CHAPTER VI. 



A HISTORY OF THE CLASSIFICATION OF THE AMPHIBIA, WITH ESPECIAL 

 REFERENCE TO THE SPECIES FROM THE COAL MEASURES. 



It has been necessary, in the course of the present study, to review thoroughly 

 the classifications which have been proposed for the group. A classification of some 

 sort is necessary for the proper grouping of the species which have been recovered 

 from the Coal Measures deposits of this continent, and my reason for publishing 

 this relatively dry material is that the classifications formerly proposed (469), as 

 well as the one here given, may have a proper historical background. 



The review of the proposed systems of classification has been much facilitated 

 by the discovery, in the University of Chicago, of some notes by the late Dr. George 

 Baur on the ' ' Stegocephali. ' ' The notes were not discovered until after the literature 

 had been pretty thoroughly covered, and it was a source of some gratification, on 

 comparing notes with those of Dr. Baur, to find but few omissions. Whether Dr. 

 Baur had ever contemplated a work on the Stegocephala or not I have been unable 

 to learn, but it is certain that he carefully and laboriously went through the litera- 

 ture on the subject and copied by hand the classifications of each author from 1842 

 to 1895, together with other notes of interest on the structure, distribution, and 

 phylogeny, including many tracings. The classifications given below are taken, in 

 part, from his notes, although all references have been verified with the original 

 sources. 



The first attempt to combine in classification the knowledge of the extinct and 

 recent amphibians was made by Johannes Jacob von Tschudi in 1839 (574). Pre- 

 vious to that time Goldfuss (295) and von Meyer (418) had described various 

 species of salamanders and frogs from the Tertiary deposits of Switzerland, and 

 these Tschudi considered in his following classification: 



A. Ranse. B. Cceciliae. 



a. Hyla. a. Ccecilia. 



b. Cystignathi. C. Salamandrinae. 



c. Ranee. a. Pleiiroddes. 



d. Ceratophrydes. b. Salamandra. 

 c. Bombinatores. c. Tritones. 



f. Bufones. d. Tritonides. 



g. Pipae. D. Protoideas. 



Although the remains of Mastodonsaurus had been known and widely com- 

 mented on for several years before Tschudi proposed this scheme, he does not 

 include this genus in his classification of the Amphibia, for the reason that for 

 nearly a quarter of a century after the discovery of the labyrinthodonts they were 

 regarded as reptiles, even so eminent an authority as von Meyer (423) including 

 them in his "System der fossilen Sauricr." The view that the labyrinthodonts were 



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