PLATE V.

Fig. 11.-Leucandra valida; gastral quadriradiate spicule; X 136.

Fig. 11a, Gastral triradiate spicule; X 136.

Fig. 11b. Subgastral triradiate spicule; X 136.

Figs. 11c, 11d. Dermal triradiate spicules; X 136.

Fig. 11e. Dermal oxeote spicule; X 136.

Fig. 12.-Leucandra Cumberlandensis (page 34). Twice the natural size. Fig. 12a. Part of a horizontal section; X 60.

Fig. 12b. Gastral quadriradiate spicule; X 136.

Fig. 12c, Subgastral triradiate spicule; × 136.

Fig. 12d. Triradiate spicule of the parenchyma; 136.

Figs. 12e, 12f. Quadriradiate spicules of the parenchyma; X 136.
Fig. 129. Large dermal triradiate spicule; X 136.

Fig. 12h. Small dermal triradiate spicule; X 136.

Fig. 12. Dermal oxeote spicule; X 136.

Fig. 12j. Linear spicule; X 136.

PLATE VI.

Fig. 13.-Heteropia Rodgeri (page 35). Twice the natural size.

Fig. 13a. Part of a horizontal section; × 136. The dermal oxea parallel to the long axis of the sponge are shewn in transverse section.

Fig. 136. Gastral quadriradiate spicule; × 272.

Figs. 13c, 13d. Gastral triradiate spicules; × 272.

Fig. 13e. Subgastral triradiate spicule; × 272.

Fig. 13f. Subdermal triradiate spicule; × 272.
Fig. 13g. Dermal oxeote spicule; X 136.

Fig. 14.-Grantia invenusta (page 32). Twice the natural size.
Fig. 14a. Part of a horizontal section; X 136.
Fig. 14b. Gastral quadriradiate spicule; × 272.
Fig. 14c. Gastral triradiate spicule; × 272.
Fig. 14d. Tubar triradiate spicule; X 272.

Figs. 14e, 14f. Dermal triradiate spicules; X 272.