5. Plegmosphæra leptodictyon, n. sp.
Radius of the spongy shell-cavity six times as great as the thickness of the spongy wall. Inside of the wall closed by a smooth lattice-plate, outside rough spongy.
Dimensions.—Diameter of the shell 0.44, of its cavity 0.36.
Habitat.—Central Pacific, Station 266, surface.
Subgenus 3. Plegmosphæromma, Haeckel.
Definition.—Inside of the spongy shell-wall rough spongy, without lattice-plate, outside closed by a smooth lattice-plate.
6. Plegmosphæra exodictyon, n. sp. (Pl. [18], fig. 8).
Radius of the spongy shell-cavity only one-fourth as great as the thickness of the spongy shell-wall. Outside of the wall closed by a smooth lattice-plate, inside rough, spongy.
Dimensions.—Diameter of the shell 0.4, of its cavity 0.08.
Habitat.—South Atlantic, Station 325, surface.