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

Dictyocha triommata, Ehrenberg, 1845, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 76; Mikrogeol., Taf. xxxiii., Nr. xv. fig. 11.

Dictyocha triactis (= triacantha), Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 80.

Dictyocha trifenestrata, Ehrenberg, 1841, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 410; Mikrogeol., Taf. xix. fig. 38.

Dictyocha abyssorum, Ehrenberg, 1854, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 38.

Each pileated piece of the skeleton is a small three-sided pyramid, the sides of which form three triangular meshes; the three edges between them are three curved interradial beams, united in the centre (the apex of the pyramid). Alternating with these, three horizontal, perradial, centrifugal spines start from the base.

Dictyocha trigona, Zittel, 1876 (L. N. [29], p. 83, Taf. ii. fig. 6), is an interesting Cretaceous species, perhaps a variety of Dictyocha triommata.

Dimensions.—Diameter of the basal triangle 0.01, of the three meshes 0.005.

Habitat.—Fossil in different Tertiary deposits (of Sicily, Greece, North America); living in the Central Pacific, Stations 270 to 272, depth 2600 to 2925 fathoms.

5. Dictyocha tripyla, Ehrenberg.

Dictyocha tripyla, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 80.