7. Stylatractus sethoporus, n. sp. (Pl. [17], figs. 2, 3).
Cortical shell thick walled, smooth, with large irregular, roundish pores, twice to four times as broad as the bars; seven to eight on the half equator. At the bottom of each pore a thin lamella of silex, perforated by four to six irregular, roundish, double-contoured porules. Medullary shells resemble those of Stylatractus giganteus. Polar spines three-sided pyramidal; their length and basal thickness scarcely equal the diameter of the inner medullary shell.
Dimensions.—Major axis 0.15, minor axis 0.13; pores 0.02, bars 0.005, porules 0.01; length of the polar spines 0.04.
Habitat.—Pacific, central area, Station 272, depth 2600 fathoms.
Subgenus 4. Stylatractium, Haeckel.
Definition.—Network of the outer shell irregular, with meshes of different size and form; surface thorny or papillose, covered with small spinules or tubercles.
8. Stylatractus papillosus, n. sp.
Cortical shell thin walled, with papillose surface, and irregular, simple, roundish pores, ten to sixteen on the half equator, twice to three times as broad as the bars. Conical papillæ of the surface irregularly scattered. Polar spines conical, about as long as the main axis, at the base half as broad as the inner medullary shell.
Dimensions.—Major axis 0.12, minor 0.1; pores 0.006 to 0.01, bars 0.003; main axes of the medullary shells 0.09 and 0.06; length of the polar spines 0.13, basal breadth 0.04.
Habitat.—Indian Ocean, surface (between Socotra and Ceylon), Haeckel.