144 



REVISION OF THE PELYCOSAURIA. 



procoracoid-scapiilar suture is hardly traceable. The coracoid foramen and the one 

 on the shaft are both present and in the same position as in Dinictrodon; they open 

 into a similar crescentic cavity on the inner side. Another specimen, No. 4138 Am. 

 Mus., has the distal end complete, but lacks the anterior portion. 



The clavicle is unknown (see Naosaurus microdits No. 4060 Am. Mus.). 



The interclavicle is represented by a nearly perfect specimen, No. 4103 Am. Mus., 

 preserved with two imperfect scapulse. This specimen was described by Cope as 

 belonging to the genus Diiiietrodon, and his description is quoted in the discussion 

 of that genus. The shape is very similar to that of the intercentrum of Dimctrodon^ 

 but the scapuke accompanj-ing it show that it belongs to the genus Naosaurus. It is 

 larger and stronger than the interclavicle of Ditiietrodoii. 



The /ore limb is unknown. 



Fig. 65a. — Alternative restoration ot Edaphosaurus {Naosaurus). Compare plate 35. The animal is here represented 

 with the skull o( Edaphosaurus instead of a skull modeled on that of Dimetrodon. X about yi. 



The pelvis is represented by the badly broken and imperfect right half and the 

 nearly perfect left half (plate 31, fig. i). The only parts lacking are a distal border 

 of the ischium, which is attached to the fragment of the right side, and the distal end 



of the pubis. 



The ilium takes a large part in the acetabulum, but the sutures are not clearly 

 traceable. The crest rises almost vertically abo\e the acetabulum and is widely flared 

 at the distal end. There are no distinct facets on the inner side for the sacral ribs, but 

 a series of strong rugose lines. 



The ischium expands toward the distal end, so that the termination is high and 

 wide, very different from the ischium of Dimetrodon. 



