Habitat.—North Pacific, Station 224, depth 1850 fathoms.
2. Phacodiscus lentiformis, n. sp. (Pl. [35], fig. 8).
Disk with smooth surface, three and a half times as broad as the outer, and ten times as broad as the inner medullary shell. Pores regularly circular; twelve to thirteen on the radius of the disk. Margin of the disk sharp, as in a biconvex lens.
Dimensions.—Diameter of the disk 0.25, of the outer medullary shell 0.07, of the inner 0.025; pores 0.01.
Habitat.—Central Pacific, Station 265, depth 2900 fathoms; fossil in Barbados.
3. Phacodiscus grandis, n. sp.
Disk with thorny surface, five times as broad as the outer, and fifteen times as broad as the inner medullary shell. Pores regularly circular; twenty-two to twenty-four on the radius of the disk. Margin of the disk thick, rounded.
Dimensions.—Diameter of the disk 0.45, of the outer medullary shell 0.09, of the inner 0.03; pores 0.01.
Habitat.—Western Tropical Pacific, Station 225, depth 4475 fathoms.