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.—Diameter of the gate 0.05 to 0.08; thickness of the ring 0.006 to 0.008.

Habitat.—Central Pacific, Stations 265 to 274, depth 2350 to 2925 fathoms.

2. Archicircus monostephus, n. sp. (Pl. [83], fig. 17).

Gate circular. Ring circular, with three elegantly denticulate edges (one outer median and two lateral edges). Transverse section of the ring triangular.

Dimensions.—Diameter of the gate 0.06 to 0.08; thickness of the ring 0.01 to 0.008.

Habitat.—Central Pacific, Station 274, depth 2750 fathoms.

3. Archicircus ellipsis, n. sp.

Gate elliptical. Ring elliptical, on the inner margin smooth, on the outer margin with fifteen to twenty equal, short, simple, or slightly forked thorns. Transverse section ovate.

Dimensions.—Diameter of the gate 0.05 to 0.09; thickness of the ring 0.01 to 0.014.

Habitat.—Western Tropical Pacific, Station 225, depth 4475 fathoms; also fossil in Barbados.