON 721 



MAMMALIA 



The coracoid portion of the pectoral girdle (Fig. 416) is reduced 

 to a small coracoid process in all placentals, while the scapula of all mam- 

 mals possesses a spinous process. 



There are usually paired clavicles and a median unpaired interclav- 

 icle in all land mammals. These are membrane bones. 



