272 



ZOOLOGY 



SECT. 



scribed (p. 84) in general terms as characteristic of the pentadactyle 

 Craniata. The scapula (Fig. 925, S, Fig. 926, scp) is ossified, and 



s.sc/a 



3C/t» 



Fig. 925.— Rana esculenta. The shoulder girdle from the ventral aspect. Cartilage dotted. 

 Co. coracoid ; Co' . epicoracoid ; CI. clavicle ; Ep, omostermim ; G. glenoid cavity ; Ft. fenestra 

 between clavicle and coracoid ; KC. cartilage separating scapula and clavicle ; Kii. xiphi- 

 sternum ; in, junction of epicoracoids ; S. scapula ; St. sternum. (From Wiedersheim's 

 Comparative A natomy.) 



is connected by its dorsal edge with a siq^ra. scapula (Fig. 922. s. 



SCP, Fig. 926, s. scp) formed partly of bone, partly of calcified 



cartilage, and developed from the dorsal region of the embryonic 



shoulder-girdle. The coracoid 

 (Fig. 925, Co., Fig. 926, cor.) 

 is also ossified, but the pro- 

 curacoid is represented by a 

 bar of cartilaoe having an 

 investing bone, the clavicle 

 (CI), closely applied to it. 

 The suprascapula overlaps 

 the anterior vertebrae ; the 

 coracoid and procoracoid are 

 connected ventrally by a car- 

 tilage, the epicoracoid (Fig. 

 925, Go', Fig. 926, ep. cor), 

 which is in close contact with 

 its fellow of the opposite side 

 in the middle ventral line, so 



that the entire shoulder-girdle (Fig. 926), like that of the Dog-fish, 



forms a single inverted arch. 



Passing forwards from the anterior ends of the united epi- 



Cfi.CCf 



FiQ. f»20. — Rana. Diagrammatic transverse 

 section through the shoulder-girdle. cor. 

 coracoid ; cp. cor. epicoracoid ; ;//. glenoid 

 cavity ; lin. humerus ; scj). sc;,pula ; .«. scp. 

 supra-seapula ; v. S, third vertebra. (From 

 Parker's Practical Zoolo(fi/.) 



