316 



THE AMERICAN NATUBALIST 



[Vol. LI 



Dr. Moodie's history of the classification of the Amphibia ap- 

 pears to the reviewer to be rather meager, since he simply lists 

 the classifications of his predecessors without giving any critical 

 ilisciission. It is surprising that in this chapter he did not men- 

 tion t!ie work of Fritsch with which he must be extremely famil- 

 iiir. Fritsch 's classification of the extinct Amphibia, although it 

 was adapted and extended from the classification proposed by the 

 British Association Committee in 1870, was, in the judgment of 

 the reviewer, a distinct contribution to the subject which cer- 

 tainly deserves notice in an historical review, especially since 

 Fritsch erected several new families and gave definitions of all 

 the European groups. 



The author's own classification is an interesting attempt to 

 divide the Amphibia of the Coal Measures into two major series 

 or subclasses, the first (Euamphibia) including all those which 

 may be related to modern types ; the second comprising all the 

 wholly extinct groups (microsaurs, aistopods and labyrintho- 

 donts of all suborders). He derives most of the modern urodeles 

 (Caudata) from the branchiosaurs, for which he has given con- 

 siderable evidence; he follows Cope in provisionally deriving 

 the modern Proteida from the Coccytinidae of the Coal Measures. 

 He regards the strange Diplocaulus, an amphibian with a head 

 like a colonial cocked hat, as a member of the Euamphibia, prob- 

 ably because its vertebrae bear short, straight, double-headed ribs 

 which are attached to paired lateral apophyses springing from 

 the middle of the vertebra, after the fashion of those of branchio- 

 saurs and Caudata and quite unlike the hour-glass centra of 

 microsaurs, which bear long, slender ribs between the vertebrae. 

 But Watson and Williston regard Diplocaulus and Brachyder- 

 pefon as microsaurs, the last named genus showing in the ver- 

 tebrae and in the skull how the Diplocauhis type may have been 

 derived from primitive microsaurian conditions. Indeed it may 

 well be argued that the branchiosaurs and urodeles (Caudata) 

 themselves, in spite of the retention of gills in the young, may 

 have been derived from primitive mierosnnrs. that is that the 

 vertebrae and ribs of micros;iur'< ;iri' on the whole much more 

 primitive than those of braiicliios;nifs and CaiKhita. 



The systematic rehitions and ori-in of t}i,^ froirs and toads re- 

 main (lonlitful. Dr. Mno.iie <_nvr< an exe,.Il,.nf dis.M.ssion of the 

 ivs.'inblanees of hi>in Wyiiian. from the Linton. Ohio, 



Coal Measures, to the modern Aniira but leaves tlie pli ylogenetie 

 problem open. Pelion is so little known that it may or not be 



