REPTILIA : SEYMOURIA 



57 



little outward. This ascending part is thin on the ascending 

 outer convex border, its anterior surface looking outward at an 

 angle of nearly forty-five degrees, to near the top, where the bone 

 is continued more slenderly quite to the upper angle of the clavicle, 

 touching or articulating with the front border. For the greater 

 part of its extent the thin border projects out from the scapula, 

 and is not applied to its outer face. On neither side is there any 

 indication of a cleithrum, and as no indications of this bone were 

 found by Broili in his specimens, I think it may be said definitely 

 there was none. In its absence the genus is differentiated from 

 both Diadectes and Lim- 

 noscelis and allied to 

 Labidosaurus. The right 

 scapula lies very perfect- 

 ly in place and is visible 

 in nearly its whole ex- 

 tent from without, save 

 the lower front angle 

 overlain by the clavi- 

 cle. On the left side it 

 is thrust back more, and 

 is partly hidden beneath 

 the overlying humerus. 

 The blade of the scapula 

 is considerably broader 

 above than below; its 

 posterior border is rather deeply concave, its anterior thin, and 

 the upper end is truncate, thicker posteriorly, for cartilage. The 

 suture separating the scapula from the coracoid, as in other ver- 

 tebrates from Texas where it has been observed, passes forward 

 from just above the posterior glenoid facet, through the middle 

 of the anterior facet, to the front border rather high up. The 

 supraglenoid fossa is rather broad and has at its upper part the 

 usual supraglenoid foramen. The glenoid fossa is short antero- 

 posteriorly, truncated posteriorly, with a cartilaginous border, very 

 much as in Varanosaurus, as figured in Plate V. It is evident that 

 here too the real, so-called coracoid was never ossified, but remained 



FIG. 20. Seymouria baylorensis. Pectoral girdle, 

 from below, one-half natural size, cl, clavicle; ;V, 

 interclavicle; c, coracoid; sc, scapula. 



