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. Tripodictya trigonaria, n. sp. (Pl. [42], fig. 8).

All rings of the disk concentric, triangular, with three equal convex sides, all of the same breadth; first and second rings with three simple chambers, third and fourth rings with six chambers, fifth ring with twelve chambers. Central chamber also equilateral triangular, from its three corners arise three piercing perradial beams; from the second ring arise three interradial beams, alternate with the latter; from the fourth ring between these and the former arise six adradial beams. Pores subregular, two on the breadth of each ring. Three marginal spines pyramidal, as long as the radius of the disk and as broad as one ring.

Dimensions.—Diameter of the disk (with five rings) 0.11; breadth of each ring 0.011; pores 0.004.

Habitat.—Pacific, central area, Station 265, depth 2900 fathoms.

2. Tripodictya triacantha, n. sp. (Pl. [42], fig. 7).

All rings of the disk concentric, circular, of the some breadth, connected by very numerous irregular radial beams, the number of which increases towards the periphery. Pores irregular, roundish, two on the breadth of each ring. Three marginal spines spindle-shaped, as long as the radius of the disk, and in the middle part as broad as one ring.

Dimensions.—Diameter of the disk (with eight rings) 0.2; breadth of each ring 0.012; pores 0.004.

Habitat.—North Pacific, Station 253, depth 3125 fathoms.

3. Tripodictya tribelonia, n. sp. (Pl. [42], fig. 9).

All rings of the disk, or a part of them, not concentric, spirally convoluted, of equal breadth, connected by numerous irregular, interrupted radial beams, the number of which increases from the centre. (In one marginal view of the disk, Pl. [42], fig. 9, the disk seemed to be composed of seven parallel chambered plates in the central part, and five similar plates in the peripheral part.) Pores irregular, roundish, three on the breadth of each ring. Three marginal spines long and thin, cylindrical (as in Staurodictya cruciata, Pl. [42], fig, 4), longer than the diameter of the disk, and half as thick as one ring.