170 PROF. G. B. HOWES AND W. RIDEWOOD ON [Mar. 6, 



Born records (6, p. 55) individual variations in the constitution 

 of the pre-hallux ; we agree with him only so far as concerns the 

 presence of three segments irrespective of our tarsal one (c/. p. 149). 

 The terminal one of these is never recognizable in the adult (fig. 23), 

 and we have failed to find it in Pseudophnjne. 



e. CystignathidvE. 

 Examined : — 



5 Limnodynastes tasmaniensis ; L. dorsalis. 

 Leptodachjlus pentadaciylm ■■ 140 mm. 

 Leptodactylus albilabris : 23 mm. 

 Ceratophnjs ornata : 140 mm. 

 Ceratophrys americnna. 

 Chiroleptes australis. 

 Crinia varia. 



3 Pseudis paradoxa, tadpoles. 

 2 Eylodes martinicensis. 

 Telmatobius jelskii, tadpole. 

 Paludicola bibronii. 



4 Heleioporus albopunctatus. 



Fore Foot (figs. 2o, 26, and 28). 

 Gegenhaur (18) and Hofmann (21) have alluded casually to the 

 limb- skeleton of one or two genera of this family ; but the most 

 complete account yet published is that of Mayer (27). 



The skeleton of the fore foot resembles, in its general aspect, that 

 of the Frog ; and in a family where three of the eight carpal elements 

 are invariably fused together (capitato-hamatum, 3, 4 k) there is 

 little room for modification of any morphological importance. The 

 carpus of Limnodynnstes (fig. 28) may be conveniently taken as a 

 type of the whole family. The naviculare (w) lies well towards the 

 radius, being prolonged forwards into a tiiin edge. The poUex 

 carpal is free and httle modified, carrying the pollex (po. ii.). This 

 consists of a single element which is, in the male, shovel-shaped and 

 beset by a horny investment, much in the manner of the calcar in 

 Pelobates or Heleioporus. 



The following are the more important departures from the above 

 that we have observed in the genera recorded : — 



Pseudis (fig. 26). — The second digit is remarkable for its slender- 

 ness, while it is closely related to the pollex, and, with it, opposable. 

 This change is accompanied by a corresponding increase in calibre 

 of the head of the 3rd metacarpal (3'). The carpal of the pollex is 

 greatly elongated, in excess even of that which is seen in the Hylid<E. 



Ceratophrys. — The naviculare here lies in the proximal row, and 

 offers a broad surface for articulation with the radius. The carpal 

 of the pollex is stouter than that of the second digit, and it bears 

 two short, but well-defined and fully ossified, segments \ 



Leptodactylus. — The naviculare is here in full articulation with 



1 This is also the case in Paludicola. 



