Dimensions.—Diameter of the shell 0.09, pores 0.01 to 0.015, bars 0.002; length of the spines 0.06, basal breadth 0.01.
Habitat.—Central Pacific, Station 272, depth 2600 fathoms.
23. Hexastylus hirsutus, n. sp.
Shell thin walled, densely covered with bristle-shaped, radial spines, half as long as the six main spines. Pores irregular, polygonal, three to four times as broad as the bars; eight to ten on the radius. Six spines triangular pyramidal, as long as the radius, twice as broad as one pore.
Dimensions.—Diameter of the shell 0.14, pores 0.005 to 0.008, bars 0.002; length of the spines 0.06, basal breadth 0.01.
Habitat.—Central Pacific, Station 271, depth 2425 fathoms.
24. Hexastylus contortus, n. sp. (Pl. [21], fig. 12).
Shell thick walled, covered with bristle-shaped, radial spines, half as long as the radius. Pores irregular, roundish, two to three times as broad as the bars; seven to eight on the radius. Six spines triangular prismatic, in the distal half spirally twisted like a cork-screw (fig. 12); longer than the diameter of the shell, about as broad as one pore.
Dimensions.—Diameter of the shell 0.12, pores 0.006 to 0.008, bars 0.003; length of the spines 0.15, breadth 0.015.
Habitat.—Central Pacific, Station 265, depth 2900 fathoms.