Habitat.—Central Pacific, Station 271, depth 2425 fathoms.
3. Cromyosphæra bigemina, n. sp.
Radial proportion of the four spheres = 1 : 2 : 7 : 8. Outer cortical shell smooth, with regular hexagonal pores and very thin bars; inner cortical shell with the same number of exactly corresponding, regular circular pores. Both medullary shells with regular circular pores of the same breadth as the bars. (Somewhat similar to Hexacromyon elegans, Pl. [24], fig. 9, also with six inner radial beams, but without external radial spines.)
Dimensions.—Diameter of the four spheres—(A) 0.2, (B) 0.17, (C) 0.05, (D) 0.025.
Habitat.—North Pacific, Station 241, depth 2300 fathoms.
4. Cromyosphæra cepa, n. sp.
Radial proportion of the four spheres = 1 : 2 : 4 : 5. All four shells of the same structure, thick-walled, with regular circular pores, two to four times as broad as the bars; the size of the pores increases gradually from the inner to the outer shell. Surface thorny. Distance between the second and third shells twice as great as that between the others.
Dimensions.—Diameter of the four spheres—(A) 0.125, (B) 0.1, (C) 0.05, (D) 0.025.
Habitat.—Fossil in Barbados.
5. Cromyosphæra scorodonium, n. sp.