396 



E. C. CASE 



Fig. 2. — Scapula, epicoracoid, and epiclavicle of 

 Eryops latus, showing the complete cleithrum. clt. Left 

 side. 



Broili describes a scapula and coracoid in the same genus, but 

 evidently regards as coracoid the bone usually described as 

 epicoracoid, leaving the part here described as coracoid absent 

 or cartilaginous. Cope speaks of the coracoid as distinctly 

 recognizable, but figures no suture and describes the epicoracoid 



as probably present 

 but not recogniz- 

 able. There thus 

 seems to be con- 

 siderable difference 

 of opinion regard- 

 ing the presence of 

 the coracoid. From 

 considerations cited 

 below it seems to me 

 that the coracoid 

 was cartilaginous, 

 but if so the anterior 

 end of the scapula assumed a strikingly similar form to the 

 coracoid of the reptiles, sheltering the whole of the humeral 

 cotylus, which in the reptiles is shared between the coracoid and 

 scapula. 



In Eryops the antero-internal edge of the bone is thickened 

 and shows the previous attachment of a thick plate of cartilage. 

 This mark of cartilaginous attachment extends around the anterior 

 end -of the bone from the anterior end of the face for the humerus 

 to about the end of the anterior fourth of the upper edge, where 

 it terminates in a small but decided angle at the point where the 

 clavicle touched the scapula. Both the cartilaginous edge and 

 the angulation seem to be diagnostic characters of importance, 

 for in the reptiles they are absent. The coracoid of the Pely- 

 cosaurs has a sharp beak-like process and the anterior edge is 

 free from cartilage. The edge of the epicoracoid is thin and the 

 cartilage was either absent or small. In the Pelycosaurs the 

 coracoid is always distinctly separated from the scapula by suture, 

 and is apt to be a separate fragment in the specimen. In Eryops^ 

 the cotylus for the humerus is deeper and the anterior and pos- 



