douthitt: eryops; eryopsoides. 241 



other, either where two teeth are present or where there are fresh 

 scars. 



Considering that there is not an exception in all the skulls or 

 published drawings available, this character seems to indicate 

 that the New Mexican specimens are distinct from those from 

 Texas. No doubt, better-preserved material will show other im- 

 portant differences. If the materials described by Cope be of this 

 animal, then the New Mexican specimens have the apices of the 

 neural spines contracted, and differ in the character of the in- 

 tercentra. The skulls at hand from New Mexico seem to be 

 shorter and broader than tho^se from Texas, but owing to the 

 imperfection of the material this can not be proved. But until 

 better material is secured we must reh^ upon this one character, 

 which should be of generic rank. For the new genus the name 

 Eryopsoides is proposed, and specimen No. 826 of the Peabody 

 jMuseum is named as type. "Whether Alarsh's Ophiacodon graiidis 

 (1878) and Cope's Eryops reticulatus (1881) are the same species 

 will perhaps never be known, since the type materials are lost; 

 but since Marsh's name precedes, it should be adopted as the 

 specific name for the New ^Mexico specimens referred to Eryop- 

 soides. 



While there is no particular interest in the mere fact of recog- 

 nizing a closely allied but distinct genus, the recognition is in this 

 case of considerable interest, since it shows that Eryops is not 

 common to both regions. The faunae of these regions, so far as 

 known, have very little in common, Edaphosaurus and Diadectes 

 being now the only forms recognized as common to both. It is 

 not at all improbable that better-preserved specimens \^'ill show 

 that the New Mexico specimens referred to Diadectes are really 

 generically distinct, and that Edaphosmirus is the only genus com- 

 mon to both regions. This would indicate a faunal separation of 

 the two regions, and the nature of the animals is such as to show 

 that they developed parallel, rather than that they were separated 

 in time, and one descended from the other. 



BIBLIOGRAPHY. 

 Branson, E. B. 



1905. Structure and Relationship of the American Labyrinthodontidae. 



Journal Geology, Vol. 13, 568-610. 

 Broom, R. 



1913. On the Structure of the Mandible in the Stegocephalia. Anat. 



Anz., Bd. 45, 7-3-78. 



1913. Bulletin American Museum of Natural History. 



16— Sci. Bui. X. 



