Report on the zoological collections made in the Indo-Pacific Ocean ...

660 EXPLANATION OP THE PLATES.Fig. B. Pectinura iufernalis, showing the disk and the variations ofthe " naked plates," x 3.C. OiMopinax stellatus, showing the arrangement of the radialand interradial plates on the disk, x 2.Plate IX.Pig. A.Cucumaria semperi.B. ColocMrus tuberculosus. Spicules seen from the side andfrom below.C. Actinocucumis difftcilis.D. Tliyone oheni. Calcareous ring and oesophagus.E. a and b, spicules of Stereoderma validum; c, c?, the same,seen a little out of focus; e^ a smaller spicule ; /, a spiculeseen in side view.P. Phyllophorus proteus. F'. Parts of calcareous ring.G. Holotliuria macleart.All but figs. D and F' are magnified 220 times, and are figures ofspicules; D is magnified f,F' twice.Plate X.Fig. A. Antedon carpenteri, nat. size. A a, A 5, A c. First, second,and typical pinnules, x 3.B. pumila, X 3. B a, B h. First and fourth pinnules,X3.C. loveni, nat. size. Ca,Ch,Cc. First, third, and typicalpinnules, x 3. C d, C e. Dorsal surface of arms in regionsmarked x and y in C, x 3.Plate XI.Fig. A. Antedon bidens, X 2. A a. A cirrus, X 4, Ab, Ac. Firstand third pinnules, x 4.B. deci2nens, x f.B a. Arm-joints from above, x 4.