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

All rings of the disk circular, concentric, of equal breadth, connected by numerous piercing radial beams. Chambers different in size, increasing from the centre towards the periphery. Pores regular, circular, one and half to two on the breadth of each ring.

Dimensions.—Diameter of the disk (with eight rings) 0.16; breadth of each ring 0.01; pores 0.003.

Habitat.—Fossil in many Tertiary rocks—Barbados, Sicily, Greece, &c.

Porodiscus haeckelii = Trematodiscus haeckelii, Bütschli, 1882, L. N. [41], Taf. xxiv. figs. 5a, 5b.

3. Porodiscus flustrella, n. sp. (Pl. [41], fig. 1).

Trematodiscus flustrella, Haeckel, 1866, MS. Canar. Ins.

All rings of the disk circular, concentric, of equal breadth, connected by numerous piercing radial beams. Chambers different in size, increasing from the centre towards the periphery. Pores very irregular, polygonal, or roundish, one to three on the breadth of each ring.

Dimensions.—Diameter of the disk (with six rings) 0.12; breadth of each ring 0.01; pores 0.002 to 0.006.

Habitat.—Cosmopolitan; Atlantic, Pacific, &c., many Stations, surface.

4. Porodiscus sorites, Haeckel.