THE SOUND-TRANSMITTINa APPAEATUS OF 

 SALAMANDEES AND THE PHYLOGENY 

 OF THE CAUDATA 



E. E. DUOT 

 Smith College 



Eesearches by Kingsbury and Eeed, extending througb 

 a number of years, have shown that the sound-trans- 

 mitting apparatus of salamanders consists of two ele- 

 ments. These are the columella and the operculum. 



In the most recent paper on this subject, Eeed (1920) 

 gives a resume of all the previous work, an extensive ac- 

 count of the state of affairs in the PletJiodontidce, a brief 

 account of the conditions in other forms, and the findings 

 are presented in the form of a family tree. 



The purpose of the present article is to add an account 

 of the condition of the apparatus in two forms not seen 

 by Reed, to question the condition described by Kings- 

 bury and Eeed for Dicamptodon ensatus {Amhystoma 

 teix'hrosum Auct.), to suggest a somewhat different inter- 

 pretation of the facts observed by them, and to propose 

 a somewhat different phylogeny, which seems to agree 

 quite as well with the otic apparatus and far better with 

 other anatomical features. 



Kingsbury and Reed (1909) were unable to examine 

 any of the Asiatic forms related to Hynohms. These 

 forms, as Cope pointed out long ago, are rather different 

 from the Ainhijstomidcs, with which they have usually 

 been associated, and should in fact form a family Hy- 

 nohiidcc. 



I have recently been able to examine large series of 

 Hi/nohius leechii from Korea. This animal shows a con- 

 dition of the otic apparatus different from any seen by 

 Kingsbury and Eeed, and a condition which I am com- 

 pelled to consider primitive. Both columella and oper- 

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