Cortical shell one and a half times as long as broad, with rough surface, five to six times as large as the ellipsoidal outer medullary shell. Spongy framework loose, with large meshes, its thickness about equal to the outer medullary shell.
Dimensions.—Length of the cortical shell 0.26, breadth 0.18; thickness of its wall 0.04; size of the outer medullary shell 0.045 to 0.035, of the inner 0.015.
Habitat.—Equatorial Atlantic, Station 348, depth (2450) fathoms.
4. Spongoliva amygdalina, n. sp.
Cortical shell twice as long as broad, with thorny surface, ten times as long as the small spherical outer medullary shell. Spongy framework loose, with large meshes, its thickness one and a half times as large as the outer medullary shell.
Dimensions.—Length of the cortical shell 0.3, breadth 0.16; thickness of its wall 0.045; size of the outer medullary shell 0.03, of the inner 0.015.
Habitat.—Fossil in the Tertiary rocks of Sicily (Caltanisetta).
Subgenus 2. Spongolivina, Haeckel.
Definition.—Surface of the shell armed with radial spines.
5. Spongoliva opuntina, n. sp.