492 PROF. G. B. HOWKS ON AN UNRECOGNIZKD FEATURE [JunC 7, 



median procricoid (interarytenoid) elements in the Amphibia — an 

 interesting feature of comparison with the higher types. 



The Amphibian larynx is, like that of Reptiles, chiefly remarkable 

 for the absence of a distinct thyroid cartilage ; but the above resume 

 shows that with this exception there are represented in the respi- 

 ratory organs of the Amphibia, as a group, the leading constituents 

 of those of the higher Amniota. The epiglottis would, however, 

 appear to be absent ; and it is the object of this paper to inquire how 

 far this is really the case. 



It is necessary to point out that Henle wrote ^ of ' Engy stoma ^ 

 that " die Cunstrictoren des Stimmladeneingangs sind bei diesen 

 Species nur sehr lose an die Stimmlade befestigt, sie hegen in einer 

 Querfalte der Schleimhant hinter der Zunge und dem Eingang der 

 Stimmlade, und diese Falte bedeckt, wie eine Epiglottis, der vorder- 

 sten Theil des Eiiigangs der Stimmlade." 



My attention was first drawn to this subject two years ago, while 

 dissecting a male of the Grass-Frog {R. tempoi-aria). In that speci- 

 men (fig. la)' the front wall of the larynx was prolonged forwards 



Fig. 1. 



The larynx in Bana. 1. E. esculenta, young c?. 1 a. E. temjioraria,_ J. 

 1 b. E. tcmporaria, $ . \c. E. tcmporaria, ? . All magnified three times. 



eg, epiglottis ; l.a, aditus laryngis. 



into two papillate folds {eg.), which were tumid and connected 

 together by a thin film, the whole constituting a forward prolongation 

 of the laryngeal mucous membrane apparently superadded to that 

 which is customary. Wiedersheim, in describing the larynx of 

 R. esculenta, points out ^ that it hes immediately behind a deep 

 depression of the mucous membrane which corresponds with the 



' L. c. p. 28. 

 Originally figured in ' Atlas of Elem. Biology,' pi. i. Cg. 13 (1885). 

 'DieAnatomie des FroscLes,' Ecker and Wiedersheim, pt. 3, p. 8 (Brunswick, 

 1882). 



