Six main spines triangular pyramidal, with spirally contorted prominent edges, as long as the radius, as broad at the base as one pore.
Dimensions.—Diameter of the shell 0.13, pores 0.01, bars 0.002; length of the spines 0.06 to 0.8, basal breadth 0.01.
Habitat.—Central Pacific, Station 266, depth 2750 fathoms.
12. Hexastylus cochleatus, n. sp. (Pl. 21, fig. 1).
Shell thick walled, covered with numerous short, conical spines (about as large as one pore). Pores regular, circular, three times as broad as the bars; eight to nine on the radius. Six main spines triangular pyramidal, with prominent, spirally-twisted edges, as long as the diameter of the shell, and twice as broad at the base as one pore.
Dimensions.—Diameter of the shell 0.17, pores 0.015, bars 0.005; length of the spines 0.16, breadth 0.03.
Habitat.—Mediterranean, Corfu, Haeckel, surface.
13. Hexastylus setosus, Haeckel.
Shell thin walled, covered with numerous short, bristle-shaped spines (not larger than one pore). Pores regular, circular, four times as broad as the bars; thirteen to sixteen on the radius. Six main spines three-sided pyramidal, scarcely one-third as long as the radius. (In the figure of Ehrenberg, loc. cit., only four spines are in regular, crossed disposition, two others opposite in oblique direction; this is either an individual abnormality, or an error of drawing; the same species occurs with six spines exactly regularly disposed in the three dimensive axes.)
Dimensions.—Diameter of the shell 0.15; pores 0.008, bars 0.002; length of the spines 0.02 to 0.03, basal breadth 0.005.
Habitat.—Indian Ocean, Zanzibar, Pullen; Madagascar, Rabbe.
14. Hexastylus chilonis, n. sp.
Shell thin walled, covered with numerous bristle-shaped spines (as long as the radius). Pores regular, circular, twice as broad as the bars; eight to nine on the radius. Six main spines triangular pyramidal, with straight edges, as long as the diameter of the shell, as broad as two pores.
Dimensions.—Diameter of the shell 0.2, pores 0.02, bars 0.01; length of the spines 0.2, basal breadth 0.05.
Habitat.—South Atlantic, Station 325, surface.
15. Hexastylus cleobuli, n. sp.
Shell thick walled, covered with numerous short, conical spines (twice as large as one pore). Pores regular, circular, of the same breadth as the bars; twelve to thirteen on the radius. Six main spines conical, as long as the radius, three times as broad as one pore.
