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

1. Amphitholus artiscus, n. sp. (Pl. [10], fig. 3).

Central chamber of the same height as both cupolas. Surface of the cortical shell rough. Pores regular, circular, with prominent hexagonal frames, twice as broad as the bars; eight to ten in the basal semicircle of one cupola.

Dimensions.—Major axis of the shell 0.16, minor axis 0.1; pores 0.008, bars 0.004.

Habitat.—Pacific, central area, Station 272, depth 2600 fathoms.

2. Amphitholus artidium, n. sp.

Central chamber one-fourth higher than both cupolas. Surface of the cortical shell smooth. Pores irregular, roundish, once to three times as broad as the bars. (Very similar to Tholartus tricolus, Pl. [10], fig. 1, but different by the medullary shell.)

Dimensions.—Major axis of the shell 0.15, minor axis 0.12; pores 0.004 to 0.01, bars 0.003.

Habitat.—North Pacific, Station 241, depth 2300 fathoms.

Subgenus 2. Amphitholura, Haeckel.

Definition.—Surface of the shell with radial spines or thorns.