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.—Diameter of the disk 0.18, of the outer medullary shell 0.06, of the inner 0.023; length of the radial spines 0.09, basal breadth 0.03.

Habitat.—Indian Ocean, Ceylon, Haeckel, surface.

8. Astrosestrum floscula, n. sp.

Disk with smooth surface, two and a half times as broad as the outer and five times as broad as the inner medullary shell. Pores irregular, roundish; ten to eleven on the radius. Eight marginal spines triangular, plain, scarcely half as long as the radius of the disk, nearly as broad at the base, connected by an even equatorial girdle.

Dimensions.—Diameter of the disk 0.2, of the outer medullary shell 0.08, of the inner 0.04; length of the radial spines 0.09, basal breadth 0.07.

Habitat.—South Atlantic, Station 325, surface.

Subfamily 3. Heliodiscida, Haeckel, 1881, Prodromus, p. 457.

Definition.—Phacodiscida with a variable number of radial spines on the margin of the disk (ten to twenty or more), which are commonly more or less irregular (sometimes regularly formed and disposed).

Genus 193. Heliodiscus,[^[232]] Haeckel, 1862, Monogr. d. Radiol., p. 436.

Definition.—Phacodiscida with simple medullary shell and with numerous (ten to twenty or more) simple radial spines on the margin of the disk (commonly with a variable number and an irregular disposition of the undivided spines).