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Show 1888.] THE CARPUS AND TARSUS OF THE ANURA. 173 Attention has already been called by one of us2 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 laivis 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 (figs. 31 & 33). In this we meet with variations little less surprising than those of the fore foot. The astragalus and calcaneus are in Phryniscus 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 solitary 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. lavis 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 Hylidte (p. 168, Plate VIII. fig. 19) reappears here with its contained sesamoid cartilage. g. DENDROBATID^E. 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-E. Examined :- Rappia marmorata. Nannophrys ceylonica. Rhacophorus maculatus ; R. eques. Ixalus leucorhinus. Cornufer vitianus. Megalixalus madag ascariensis. Rana alticola ; R. cyanophlyclis; 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 |