2 AMPHIBIA AND PISCES OF THE PERMIAN OF NORTH AMERICA 



It is suggested here that Orthacanthus and Diplodus may be synonymous. 

 The two species Ceratodus gurleianus and C. paucicristatus are referred to a 

 new genus, Ptyanodus. 



In this same paper Cope remarks that he is informed that Professor 

 Bradley's layer No. 15 occupies a higher position than was assigned to it and 

 that it lies unconformably above the Merom sandstone, which lies above 

 the Coal Measures and is unconformable with them. This confirmed Cope 

 in his reference of the bone-bearing beds, his Clepsydrops shales, to the 

 Permian. As will be shown below, the position of these beds is still very 

 much in doubt. 



In 1878, in his first contribution to the history of Permian fauna of Texas 

 (23), Cope reported the following new amphibians: 



Epicordylus erythroliticus. Zatrachys serratus. 

 Eryops megacephalus. Trimerorhachis insignis. 



Parioxys ferricolus. Rachitomus valens. 



Epicordylus, which was founded on the caudal vertebrae oi Eryops, as later 

 recognized by Cope, was here regarded as a reptile. 



Parioxys was placed in the suborder Labyrinthodontia, and Trimerorhachis 

 and Rachitomus in the Ganocephala. Rachitomus was founded on vertebrae 

 of Eryops. Two humeri, without entepicondylar foramina, Nos. 5 and 6, are 

 referred to the Pelycosauria; these evidently belong to the genus Eryops. 



Three new dipnoans are named in the same paper, Ctenodus periprion, 

 C. porrectus, and C. dialophus. 



Cope here correlates his Clepsydrops shales of Illinois with the Texas beds 

 and reasserts the reference of both to the Permian. "The evidence now 

 adduced is sufficient to assign the formation, as represented in Illinois and 

 Texas, to the Permian. Besides the saurian genera above mentioned, the 

 existence of the icthyic genera Janassa, Ctenodus, and Diplodus, in both local- 

 ities, renders this necessary." 



In 1878, Marsh (60) described in the "American Journal of Science" some 

 fossils from New Mexico, naming as new Ophiacodon mirus and 0. grandis 

 from very fragmentary remains. They were regarded as reptiles, but are 

 clearly amphibians of uncertain relationships. 



In 1880, in the "American Naturalist" (24), Cope referred Eryops, 

 Rhachitomus, Trimerorhachis, and probably Actinodon of Gaudry, to the 

 Ganocephala, because they possessed distinct intercentra and centra, the 

 Labyrinthodontia having the vertebra solid. 



In a more extended paper before the American Philosophical Society, in 

 the same year (26), Cope reviewed Owen's suborder Ganocephala, and after 

 concluding that the definition was inadequate he offered a new definition of 

 the group, as follows : 



"Vertebrae consisting of centra and intercentra, the former not extend- 

 ing to the base of the vertebra, the latter not rising to the neural canal. The 

 centrum consisting of two parts distinct from the superior neural arch; viz, 

 a lateral piece (pleurocentrum), on each side. Atlas consisting of separate seg- 



