Page:Scientific results HMS Challenger vol 18 part 1.djvu/759

Rh 3. Dicranastrum cornutum, n. sp. (Pl. 45, fig. 2).

Hagiastrum cornutum, Haeckel, 1879, Atlas (pl. xlv. fig. 2).

Four arms simply forked, four times as long as broad; each arm with two triangular diverging branches ending in strong conical spines. The simple basal part of each arm about of the same length as each branch of the distal part, twice as long as broad. Distance between the terminal spines of each arm nearly as great as its length.

Dimensions.—Radius of the arm 0.24, basal breadth 0.05; breadth across the bifurcation 0.12.

Habitat.—South Atlantic, Station 325, surface.

4. Dicranastrum antilope, n. sp.

Four arms simply forked, three times as long as broad; each arm with two lanceolate diverging branches, ending in strong angular spines. The simple basal part of each arm is twice as long as each branch of the distal part. Distance of the two terminal spines of each arm scarcely half as great as its length.

Dimensions.—Radius of the arm 0.32, basal breadth 0.11; breadth of the branches 0.07.

Habitat.—Tropical Atlantic (off Ascension), Station 342, surface.

Definition.—Each cross arm with three terminal branches, one middle (perradial) and two lateral (adradial) branches.

5. Dicranastrum wyvillei, n. sp. (Pl. 47, fig. 3).

Tricranastrum wyvillei, Haeckel, 1879, Natürl. Schöpfungsgesch., p. 705, Taf. xvi. fig. 5.

Arms trifid, one and a half times as long as broad; each arm with three blunt terminal branches of equal size. The simple basal part of each arm twice as long as the trifid distal part. (The central capsule depicted in fig. 3, Pl. 47, has the same form as the skeleton, and is only a little smaller.)

Dimensions.—Radius of the arm 0.4, basal breadth 0.12, greatest breadth (in the distal part) 0.24.

Habitat.—Pacific, central area, Station 271, surface.

6. Dicranastrum tricuspis, n. sp.

Arms trifid, twice as long as broad; each arm with three pointed terminal branches, ending in strong conical spines, the middle branch somewhat larger than the other two. The simple basal part of each arm three times as long as the trifid distal part.

Dimensions.—Radius of the arm 0.3, basal breadth 0.06, greatest breadth (in their distal part) 0.15.

Habitat.—North Pacific, Station 244, surface.