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Show 176 PROF. G. B.HOWES AND W. RIDEWOOD ON [Mar. 6, becomes modified preaxially in connection with the thumb-pad. W e have nothing to add to Leydig's account of this feature (20). The heads of the 2nd, 3rd, and 4th metacarpals are expanded and more or less considerably excavated, for articulation upon the carpaha and the capitato-hamatum. The head of the 5th metacarpal is, like its shaft, comparatively verv slender, while it is so modified as to embrace the postero-external angle of the capitato-hamatum in the manner of a pincers apparatus. Hind Foot (Rana temporaria). The astragalus and calcaneus (a., c.) are much elongated, confluent at their extremities, concave internally, and either circular or elliptical in section. Their internal borders bound the limits of origin of the adductor longus digiti primi muscle, the tendon of which (m.a.l.) Fig. C. Hana temporaria, $, 54 m m . in length. Left hind foot, dorsal view, x 12. m.a.l. tendon of the adductor longus digiti primi muscle. Other references as at p. 182. is inserted into the naviculare («'). With the full development there arises from the epipbysial cartilage of the astragalus a prominence which overlies the tendon', and which ossifies with age; in old individuals there passes between it and the calcaneus an annular ligament. Tarsalia 4 and 5.-Represented in ligament, which is not recognizable in adult specimens. Tarsalia 2 and 3.-Invariably united to form the splint-like 1 Cf. Ecker (17, p. 128, and fig. 91). |