The Smooth Facial Muscles of Aniira and 

 Salamandriua, 



a Coutributioii to the Auatomv and Physiology of the Respiratory 

 Mechanism of the Amphibians. 



By 



Heury L. Brunei', 



Ph. D. 



Butler College, Indianapolis, Indiana. 



With plates XVII and XVIII. 



Introduction. 



I have already published a brief notice (9) of the discovery in 

 certain Anura of rudimentary nasal muscles homologous with those 

 previously described by me in the Salamandrinai. My chief aim in 

 the following pages is to present a description of these muscles of the 

 Anura. In order to determine their homology, however, I have been 

 compelled to make a new and more exhaustive study of the nasal 

 region of the Salamandrina, as a result of which I am able to 

 supplement, in some respects, my previous description of the nasal 

 muscles of the latter group. Another result, also incidental to the 

 original inquiry, was the discovery in Anura of a muscle which 

 assists in closing the mouth. Since this muscle and the nasal muscles 

 above referred to, all belong to the respiratory mechanism, their 

 discovery leads to a review of the structure and function of those 

 parts of this mechanism which are concerned in opening and closing 

 the mouth and external uares. As an introduction to this description. 



1 Salamandrina = Myctodera. 



22* 



