Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, First Part: Porulosa (Spumellaria and Acantharia) / Report on the Scientific Results of the Voyage of H.M.S. Challenger During the Years 1873-76, Vol. XVIII

by Ernst Haeckel

Habitat.—Pacific, central area, Station 268, depth 2900 fathoms.

Subgenus 2. Heliostylus, Haeckel, 1881, Prodromus, p. 457.

Definition.—Margin of the disk with a solid equatorial girdle or a corona of radial spines.

3. Sethostylus dentatus, n. sp. (Pl. [34], fig. 1).

Heliostylus dentatus, Haeckel, 1881, Prodromus et Atlas (pl. xxxiv. fig. 1).

Disk with smooth surface, six times as broad as the medullary shell. Pores regular, circular; eighteen to twenty on the radius of the disk. Margin of the disk with a broad solid equatorial girdle, which bears fifty to sixty strong conical teeth on the periphery; teeth about as long as the diameter of the medullary shell. Both opposite marginal spines cylindro-conical, about as long as the diameter of the disk, and as broad as the girdle.

Dimensions.—Diameter of the disk 0.3, of the medullary shell 0.05; length of both main spines 0.2 to 0.3, breadth 0.02.

Habitat.—Pacific, central area, Station 272, depth 2600 fathoms.

4. Sethostylus serratus, n. sp. (Pl. [34], fig. 2).

Heliostylus serratus, Haeckel, 1881, Prodromus et Atlas (pl. xxxiv. fig. 2).