Habitat.—Pacific, central area, Station 271, depth 2425 fathoms.
2. Cenolarcus dimensivus, n. sp.
Network of the shell regular, with circular pores (without hexagonal frames), three times as broad as the thin bars; about twelve pores on the half meridian, nine on the half equator. Surface thorny. Proportion of the three dimensive axes = 3 : 4 : 5.
Dimensions.—Principal axis 0.15, transverse axis 0.12, sagittal axis 0.09; pores 0.012, bars 0.004.
Habitat.—North Pacific, Station 244, surface.
3. Cenolarcus triaxonius, n. sp.
Network of the shell regular, with circular, hexagonally framed pores, four times as broad as the thin bars; about twelve pores on the half meridian, nine on the equator. Surface smooth. From the inner surface of the shell arise six very thin radial beams, opposite in pairs in the three dimensive axes; all six beams end freely in a little knob, at an equal distance from the centre; therefore this remarkable species seems to have lost a medullary shell (descending from Coccolarcus or Larnacilla?). Proportion of the three dimensive axes = 2 : 2.5 : 3.
Dimensions.—Principal axis 0.13, transverse axis 0.11, sagittal axis 0.09; pores 0.012, bars 0.03.
Habitat.—Tropical Atlantic, Station 338, depth 1990 fathoms.
4. Cenolarcus lentellipticus, n. sp.