Page:Scientific results HMS Challenger vol 18 part 1.djvu/252

44 the capsule one single very large spiculum, whilst the others are much smaller (fig. 3). All the alveolated capsules are placed in one single stratum on the surface of the jelly-like spherical cœnobium, comparable to the blastoderm-cells of a blastula.

Dimensions.—Diameter of the central capsules 0.08 to 0.1, of the alveoles 0.2 to 0.4, length of the spicula 0.1 to 0.3.

Habitat.—South Pacific (Juan Fernandez), Station 300, surface.

12. Sphærozoum verticillatum, n. sp. (Pl. 4, fig. 7).

Spicula all geminate-triradiate, with a short simple middle rod and three much longer arborescent shanks on each end of it. Shanks straight, slender, pine-shaped, each in the distal half with three to four elegant verticils of thorny lateral branches.

Dimensions.—Diameter of the capsules 0.1 to 0.12, middle rod of the spicula 0.03 to 0.05, shanks 0.1 to 0.15.

Habitat.—Indian Ocean, Ceylon, Haeckel; Madagascar, Rabbe; surface.

13. Sphærozoum octoceras, n. sp.

Spicula all geminate-quadriradiate, with a short simple middle rod and four diverging shanks on each end of it. Shanks smooth, irregularly curved or bent, three to six times as long as the middle rod. It may be regarded as the social form of Thalassoxanthium octoceras (Pl. 2, fig. 6).

Dimensions.—Diameter of the capsules 0.12 to 0.16, middle rod of the spicula 0.02, shanks 0.01.

Habitat.—Australia, south coast, Faber; Station 163, surface.

14. Sphærozoum quadrigeminum, n. sp.

Spicula all geminate-quadriradiate, with a long thick middle rod and four shorter diverging shanks on each end of it. Shanks straight, thorny.

Dimensions.—Diameter of the capsules 0.06 to 0.08, length of the spicula 0.05 to 0.15.

Habitat.—North Atlantic, Azores, Station 354, surface.

15. Sphærozoum araucaria, n. sp.

Spicula all geminate-quadriradiate, with stout straight middle rod and four longer diverging shanks on each end of it. Shanks arborescent, with six to twelve thorny lateral branches.

Dimensions.—Diameter of the capsules 0.1 to 0.15, length of the spicula 0.05 to 0.1.

Habitat.—South Atlantic, coast of Brazil, Rabbe; surface.

16. Sphærozoum arborescens, n. sp. (Pl. 4, fig. 8).

Spicula all geminate-quadriradiate, with a stout straight middle rod and four longer diverging shanks on each end of it. Shanks arborescent, pine-shaped, with four to six verticils of lateral branches, which again are ramified and thorny.