412 



MANUAL OF ZOOLOGY 



SECT. 



the dorsal region of the embryonic shoulder- girdle. The 

 coracoid (Fig. 233, Co.) is also ossified, while the procoracoid is 

 represented by a bar of cartilage, having a membrane bone, 

 the clavicle (Cl.) closely applied to it. The supra-scapula 

 overlaps the anterior vertebrae ; the coracoid and procoracoid 



Kn, 



FIG. 233. Rana esculenta The shoulder girdle from the ventral aspect. Co 

 coracoid ; Co', epicoracoid ; Cl. clavicle ; G. glenoid cavity ; Ep. episternum 

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

 and clavicle ; Kn. xiphi-sternum ; m. junction of epicoracoids ; 5". scapula 

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



are connected ventrally by a cartilage, the epicoracoid (Co') 

 which is in close contact with its fellow of the opposite side 

 in the middle ventral line, so that the entire shoulder-girdle, 

 like that of the Dog-fish, forms a single inverted arch. 



Passing forwards from the anterior ends of the united 

 epicoracoids is a rod of bone, the episternum (Ep.} tipped by 



