PROBLEM OF THE AMPHIBIA FROM THE COAL MEASURES. 5 



and if their descendants continued on as reptiles, as has been suggested (469) , we 

 do not know the intermediate stages. 



The Aistopoda are without doubt specialized microsaurs, and, in the opinion 

 of the writer, are not entitled to separate rank. Some of these forms reached a 

 high degree of specialization. One American species has the skeleton reduced to a 

 long, slender head and a slender series of elongate vertebrae, all other parts of the 

 skeleton, even the ventral armature, being absent. The proportions attained by 

 this species, Phlegethontia linearis Cope, recall those of the coach-whip snake, 

 Zamenis flagellum Shaw, of the western plains. Some of the so-called Aistopoda 

 have been credited by Fritsch with the possession of peculiar clasping organs, 

 "Kammplatten." Newberry has written of the discovery of similar structures in 

 the Ohio Coal Measures (498), but the statement of the actual association of these 

 ' 'Kammplatten ' ' needs confirmation. Dr. R. H. Traquair wrote to the author under 

 date of April 28, 1909: 



"I maintain that the association of a bundle of 'Kammplatten' with a specimen of Ophi- 

 derpeton in the Bohemian gas coal was entirely accidental. Of such pitfalls the paleontolo- 

 gist has to beware or serious mistakes may be the consequence, as has happened more than 

 once. I must, however, publish a short paper on the Kammplatten, for I think I know 

 what they are now." 



Fritsch, however, has very clearly figured a nearly complete specimen of Ophi- 

 derpeton (251, Bd. iv) as possessing the Kammplatten in place near the cloaca, 

 where he suggests they may have served the function of accessory copulatory 

 organs or claspers. 



The Temnospondylia are represented by scanty remains of species from Illinois, 

 Pennsylvania, and Nova Scotia. The forms belonging to this group are all rela- 

 tively large, and they had a wide geographical distribution during the Permian. 

 This group contains two types of vertebras, known as the embolomerous and the 

 rachitomous, both of which are present in the Coal Measures. Such forms as 

 Eosa urns, Baphctes, Eobaphetes kansensis, Macrerpeton, and Dendrerpeton are regarded 

 tentatively as temnospondyles, but there is no definite assurance that they are such. 

 It is possible that Eosaums is a stereospondyle, but the species is too incompletely 

 known for a definite statement to be made. The close resemblance between the 

 vertebrae of Eosaurus and Anthracosaurus has been noted by Huxley (332). 



The Stereospondylia are very scantily represented in the Coal Measures, if at 

 all. Eosaurus may belong here as indicated above. The tooth and cranial frag- 

 ments discovered and described by Williston from the Coal Measures of Kansas 

 may represent a stereospondyle as he states (608), but the evidence is incomplete. 

 A fragment of a large rib (plate 22, fig. 4) of a species from Linton, Ohio, otherwise 

 unknown, may be a stereospondyle. We would expect an early development for 

 this group, but it is an interesting fact that no stereospondyles are known defi- 

 nitely before the Triassic, during which period they had an extensive distribution. 



