1888.] THE CARPUS AND TARSUS OF THE ANURA. 173 



Attention has already been called by one of us ^ to the existence 

 of unexpected specific and even individual variations in the larynx 

 of certain Anura ; and we anticipate that a similar range will sooner 

 or later be demonstrated for those in the carpus of this family, if of 

 none other. 



The pollex consists, in all specimens with which we have dealt, 

 of one piece, irrespective of its carpal. In Phryniscus IcBvis this 

 structure recalls {po. ii. fig. 30), as does the ' hand ' generally, the 

 condition of the Common Frog. In Rhombophryne (fig. 32) it is 

 broad and calcariform. 



Hind Foot {fi^s. 31 & 33). 



In this we meet with variations little less surprising than 

 those of the fore foot. The astragalus and calcaneus are in Phry- 

 niscus Icevis widely separated (a., c, fig. 31) ; in P. cruciger and 

 P. varians they lie close together as in the Tree-Frogs. 



The hallux-tarsal is variable in the extreme in its relationships. 

 In Brachycephalus, Microhyla, and Rhombophryne (fig. 33 ') it is 

 distinct and of fair size ; in Phryniscus cruciger it had fused with the 

 naviculare ; while in the soUtary specimen of P. varians examined it 

 was confluent with the os cuboideum (tarsalia 2 and 3). 



The calcar consists, in its simplest condition {Brachycephalus, 

 Microhyla, Phryniscus varians, Rhinoderma, Rhombophryne, fig. 33) 

 of two elements. In Phryniscus cruciger these had anchylosed, but 

 in the young of P. IcBvis figured (fig. 31) four distinct elements were 

 discernible. 



It is worthy of remark that the anterior of the two ligaments 

 which we record for the Hylidas (p. 1(38, Plate VIII. fig. 19) re- 

 appears here with its contained sesamoid cartilage. 



ff. Dendrobatid^. 



One specimen of Dendrobates tinctorius was examined, but its 

 carpus and tarsus correspond so closely with those of the Frog that 

 it is needless to describe them separately. 



h. Ranid^. 

 Examined : — 



Rappia marmorata. 



Nannophrys ceyloniea. 

 lihacophorus maculatus ; R. eques. 

 Ixalus leucorhinus. 

 Cornufer vitianus. 

 Megalivalus madagascariensis. 

 Rana alticola ; R. cyanophlyctis ; R. arvalis. 

 Rana esculenta ; R. temporaria : a large series of specimens 

 at all stages. 



There is a marked constancy in the carpus and tarsus of this 



2 P.Z.S. 1887, pp. 491-501. 

 Proc. Zool. Soc— 1888, No. XIII. 13 



