Dimensions.—Diameter of the disk 0.17, of the medullary shell 0.07; length of the marginal spines 0.02 to 0.04, basal breadth 0.01 to 0.02.
Habitat.—Fossil in Tertiary rocks of Sicily, Grotte, Stöhr.
Subgenus 2. Heliodendrum, Haeckel.
Definition.—Surface of the disk armed with simple or branched radial spines.
4. Heliodrymus setosus, n. sp.
Disk with spiny surface, four times as broad as the medullary shell. Pores regular, circular; twelve to thirteen on the radius. Marginal spines ten to twelve, cylindrical, irregularly branched, each with two to eight flexuose branches of different sizes; the largest as long as the diameter of the disk. Spines of the surface bristle-shaped, half as long, not branched.
Dimensions.—Diameter of the disk 0.2, of the medullary shell 0.05; length of the marginal spines 0.12 to 0.18, breadth 0.025.
Habitat.—North Pacific, Station 254, surface.
5. Heliodrymus ramosus, n. sp. (Pl. [35], figs. 3, 4).
Disk with spiny surface, three times as broad as the medullary shell. Pores regular, circular, hexagonally framed; eleven to twelve on the radius. Marginal spines sixteen to twenty, cylindrical, about as long as the radius, irregularly forked or branched, with unequal flexuose branches. Spines of the surface nearly as long, bristle-shaped, also irregularly branched.