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

Dimensions.—Radius of the arms 0.2; breadth at the base 0.07, at the truncated end 0.2.

Habitat.—Pacific, central area, Station 274, surface.

Subgenus 2. Hymenastromma, Haeckel.

Definition.—Arms at the distal end provided with radial spines.

7. Hymeniastrum ternarium, Haeckel.

Histiastrum ternarium, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 76, Taf. xxiv. fig. 2.

Arms two and a half times as long as broad, three times as broad at the truncated end as at the narrow base, with a strong, conical, radial spine at the end. Patagium incomplete, enveloping only the basal half of the arms, with three to four convex chamber-rows.

Dimensions.—Radius of the arms (without terminal spine) 0.02; breadth at the base 0.025, at the broadest terminal part 0.08.

Habitat.—Fossil in the rocks of Barbados.

8. Hymeniastrum trigonarium, n. sp.