Occasional Papers of the Museum of Zoology 3 



The animal possessed a broad scapula quite different in 

 form from that of Dimetrodon. There is a small splint-like 

 cleithrum, the clavicle is shorter and heavier than in Dime- 

 trodon, the interclavicle has a stouter anterior end but a simi- 

 lar, elongate posterior projection. The humerus is quite like 

 that of Dimetrodon in general form but possesses an ectepi- 

 condylar as well as an entepicondylar foramen. The lower 

 arm bones are decidedly shorter and heavier than in Dime- 

 trodon. The pelvis lacks the strong posterior prolongation of 

 the ilium ; instead, this bone is flared out into a broad, flat sur- 

 face with a deeply grooved inner surface for cartilaginous at- 

 tachment to the two sacral ribs. The femur has the bicipital 

 groove extending further down the anterior face, bounded by 

 strong ridges. The lower leg bones are short and heavy. No 

 specimen has been found in which the feet are preserved and 

 in the mount the feet are modeled after those of Dimetrodon. 

 There is some reason to think that this is not correct and the 

 arrangement is regarded as provisional. Certain very large 

 and heavy claws found in the bone bed and in all probability 

 not belonging to Dimetrodon may belong to Edaphosaurus. 

 The ribs show that the animal had a fairly heavy body which 

 was probably increased by the large size of the visceral cavity. 

 That the tail was fairly long and provided with a distinct 

 dorsal crest is shown by the neural spines, but the chevron 

 bones were small and there is no indication of natatorial 

 power. 



The remains of this reptile are not uncommon in the Permo- 

 Carboniferous deposits but the bones are mostly isolated and 

 frequently water worn. It is believed that it lived upon higher 

 land some distance from the lagoons and pools in the deposits 

 of which the bones are found, and that the" partially destroyed 

 cadavers or isolated bones were transported to the place of 



