3. Plegmosphæra pachypila, n. sp.

Radius of the spherical shell-cavity about equal to the thickness of the spongy wall. Inside and outside of the wall closed by a smooth lattice-plate with irregular polygonal meshes, three to six times as broad as the bars.

Dimensions.—Diameter of the shell 0.24, of its cavity 0.12.

Habitat.—North Pacific, Station 250, surface.

Subgenus 2. Plegmosphærella, Haeckel.

Definition.—Inside of the spongy shell-wall closed by a smooth lattice-plate, outside rough, spongy, with prominent thorns.

4. Plegmosphæra entodictyon, n. sp.

Radius of the spherical shell-cavity half 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 0.24, of its cavity 0.08.

Habitat.—South Pacific, Station 300, surface.