1. Porocapsa murrayana, n. sp. (Pl. [133], fig. 7).
Perspinal holes cruciform, with smooth thickened margin or with four short teeth between the four lobes. Porules of the shell simple, without ring and dimple. Four edges of the spines smooth. (Differs from Sphærocapsa cruciata, Pl. [135], figs. 6, 7, living in the same locality, mainly in the reduction of the radial spines, which do not reach the shell.)
Dimensions.—Diameter of the shell 0.28; length of the spines 0.2.
Habitat.—North Atlantic, Færöe Channel, Gulf Stream (expedition of H.M.S. "Triton," August 1882), John Murray, surface and in depths from 40 to 640 fathoms.
2. Porocapsa tetrodon, n. sp.
Perspinal holes cruciform, with four triangular prominent teeth between the four lobes of the cross. Porules of the shell with an elevated polygonal ring, in the bottom of a dimple. Four edges of the spines elegantly denticulate.
Dimensions.—Diameter of the shell 0.36; length of the spines 0.12.
Habitat.—North Pacific, Station 253, surface.
3. Porocapsa octodon, n. sp.
Perspinal holes square, with four larger prominent teeth on the sides of the square, and four smaller teeth on its corners. Porules of the shell surrounded by an elevated ring with elegantly crenated irregular margin. Four edges of the spines smooth.