Dimensions.—Radius of each arm 0.25, basal breadth 0.04, distal breadth 0.12.
Habitat.—Pacific, central area, Station 273, surface.
Subgenus 2. Dictyastromma, Haeckel.
Definition.—Arms on the distal end provided with terminal spines.
5. Dictyastrum trispinosum, n. sp. (Pl. [43], fig. 5).
Rhopalastrum trispinosum, Haeckel, 1881, Prodromus et Atlas (pl. xliii. fig. 5).
Arms trapezoid, at the rounded distal end twice as broad as at the base, with a strong and short, conical, terminal spine. Diameter of the circular central disk about equal to the length and the greatest breadth of the arms.
Dimensions.—Radius of each arm 0.15, basal breadth 0.06, distal breadth 0.11.
Habitat.—Equatorial Atlantic, Station 347, surface.
6. Dictyastrum triactis, Ehrenberg.