Ill 



SHOULDER-GIRDLE 



47 



From its lower end two bones (Fig. 12, C7, Co-, Fig. n, 

 cor) pass directly inwards, parallel with one another, to end 

 In a plate of cartilage (Co 1 }, which meets with its fellow 

 of the opposite side in the middle line of the chest (m). 

 The more anterior of these (Cl) is a narrow bone and 

 is called the clavicle or collar bone ? the posterior one is 



FIG. 12. The shoulder-girdle of the Frog from the ventral aspect. 

 Co. coracoid ; Co', epicoracoid ; Cl. clavicle : Ep. omo-sternum ; G. glenoid cavity ; 

 Fe. fenestra between clavicle and coracoid ; KC. cartilage separating scapula 

 and clavicle ; Kn. xiphisternum ; in. junction of epicoracoids ; 6". scapula ; 

 St. sternum. (From Wiedersheim's Comparative Anatomy.} 



broader and is known as the coracoid (Co). Between the 

 scapula on the one hand and the clavicle and coracoid on 

 the other, there is a cartilaginous interval (KC\ the posterior 

 edge of which is scooped out into a depression, the glenoid 

 cavity (Fig. 12, G ', Fig. n, gt), for the articulation of the 

 upper-arm bone. 



