250 



VERTEBRATE SKELETON 



(fig. 265) the cartilage girdle is perforated by two or three fenestras 

 in the coracoidal part, one nearly in front of the glenoid fossa, and 

 one or two medial to these; sometimes the scapular part has a fenes- 

 tra. Two ossifications occur in this cartilage, one scapular, the 

 other in the posterior part of the coracoid region. The scapula 

 is continued dorsally by a cartilage (or sometimes ossified) supra- 

 scapula. The scapula frequently has a small acromial process. 

 The large coracoid contains the supracoracoid foramen, and its 



Fig. 265.- — Pectoral girdles of (A) Xantusia vigilis (Camp, '23); {B, C) Iguana 

 tuberculata (Parker, '68); and (D) Sphcerodactylus macrolepis (Noble, '21). c, coracoid; 

 cf, coracoid fenestra; cl, clavicle; cs, s, coraco-scapular fenestra; e, ec, epicoracoid; es, 

 episternum; g, glenoid fossa; /z, humerus; />, precoracoid; 5C, scapula; sf, supracoracoid 

 foramen; .S5, suprascapula; st, sternum; uc, upper coracoid fenestra. 



ossification usually extends to the bars between the fenestras and 

 into the glenoid region where scapula and coracoid fuse. The 

 arcuate cartilage (epicoracoid region) nearest the median fine remains 

 unossified, these parts of the two sides meeting dorsal to the epi- 

 sternum. The anterior part of the cartilage (sometimes replaced 

 by hgament), which limits the fenestra in front is probably pre- 

 coracoid, and this element may also include the lateral bar of the 



