14. Stylosphæra terpsichore, n. sp.
Radial proportion of the two shells = 3 : 1 or 4 : 1. Cortical shell thick walled, smooth, with irregular, roundish pores, one to three times as broad as the bars; fifteen to twenty-five on the half equator. Polar spines conical, about as long as the axis of the outer sphere, as broad at the base as the inner shell.
Dimensions.—Diameter of the outer shell 0.15 to 0.2, pores 0.005 to 0.02, bars 0.004 to 0.008; inner shell 0.05; length of the polar spines 0.15 to 0.25, basal breadth 0.05.
Habitat.—Western Indian Ocean, Zanzibar, depth 2200 fathoms, Pullen.
Subgenus 4. Stylosphæromma, Haeckel.
Definition.—Pores of the cortical shell irregular, of different size or form; surface spiny or thorny.
15. Stylosphæra thalia, n. sp.
Radial proportion of the two shells = 2 : 1. Cortical shell thin walled, thorny, with irregular, roundish pores, two to four times as broad as the bars; eight to twelve on the half equator. Polar spines conical, one to one and a half times as long as the axis of the outer sphere, one-fourth to one-sixth as thick at the base. (Resembles Sphærostylus ophidium, Pl. [16], fig. 14, but differs in the straight regular conical polar spines, both of equal length and similar form.)
Dimensions.—Diameter of the outer shell 0.12, pores 0.01 to 0.02, bars 0.005; inner shell 0.06; polar spines 0.1 to 0.16 long, 0.03 broad.
Habitat.—South Pacific, Station 302, depth 1450 fathoms.