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.—Breadth of the mitral ring 0.06, of the basal ring 0.11.

Habitat.—Central Pacific, Station 268, depth 2900 fathoms.

2. Circotympanum octogonium, n. sp. (Pl. [94], fig. 17).

Mitral and basal rings octagonal, the latter one and a half times as broad as the former. Eight columellæ slightly curved, thorny. The mitral ring bears on each corner a short ascending spine, the basal ring a larger, thorny, obliquely descending spine, which has some recurved thorns on the upper edge. All rods more or less thorny.

Dimensions.—Breadth of the mitral ring 0.06, of the basal ring 0.09.

Habitat.—Central Pacific, Station 271, depth 2425 fathoms.

3. Circotympanum decagonium, n. sp.

Mitral and basal rings circular, the latter nearly twice as broad as the former, both armed with scattered irregular thorns. Ten columellæ smooth, curved.

Dimensions.—Breadth of the mitral ring 0.07, of the basal ring 0.12.

Habitat.—North Pacific, Station 244, depth 2900 fathoms.