26 



MISS J. B. PROCTER ON THE SKULL AND 



111 later life (text-fig. 2 e) the cranial characters of li. adspersa 

 become more pronounced, the whole skull broadening and assum- 

 ing a more convex and massive form, and the slight rugosities of 

 the halfgrown becoming marked excrescences in old specimens. 



Although, therefoi-e, these two species dififer so widely in the 

 adult state, especially in external characters (such as general 

 shape, glandular folds, metatarsal tubercle, etc.), they bear 

 important fixed characters in common, which isolate them com- 

 pletely from all other species of the genus Rana. The subgenus 

 Auhria Blgr. might therefore be united with the subgenus Fyxi- 

 eephalus Tsch. In this I find that I am not much at variance 



Text-figure 1. 



Skull of Eana svhsigillata. (Nat. size.) 



a. Dorsal view. 

 h. Ventral view. 



c. Lateral view. 



d. Hyoid. 



with Mr. Boulenger, who has kindly allowed me to quote the 

 following remarks from his unpublished monograph on the Frogs 

 of Africa : — " Although I am at a loss to guess on what grounds 

 Giinther (Cat, Bat. Sal. p. 7) reached the conclusion, from the 

 original description of Aug. Dumeril, that R. snhsigillata appears 

 to belong to the genus Tomofterna {=■ Pyxicephalus), it is un- 

 doubtedly a fact that, in spite of its very different appearance, it 

 is more nearly allied to R. adsjjersa (the type of Pyxicephalus) 

 than to any other, as the cranial characters show." 



After reviewing the cranial and other characters of these two 



