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Show 1888.] THE CARPUS AND TARSUS OF THE ANURA. 151 Unterlage fiir den Fersenhbcker, der vielfacb als Grab-Instrument benutzt wird, zu gewinnen." W e have already called attention (p. 150) to the development of a retral process from that which we regard as the hallux-metatarsal. In Hyla lichenata this is completely segmented off (* in woodcut, fig. A ) , forming one of a series of marsrinal elements, The pre-hallux of opposite sides in Hyla lichenata. Dorsal aspect. X 6. which skirt the outer face of the calcar and are, moreover, roughly symmetrical on opposite sides. Comparison of this figure with that of the more normal pre-hallux of H. ccerulea (Plate VIII. fig. 19) renders it tolerably certain that these nodules are dismemberments of the main mass. It would be superfluous here to recapitulate the well-known speculations and discussions which turn on the supposed ancestral condition of the pentadactyle limb 1 ; it is more pertinent to point out that the evidence against the supposition that all living Amphibia and Amniota have directly inherited a pentadactyle member, is, to no inconsiderable extent, based upon the discovery of fragmentary cartilages in no way indistinguishable from these now under consideration. Such fragments have been discovered flanking both pre-and postaxial borders of the one member or the other in even Man himself2; and in the fertile imaginations of Bardeleben, Kehrer (24), and others, we find them exalted to the dignity of lost rays. The last-named author writes (p. 14) "so flatten wir also bei der Beurtheilung des Hand- und Fuss-skeletes der Wirbelthiere kiinf-tighin nicht mehr von einer pentadactylen, sondern von einer hepta-dactylen Urform auszugehen, und von diesem Gesichtspunkte aus 1 For details and resume see Gegenbaur (19), and Wiedersheim (36), pp. 204-207 and 229-230; also " Zur Urgesch. d. Gliedmassen d. Wirbelth,"' H u m boldt,' vol. 5, 1886. 2 Bardeleben, ' Jenaische Zeitschr. fiir Naturwiss.' Bd. 19, N.F. xii. Supplem.- Heft 3, 1886. Cf Wiedersheim, ' Lehrbuch,' p, 224, and ' Humboldt,' cit. |