Subgenus 1. Drymosphærella, Haeckel.
Definition.—Radial by-spines simple, not branched (main spines simple).
1. Drymosphæra hexagonalis, n. sp.
Inner shell with regular, hexagonal meshes and very thin thread-like bars; outer shell twice as broad, with simple triangular meshes and thin thread-like bars, which bear very numerous, bristle-shaped radial by-spines. Radial main spines with three smooth edges. (Differs from the first species of the other three genera of Diplosphærida in the presence of by-spines on the outer, and their absence on the inner shell.)
Dimensions.—Diameter of the outer shell 0.32, inner 0.16.
Habitat.—Central Pacific, Station 274, surface.
2. Drymosphæra polygonalis, n. sp. (Pl. [19], fig. 1).
Diplosphæra polygonalis, Haeckel, 1879, Atlas.
Inner shell with irregular, polygonal meshes and very thin thread-like bars; outer shell one and a half times as broad, with simple triangular meshes and thicker bars, which bear numerous bristle-shaped radial by-spines (in the figure the majority of these are broken off). Radial main spines with three smooth edges. (Similar to Leptosphæra polygonalis and Diplosphæra polygonalis, but differs from both in the presence of by-spines on the outer, and their absence on the inner shell.)
Dimensions.—Diameter of the outer shell 0.33, inner 0.22.