1882.] 4bl [Cope. 



the Permian of the United States.* It is not improbable that such occur- 

 rence of genera may yet be substantiated, but the identification of an or- 

 der hitherto unknown in a formation, on uncertain characters, is not a safe 

 proceeding. The vertebra? of Leptophr actus although not certainly known, 

 are supposed to be of the Labyrinthodont type. The teeth are much more 

 compressed and trenchant than in the present species, nor do there appear 

 to be any long ones near the symphysis mandibuli. I consider the ques- 

 tion of reference to Leptophractus to be still an open one. 



The family Eryopidm, though abundant in individuals, is not represented 

 by many species. They are presumably as follows : 



Anisodexis imbricarius Cope. 



Acheloma cumminsi Cope. 



Eryops reticulatus Cope. 



Eryops ferricolus Cope (Parioxys olim). 



Eryops megacephalus Cope. 



Actinodon frossardi Gaudry. 



Zatrachys serratus Cope. 



Zatrachys apicalis Cope. 



But the occipital condyles are unknown in Acheloma and Zatrachys. 



I may add here that through the courtesy of Messrs. Scott and Osborne, 

 I have seen, in the Museum of Princeton College, vertebrae of some species 

 of the Rhachitomi from Saarbriicken, along with Archegosaurus, with entire 

 centra, from the same locality. 



Synopsis of the Vertebrata of the Paerco Eocene epoch. By E. D. Cope. 



(Bead before the American Philosophical Society, October SO, 1882.) 



REPTILIA. 



CROCODILIA. 



Crocodilus sp. 

 Grocodilus sp. 

 Crocodilus sp. 



TESTUDINATA. 



Plastomenus ? communis Cope. 

 Dermatemys sp. 

 Gompsemys sp. 

 Emys sp. 



* Peplorhina arctata Cope, from the Illinois Permian is not a Pepl'orhina, but 

 a Theroniorpli Saurian. 



