Shell nut-shaped, mammillate, without external stricture, but with complete external sagittal ring. Pores subregular, circular. Basal plate with four large central pores, surrounded by a circle of twelve to twenty small peripheral pores. Apical horn very large, spindle-shaped, one and a half times as long as the shell. Feet twenty-five to thirty, broadly lamellar, truncate, divergent, about as long as the shell.
Dimensions.—Shell 0.11 long, 0.13 broad; horn 0.15 long, feet 0.09 long.
Habitat.—Central Pacific, Station 272, depth 2600 fathoms.
16. Petalospyris furcata, n. sp.
Shell nut-shaped, smooth, with sharp sagittal stricture. Pores numerous, small, and circular; no larger annular pores. Basal plate with four larger and four alternate pairs of smaller pores. Horn conical, about as long as the shell. Feet fifteen to twenty, broadly lamellar, about twice as long as the shell, in the distal half forked.
Dimensions.—Shell 0.04 long, 0.06 broad; horn 0.05 long, feet 0.1 long.
Habitat.—South Pacific, Station 300, depth 1375 fathoms.
17. Petalospyris lobata, n. sp. (Pl. [87], fig. 13).
Shell subspherical, smooth, with slight sagittal stricture. Pores small, roundish; on each side of the ring two pairs of larger annular pores. Basal plate with four pores. Horn stout, three-sided prismatic, half as long as the shell. Feet twelve to sixteen, lamellar, lobate (the most part with three lobes), nearly vertical, about as long as the shell.
Dimensions.—Shell diameter 0.05; horn 0.03, feet 0.05 long.