(very similar to Xiphostylus phasianus, Pl. 13, fig. 9, but different in the equal size and similar form of the two large polar spines).
Dimensions.—Diameter of the sphere 0.12, pores 0.015, bars 0.005; length of the polar spines 0.1 to 0.2, basal breadth 0.02.
Habitat.—Indian Ocean, Cocos Islands, surface, Rabbe.
5. Xiphosphæra hebe, n. sp.
Pores regular, circular, three times as broad as the bars. On the half equator sixteen to twenty pores. Shell thick walled; surface smooth. Polar spines conical or nearly cylindrical, about as long as the axis of the sphere, as broad at the base as two pores.
Dimensions.—Diameter of the sphere 0.1 to 0.13, pores 0.006, bars 0.002; polar spines 0.1 to 0.15 long, 0.01 thick.
Habitat.—Pacific, central area, Stations 265 to 268, depths 2700 to 2900 fathoms.
6. Xiphosphæra maxima, n. sp.
Pores regular, circular, twice as broad as the bars, funnel-shaped. Twenty to thirty pores on the half equator. Shell very thick walled; surface smooth. Polar spines three-sided pyramidal, about as long as the radius of the sphere, as broad at the base as two pores.
Dimensions.—Diameter of the sphere 0.22 to 0.35, pores 0.008 to 0.01, bars 0.005; polar spines 0.1 to 0.15 long, 0.02 thick.
Habitat.—Equatorial Atlantic, Station 347, depth 2250 fathoms.
7. Xiphosphæra euphrosyne, n. sp.
Pores regular, circular, about as broad as the bars, double contoured. Eight to ten on the half equator. Shell thin walled; surface smooth. Polar spines conical, about as long as the radius of the sphere, as broad at the base as one pore.
Dimensions.—Diameter of the sphere 0.12 to 0.15, pores and bars 0.02; polar spines 0.06 to 0.09 long, 0.02 thick.
Habitat.—South Atlantic, Station 323, depth 1900 fathoms.
Subgenus 2. Xiphosphærella, Haeckel.
Definition.—Pores of the spherical shell regular, of nearly equal size and form; surface thorny or spiny, covered with regularly distributed papillæ or thorns (in addition to the two large polar spines).
8. Xiphosphæra pallas, n. sp. (Pl. 14, fig. 4).
Pores regular, circular, separated by hexagonal elevated frames, the sharp crest of which is elegantly denticulated; in each corner of the hexagons (between three pores) is a short radial spine,
