Habitat.—Central Pacific, Station 270, surface.
2. Hexaconus coronatus, n. sp. (Pl. [139], fig. 5).
All six hydrotomical spines of equal size, conical, somewhat compressed, with two prominent edges, scarcely as long as the radius of the shell. Sheaths crested, strongly dentated on the mouth, three times as broad as long and only one-sixth as long as the spines. Fourteen smaller spines about half as large as the six principal spines, of the same form, but without coronated sheaths.
Dimensions.—Diameter of the shell 0.2; length of the six hydrotomical spines 0.1; basal breadth 0.02.
Habitat.—North Pacific, Station 253, surface.
3. Hexaconus velatus, n. sp. (Pl. [139], fig. 6).
All six hydrotomical spines of equal size, conical, somewhat compressed, shorter than the radius of the shell. Sheaths very large, truncated conical, enveloping the spines almost entirely, with crested wall, only half as broad at the constricted mouth as at the base. The fourteen smaller spines about half as large as the six principal spines, of the same form, but without large sheaths.
Dimensions.—Diameter of the shell 0.12; length of the six hydrotomical spines 0.05; basal breadth 0.01.
Habitat.—North Atlantic, Station 354, surface.