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.
Subgenus 2. Tricranastrum, Haeckel, 1881, Prodromus, p. 460.
Definition.—Each cross arm with three terminal branches, one middle (perradial) and two lateral (adradial) branches.