SHOULDER-GIRDLE 



47 



From its I'bwer end two bones (Fig. 12, Cl, Co; Fig. ii, 

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

 in a plate of cartilage (Co^), which meets with its fellow 

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

 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. epi- and omo-sternum ; G. glenoid 

 cavity ; Fe. fenestra between procoracoid and coracoid ; KC. cartilage separating 

 scapula and clavicle ; Kn. xiphisternum ; in. junction of epicoracoids ; 5*. 

 scapula \ St. sternum. (From Wiedersheim's Comparative Anatomy.') 



broader and is known as \ki& 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. \2, G ; Fig. \\, gt), for the articulation of the 

 upper-arm bone. 



