482 DB. W. G. EIDEWOOD ON THE LARVAL HTOBRA]SrCHIAL 



in the size of the space at the side of the copula, which is large 

 in Pseudis (fig. 5, s) but extremely small in Chiroleptes (fig. 7). 

 The copula itself is longer in Pseudis, and the pars reuniens is 

 broader. Owing probably to the shortness of the copula in 

 Chiroleptes, the hypobranchial symphysis is much longer in this 

 genus than in Pseudis. The fourth pair of spicula are normal 

 in the former, but are greatly expanded and fused with the third 

 pair in Pseudis ; a feature already alluded to and figured by Parker 

 (8. p. 73, pi. 10. fig. 6, and pi. 11. fig. 4, c. hr. 3-4), although in 

 his figures the shape of the parts is not quite correct. In the 

 earlier figure by Cuvier (2. pi. xxiv. fig. 22) this point is not 

 .evident. 



Parker has also figured (§. pi. 17. fig. 4) the hyobranchial 

 skeleton of a tadpole which, with some reserve, he identifies as 

 Cystignathus. The figure, however, calls for no special comment. 

 Two other genera of the Cystiguathidge were also examined by 

 this author, and in both {Calyptocephalus Gayi, 8. pi. 22. fig. 5, 

 and Cyclorhamphus culeus, pi. 22. fig. 9) a double basibranchial 

 described and figured. Seeing how important from a morpho- 

 logical point of view the occurrence of two successive basi- 

 branehials would be, it is somewhat surprising that the author 

 did not lay more stress upon the observation. Now the Cyclo- 

 rhamphus culeus examined by Parker is a Telmatohius (probably 

 Telmatohius JelsMi, see 1. p. 191); and since the double copula 

 does not occur in the T. marmoratus examined by me, a shadow 

 of suspicion naturally arises. To submit the matter to the final 

 test, I applied to Prof. Lataste for permission to examine one of 

 the tadpoles of Galyptocephalus Gayi from Chili, belonging to his 

 private collection, and he most graciously responded. There is 

 in Prof. Lataste's specimen no trace of a second copula behind 

 the pars reuniens, but the whole hyobranchial skeleton is per- 

 fectly normal, and occupies a position midway between those of 

 Chiroleptes and Pseudis in the proportions of the pars reuniens, 

 copula, lateral spaces, and fourth spicula. It is evident, there- 

 fore, that no great weight can be attached to this observation of 

 Parker's. 



BUEONID^. 



The hyobranchial skeleton of Bufo does not difier greatly from 

 that of Bana. The anterior edge of the hypobranchial cartilage 

 is more oblique, and a different shape is in consequence given to 



