EDWARD D. COPE. 65 



the other subclasses in the presence of the maxillary 

 arch and the opercular apparatus. 



III. THE LINE OF THE BATKACHIA. 



We know Batrachia first in the coal measures. They 

 reach a great development in the Permian epoch, and 

 are represented by large species in the Triassic period. 

 From that time they diminish in numbers, and at the 

 present day form an insignificant part of the vertebrate 

 fauna of the earth. The history of their succession is 

 told by a table of classification, such as I give below : 



I. Supraoccipital, intercalary and supratemporal bones present. 



Propodial bones distinct. 

 Vertebral centra, including atlas, segmented, one set of segments to- 

 gether supporting one arch Rhachitomi. 1 



Vertebras segmented, the superior and inferior segments each complete, 



forming two centra to each arch Embolomeri. 



Vertebral centra, including atlas, not segmented, one to each arch 



Stegocephali. 



II. Supraoccipital and supratemporal bones wanting. Frontal and 



propodial bones distinct. 

 a. An os intercalare. 



A palatine arch and separate caudal vertebras Proteida. 



oca No os interclare. 

 A maxillary arch : palatine arch imperfect ; nasals, premaxillaries and 



caudal vertebras distinct Urodela.' 2 



No maxillary or palatine arches ; nasals and premaxillary, also caudal 

 vertebra?, distinct Tracliystomata. 



III. Supraoccipital, intercalare and supratemporal bones wanting. 

 Frontals and parietals connate ; propodial bones and caudal vertebras 

 confluent. 



Premaxillaries distinct from nasals ; no palatine arch ; astragalus and 

 calcaneum elongate, forming a distinct segment of the limb. .Anura. 



The probable phylogeny of these orders as imperfectly 

 indicated by paleontology is as follows : 



1 Includes the Eryopidte. 



2 Probably includes the Gyrnnophiona. 



49 



