Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, Second Part: Subclass Osculosa; Index / Report on the Scientific Results of the Voyage of H.M.S. Challenger During the Years 1873-76, Vol. XVIII

by Ernst Haeckel

Dimensions.—Height of the frontal ring 0.12, breadth 0.15.

Habitat.—South Pacific, Station 298, depth 2225 fathoms.

Subgenus 2. Tricyclonium, Haeckel.

Definition.—All three rings equal, circular.

3. Trissocyclus sphæridium, n. sp. (Pl. [93], fig. 12).

All three rings equal, circular, thorny; their rods prismatic, three-sided, with three denticulate edges; the teeth of the lateral edges become branched, and form by anastomoses of the branches small irregular meshes, which partly protect the eight large open gates.

Dimensions.—Diameter of the three rings 0.16, thickness 0.012.

Habitat.—Indian Ocean, Belligemma, Ceylon (Haeckel), surface

Family LI. Tympanida, Haeckel.

Parastephida, Haeckel, 1881, Prodromus, p. 446.