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 basal ring 0.025 to 0.03, of the apical ring 0.012 to 0.02.

Habitat.—North-west Pacific, Sea of Japan, Station 231, depth 2250 fathoms.

11. Distephanus octonarius, Haeckel.

Dictyocha octonaria, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 201.

Dictyocha polyactis, Ehrenberg, 1844, loc. cit., p. 80; Mikrogeol., 1854, Taf. xxii. fig. 50.

Dictyocha septenaria, Ehrenberg, 1844, loc. cit., p. 80; Mikrogeol., 1854, Taf. xxi. fig. 45.

Each pileate piece of the skeleton is a truncated eight-sided pyramid, composed of two regular octagonal rings, which lie in parallel plains, and are connected by eight radial beams. From the eight outer corners of the lower ring (or from the eight interradial meshes, between the eight perradial beams) start eight basal centrifugal spines. (This species is similar to Distephanus speculum, but has eight beams instead of six. In single pieces the number of the beams and meshes varies between seven and nine, the constant number being eight.) A seven-rayed variety is Dictyocha septenaria (loc. cit.), a nine-rayed Dictyocha polyactis.

Dimensions.—Diameter of the basal ring 0.02 to 0.03, of the apical ring 0.01 to 0.015.

Habitat.—Fossil in Tertiary rocks (Tripel and Marne from Caltanisetta, Sicily; Oran, Africa); living in the depths of the Atlantic, Station 348, and Pacific, Station 270, &c.

12. Distephanus octogonius, n. sp.