Dimensions.—Medullary shell 0.06 long, 0.05 broad; cortical shell 0.16 long and broad; gates 0.05 high, 0.09 broad.
Habitat.—South Atlantic, Station 330, surface.
10. Tetrapyle staurophora, n. sp.
Cortical shell thorny, with four strong radial spines, two on the poles of the longitudinal axis, two on the poles of the transverse axis. Lateral girdle elliptical, one and a half times as long as broad. Four gates nearly hexagonal, quite as high as broad. On each half wing of the transverse girdle three to four longitudinal rows of irregular, roundish pores.
Dimensions.—Medullary shell 0.06 long, 0.04 broad; cortical shell 0.18 long, 0.12 broad; gates 0.08 high and broad.
Habitat.—Western Tropical Atlantic, coast of Brazil, Rabbe, surface.
11. Tetrapyle quadricornis, n. sp.
Cortical shell thorny, with four strong horn-like curved spines, lying in the lateral plane and converging in pairs towards the poles of the transverse axis. Lateral girdle elliptical, one and a third times as long as broad. Four gates kidney-shaped, twice as broad as high. On each half wing of the transverse girdle four to five rows of irregular, roundish pores. (May be only the young form of Pylonium quadricorne, Pl. [9], fig. 14.)
Dimensions.—Medullary shell 0.05 long, 0.04 broad; cortical shell 0.16 long, 0.12 broad; gates 0.03 high, 0.07 broad.
Habitat.—Pacific, central area, Stations 270 to 274, surface.