1891.] 



TADPOLES OF THE EUROPEAN BATRACHIANS, 



595 



Biscoglossida, however, each ridge, or at auy rate the second, bears 

 two or even three rows of teeth (fig. 1, B). 



The history of the accessions to our knowledge of the structure of 

 the beak and lips has been given very fully by Heron Royer and 

 Van Bambeke. In addition to the works "of Schulze, Keiffer, and 



Fig. 1. 



B 



Open mouth of, A, Pelodytes punetatus, B, Alytes obstetricans. 

 b.o, buccal orifice ; l.p, labial papillse ; m, mandibles ; t, series of labial teeth. 



Gutzeit, mentioned above, I would refer tlie reader particularly to 

 the following papers : — 



C. Van Bambeke. " Recherches sur la structure de la bouche 



chez les tetards des Batraciens anoures." Bull. Ac. Belg. (2) 



xvi. 1863, p. 339, pis. i., ii. 

 F. E. ScHTJLZE. "Ueber Cuticulare Bildungen und Verhornung 



von Epithelzellen bei den Wirbelthieren." Arch. f. mikr. 



Anat. V. 1869, p. 295, pi. xvii. 

 H£ron Royer and C. Van Bambeke. " Sur les Caracteres 



