Definition.—Surface of the shell smooth or rough, without radial spines.
1. Spongodruppa terebintha, n. sp.
Cortical shell one and a third times as long as broad, with smooth surface, three times as broad as the spherical medullary shell. Spongy framework very compact, with small meshes of the same breadth as the bars. Thickness of the spongy wall equal to the radius of the medullary shell.
Dimensions.—Length of the cortical shell (or major axis of the ellipsoid) 0.16, breadth (or minor axis) 0.12; thickness of its wall 0.02; medullary shell 0.04.
Habitat.—Western Tropical Pacific, Station 225, depth 4475 fathoms.
2. Spongodruppa pistacia, n. sp.
Cortical shell one and a half times as long as broad, with thorny surface, nearly five times as broad as the spherical medullary shell. Spongy framework compact, its thickness equal to the diameter of the medullary shell.
Dimensions.—Length of the cortical shell 0.2, breadth 0.14; thickness of its wall 0.03; medullary shell 0.03.
Habitat.—Fossil in the rocks of Barbados.
3. Spongodruppa lentisca, n. sp.