Habitat.—Indian Ocean, western part (Zanzibar), Pullen, depth 2200 fathoms.
6. Cyphonium mammarium, n. sp.
Cortical shell thick walled, with smooth surface (sometimes a little rough); pores irregular, roundish, twice to three times as broad as the bars; eleven to twelve on the half meridian of each chamber, sixteen to nineteen on its half equator. Internal medullary shell spherical, external lenticular compressed, sometimes both spherical or both compressed. (Resembles the internal cortical twin-shell of Cyphocolpus virginis, Pl. [40], fig. 11.)
Dimensions.—Main axis 0.14, equatorial axis 0.08, greatest breadth 0.09; pores 0.004 to 0.006, bars 0.002.
Habitat.—South Pacific, Station 285, depth 2375 fathoms.
Subgenus 2. Ommatocyrtis, Haeckel.
Definition.—Surface of the cortical shell thorny or spiny.
7. Cyphonium hexagonium, n. sp.
Didymocyrtis hexagonia, Haeckel, 1881, Prodromus.
Cortical shell thin walled, with spiny surface; pores regular or subregular, hexagonal, twice to three times as broad as the bars; five to six on the half meridian, nine to ten on the half equator of each chamber. Radial spines between them conical, about as long as the pores. Medullary shells both spherical.