Habitat.—North Pacific, Station 241, depth 2300 fathoms.
2. Ellipsostylus avicularis, n. sp.
Proportion of the major axis to the minor = 3 : 2. Shell thick walled, with regular, rosette-shaped meshes, three times as broad as the bars; ten to twelve on the half equator. Every mesh on the outer margin with five to six rounded lobes, as in Xiphostylus phasianus (Pl. [13], fig. 9). Surface smooth. Polar spines sharp edged, thick; the longer straight and equal to the longer axis, the shorter half as long, shaped like a bird's head.
Dimensions.—Longer axis 0.18, shorter axis 0.12; pores 0.015, bars 0.005.
Habitat.—South Pacific, Station 300, depth 1375 fathoms.
3. Ellipsostylus psittacus, n. sp. (Pl. [13], fig. 6).
Proportion of the major axis to the minor = 4 : 3. Shell thin walled, with regular or subregular rosette-shaped meshes, twice as broad as the bars; eight to nine on the half equator; each mesh with three to four rounded lobes. Surface smooth. Polar spines sharp edged, very unequal; longer spine about twice as long as the major axis, somewhat curved; shorter spine scarcely longer than the radius, shaped like a bird's head.
Dimensions.—Longer axis 0.08, shorter axis 0.06; pores 0.01, bars 0.005; length of the polar spines—longer 0.15, shorter 0.05.
Habitat.—Central area of the Pacific, Station 266, depth 2750 fathoms.
4. Ellipsostylus aquila, n. sp. (Pl. [13], fig. 1).