Figure 1 in Development and variation of the anuran webbed feet (Amphibia, Anura)

Figure 1. External hind limb morphology in anuran larvae. A–E, larval stage 31, a preaxial constriction delimits the distal autopodium; F–J, larval stage 36, digit differentiation is advanced; K–O, larval stage 40. A, Bombina variegata: the autopodium is almost cylindrical with an incipient postaxial elongation (the primary axis). B, Xenopus laevis and C, Pseudis paradoxa: the autopodium is almost cylindrical without an evident distal tip denoting digit IV. D, Phyllomedusa sauvagii and E, Elachistocleis bicolor: the pointed autopodium is clearly defined by the elongation of primary axis. F, B. variegata: elongation of digit IV is scarcely noticeable, and interdigital membranes are shorter than the digits. G, X. laevis and H, P. paradoxa: the autopodium is paddle-like, and interdigital tissues, which are extended up to digit tips, separate digits. Digits V, IV and III show similar degrees of growth. I, Phyllomedusa sauvagii and J, E. bicolor: digit differentiation progresses as outgrowths in the proximo-distal direction and elongation of digit IV is more extensive than that of the other digits. Interdigital membranes are absent. K, B. variegata: well-developed interdigital membrane and the elongated digit IV become defined before metamorphosis. L, X. laevis and M, P. paradoxa: later stages display extensive interdigital membranes reaching to the toe tips, with digits V and III as long as digit IV. M, Phyllomedusa sauvagii and O, E. bicolor: digits are completely free. Scale bar = 1 mm.