AKTICLE VI. 



ON THE SHOULDEK-GIEDLE AND EXTEEMITIES OF EEYOPS. 



BY E. D. COPE. 



Read before the Ameiican Philosophical Society, January 20, 1888. 



Our knowledge of the genns Eryops, which is one of the most abundant types 

 of the Rhachitomous Batnichia, extends to the skull in general, the vertebral column, 

 the pelvis, humerus, femur, and tibia.* The shoulder-girdle, fore foot, and hind foot 

 are unknown, although the hind foot of a species from the coal measures provisionally 

 referred to this genus has been described.f In the present paper I can describe the 

 missing parts from a skeleton found with skull of the Eryops megaceyhalus, which 

 Avas obtained in Texas, in the Permian beds, by that indefatigable and skillful col- 

 lector, Jacob Boll. 



The shoulder-girdle embraces scapula, coracoid, prsecoracoid, clavicle, and epi- 

 sternum. The scapula is flat and elongate; its superior portion is rather thin, and gradu- 

 ally expanded and rounded like the end of a boat's oar. Below it passes directly into the 

 coracoid and praicoracoid, the suture becoming obliterated early. The prajcoracoid is 

 larger than the coracoid, is convex downwards, while the coracoid is convex upwards. 

 This leaves a fossa at their line of junction on both surfaces, and through this the cora- 

 coid foramen is pierced. The posterior border of the coracoid is regularly convex, and 

 is not notched as in the Pelycosaurian Theromora.J The internal and anterior bor- 

 der of the praicoracoid foi'in a continuum of convex outline, the former passing rather 

 abruptly into the latter. The clavicles are curved bones, forming, as usual, the ante- 

 rior border of the shoulder-girdle. Their superior portion is directed upwards and 



* Proc. Amer. Philos. Soc, 1880, p. 52. 



t Trans. Amer. Philos. Soc, 1886, p. 289. 



X Theromora is subsliluted for Theromorpha, a name which had been previously used. 



