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; diameter of each of the five circular disks 0.01; length of the square side 0.35.

Habitat.—West Indies, Cuba, surface (Thomson).

Subgenus 2. Spongastromma, Haeckel.

Definition.—Cross formed by the four arms bilateral or irregular, with the arms at different distances.

5. Spongaster orthogonus, Haeckel.

Spongocyclia orthogona, Haeckel, 1862, Monogr. d. Radiol., p. 471, Taf. xxviii. fig. 3.

Spongodiscus orthogonus, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 844.

Arms at different distances, forming a bilateral cross, grouped in two opposite pairs of equal size and similar form. Arms club-shaped, about as long as the diameter of the central circular disk, enveloped perfectly by the complete patagium, which forms a regular rectangle, the longer side of which is one and a half times as long as the shorter side. (The arms in my figure are not distinctly enough marked.)

Dimensions.—Radius of the arms 0.08, breadth 0.02; length of the larger side of the rectangle 0.15, of the smaller 0.1.

Habitat.—Mediterranean (Messina), surface.