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Show 492 PROF. G. B. HOWES ON AN UNRECOGNIZED FEATURE [June 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 respiratory 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 wrote1 of 'Engystoma' that " die Constrictoren des Stimmladeneingangs sind bei diesen Species nur sehr lose an die Stimmlade befestigt, sie liegen 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 Eingangs der Stimmlade." M y attention was first drawn to this subject two years ago, while dissecting a male of the Grass-Frog (R. temporaria). In that specimen (fig. la)2 the front wall of the larynx was prolonged forwards Fig. 1. The larynx in Eana. 1. E. esculenta, young 3- 1 a- R. temporaria, 3- 1 b. E. temporaria, $. 1 c. E. temporaria, _j>. All magnified three times. ey, 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 out3 that it lies immediately behind a deep depression of the mucous membrane which corresponds with the [ L. c. p. 28. Originally figured in ' Atlas of Elem. Biology,' pl. i. fig. 13 (1885). 'Die Anatomie des Frosches,' Ecker and Wiedersheim, pt. 3, p. 8 (Brunswick, 1882). |