HISTORICAL REVIEW 



The Rhachitovii are held to contain the Eryopida, and the Ganocephala 

 the Trimerorhachida and Archegosauridce. 



In May of 1886, Cope read before the American Philosophical Society a 

 catalogue of the Permian Vertebrates of North America (41). This was 

 published as a separate in the same year, but the volume of the Transactions 

 of the Society in which it appeared was not completed until 1888. In 

 this paper he gives the following list and arrangement of the fishes and 

 amphibians : 



Pisces. Batrachia. 



SELACHII. 



Thoracodus emydinus. 

 Janassa. 



J. strigilina. 



J. gurleiana. 



J. ordiana. 

 Orthacanthus. 



0. gracilis. 



0. quadriseriatus. 

 Didymodus. 



D. texensis. 



D. platypternus. 



DIPNOI. 



Ctenodus. 



C. fossatus. 



C. gurleianus. 



C. periprion. 



C. porrectus. 



C. vabasensis. 



C. dialophus. 



C. pusillus. 

 Ptyanodus. 



P. vinslovii. 



P. paucicristatus . 

 Gnathorhiza serrata. 

 Ceratodus favosus. 



TELEOSTOMI. 



Ectosteorhachis. 

 E. nitidus. 

 E. ciceronius. 



GANOCEPHALA. 



Trimerorhachis . 

 T. insignis. 

 T. bilobatus. 



RHACHITOMI. 



Zatrachys. 



Z. serratus. 



Z. apicalis. 

 Eryops. 



E. megacephalus. 



E. erythroliticus. 



E. ferricolus. 



E. reticulatMS. 

 Acheloma cumminsi. 

 Ansiodexis imbricarius. 



STEGOCEPHALI. 



Diplocaulus. 



D. salamandroides. 

 D. magnicornis. 



EMBOLOMERI. 



Cricotus. 



C. heteroclitus. 

 C. gibsoni. 

 C. crassidiscus . 

 C. hypantricus. 



