68 REVISION OF THE PELYCOSAURIA. 



fections of the specimens make it impossible to settle the matter and until 

 the discoveries of Amalitzky in northern Russia are published it seems 

 unprofitable to enter into a lengthy discussion. The crucial test of the con- 

 dition of the arches can not be applied because the region is not preserved 

 in either specimen. The points that have been cited by authors to show 

 their relations to the Pclycosauria; the enlarged maxillary and incisor teeth 

 with crenate edges ; the high facial region formed by the maxillary in 

 large part ; and the curved alveolar edge of the jaws, are all points that are 

 common to the Pelycosauria, the Thcrocephalia and the Theriodcvitia ; indeed, 

 the wide maxillary causing an elevation of the facial region is a necessary 

 accompaniment of the enlarged canines with their enormous roots. 



Deuterosaiiriis has no enlarged external process on the pterygoid; 

 RJiopalodon has such a process {vide v. Huene). The vertebra of the two 

 are deeply amphicoelous but not perforate. Intercentra occur only in the 

 anterior portion of the vertebral column. They occur in connection with 

 Pareiasaurns, which is found with Theriodont remains, Inostranzevia anna; 

 Amalitzky in the deposits of the North Dwina river ; Paretasannis, even 

 the Pareiasauyidce, ai'e never found with the Pclycosauria. 



All these points lead to the conclusion that they are nearer to the Theri- 

 odont than the Pelycosaurian stem. Von Huene' s conclusion was that they 

 stood nearer to the Pelycosaurs than the Theriodonts, but were derived from 

 the beginning of the Pelycosaurian stem. 



Family EDAPHOSAURIDAE Cope. 



Proc. Am. Phil. Soc, vol. xx, 1882, p. 450. Also Pal. Bull. 35. 

 Proc. Am. Phil. Soc, vol. xx, 1883, p. 631. Also Pal. Bull. 36. 



Type: The genus Edaphosaurus described below. 



The family was first described as containing Pantylus and Edaphosaurus. 



Original description: "The two genera may be placed in a separate family of the 

 Pelycosaiiria, to be called the Edaphosauridu-. This family will be distinguished 

 from the ClepsydropidcB by the presence of more than one series of teeth on parts of 

 the jaws." 



In 1883 Cope added the structure of the temporal region to the descrip- 

 tion of the family. 



'■'•Pariotichiis, Pantylus, and probably Ectocynodon must be referred to a special 

 family, the Parioticliidce, which has teeth like the Edaphosauridce, but differs iu the 

 entire overroofing of the temporal fossae." 



In 1888 (70) Cope listed the genus Edaphosaurus in the family Clepsy- 

 dropida;^ abandoning the Edaphosauridce. 



