SKELETON AND LAKTNX OF XENOPTJS AND PIPA. 69 



and tlie first figures are those of Schneider (37. Tab. 2. figs. 4, 

 7-11). The specimen figured, a male, was in a bad state o£ 

 preservation, and this it was in all probability which led 

 Schneider into the mistake of regarding the larynx as a con- 

 stituent of the sternal skeleton (37. pp. 261 and 263). The 

 larynx of Pipa was first described in any detail by Breyer (4), 

 who gives figures, rather poor, of both sexes. A much better 

 description, referring principally to the male larynx, was 

 furnished in 1825 by Mayer (25), but without figures. In his 

 paper on Xenopus, ten years later, he gives a figure (26. Taf. 3. 

 fig. 5) of the larynx of the male Plpa, broken open to show 

 ihe elongated arytenoids lying within. The first figures show- 

 ing the detailed structure of the larynx we owe therefore to 

 Schneider and Mayer, and not to Henle as stated by Grronberg 

 (18. p. 634), who appears not to have seen the ' Historia am- 

 phibiorum' nor Mayer's second contribution. Much valuable 

 information is to be gathered from Henle's careful description 

 and illustrations of the larynx of both sexes. The study of the 

 larynx of Pipa was again undertaken by Grronberg in 1894, and 

 the eight figures that he gives (18. Taf. 38. figs. 10-17) are 

 excellent. He treats of both sexes, but chiefly of the male. 



I'emale. 

 The larynx of the female Pii^a is smaller in proportion to the 

 size of the whole hyobranchial skeleton than in the Xenopus 

 female. It is also relatively shorter in an antero-posterior 

 direction, but the length increases with age. The only ossified 

 parts are the thyrohyals (PL 9. fig. 1, t), which are very much 

 shorter, broader, and flatter than in Xejtopus, aud are situated in 

 the floor of the larynx and not at the sides. Their anterior ends 

 are nearly in contact, and the posterior epiphyses are indis- 

 tinguishably fused with the postero-ventral band of the cricoid 

 cartilage. The space between the bones themselves is closed by 

 membrane, a fact which Grronberg in his excellent paper fails to 

 notice, although Meckel (28. Theil vi. p. 451) and Henle (19. 

 p. 19, and Taf. 2. fig. 11. *.) had already pointed it out. Breyer 

 states that the ossified bars are absent in the young female. 

 His figure (4. Tab. 2, fig. 5) of the adult female larynx he 

 subscribes " Larynx f emina a parte inferiore cum laminis osseis," 

 but he most unfortunately locates the bones on the roof of the 

 larynx in his text (p. 15), " lamina inferior mere cartilaginea estj 



