366 H. D. REED 



Various studies of the Cryptobranchidae contribute informa- 

 tion which is suggestive in its bearing upon the rank and kinship 

 of this group. Versluys ('09), in summarizing the structure of 

 the Cryptobranchidae, observes that they retain many features 

 of a larva, and, at the same time, acquire many of adult sala- 

 manders. Thus the skull is that of the adult, while the circula- 

 tory organs approximate those of the larva. Versluys concludes 

 with the statement that the Cryptobranchidae are to be looked 

 upon as partly transformed larvae and an offshoot of the ambly- 

 stomid stem. That they are arrested in transformation is the 

 conclusion of Bruner ('14), based upon a study of the respiratory 

 mechanism. Wiedersheim (77) and Drtiner ('01, '02) find that 

 both the skull and branchial apparatus of the Cryptobranchidae 

 bear striking resemblances to these structures in Raniceps and 

 Hynobius, which argues for an amblystomid alliance of this fam- 

 ily as shown by Wiedersheim in his phyletic arrangement of fam- 

 ilies. Herrick ('14), in a comparative study of the cerebellum 

 of urodeles, discovered some suggestive points which I interpret 

 as designating the Crjrptobranchidae an offshoot of the ambly- 

 stomid stem rather than the reverse of these conditions. In one 

 instance Herrick writes: ''The cerebellum of Cryptobranchus 

 occupies an intermediate position between those of Amphiuma 

 and Ambly stoma." The position given the Cryptobranchidae 

 in plate 6 is in accord with Herrick's observation. 



A review of the important features of morphology, develop- 

 ment, and distribution supports the view that the Cryptobranch- 

 idae are not primitive amphibians, but, as Smith ('12) has pointed 

 out in his conclusions, are terrestrial forms which have secondarily 

 become aquatic, in consequence of which certain larval features 

 are retained, although these forms advance far enough toward 

 their former state to actually begin transformation which is 

 arrested. The conclusions arrived at from a consideration of 

 the sound-transmitting apparatus are not in harmony with any 

 view which allies the Cryptobranchidae with any other than the 

 amblystomid group. 



The sound-transmitting apparatus of the amblystomid legion 

 seems to the mind of the present writer to echo the past history 



