OCR Text |
Show 1878.J A N D DISTRIBUTION O F T H E CRAYFISHES. 757 Fig. 1. Astacus fluviatilis. I. The outer face of the podobranchia of the antepenultimate thoracic limb of the left side ( X 4 ) : B, the basal portion ; st, the stem ; I, the lamina; br, the branchial filaments ; ap, the apical plume. II. The inner face of the same podobranchia ( X 4 ) : the letters as before, except g, the decurrent fringe, continued from the inner lobe of the lamina. III. A transverse section of the podobranchia, taken a little above the level of b in II. (X 4 ) : a, the inner lobe of the lamina ; b, its outer lobe ; st, the stem ; br, the branchial filaments. IV. One of the hooks of the lamina; and V The extremity of one of the seta3 of the base of the podobranchia : the vertical line indicates the scale to which these figures are drawn, and represents s-f w of an inch. VI. The coxopoditic seta? of the same limb (X 4). VII. The free end of one of these seta:, magnified to the same degree as IV. and V. PROC. ZOOL. S O C - 1878, No. L. 50 |