_Habitat._--Fossil in Barbados. 12. _Petalospyris papillata_, n. sp. Shell nearly cubical, papillate, without external sagittal stricture, with small, irregular, roundish pores. Basal plate with six pores (three larger and three alternate smaller). Apical horn conical, half as long as the shell. Feet twenty to thirty, one-half to one-third as long, conical, divergent. _Dimensions._--Shell diameter 0.09; horn 0.04 long, feet 0.03 to 0.05 long. _Habitat._--North Atlantic, Station 353, depth 2965 fathoms. 13. _Petalospyris dictyocubus_, n. sp. (Pl. 86, fig. 6). Shell nearly cubical, smooth, without external stricture, but with a complete, parietal, square, sagittal ring. On each side of the ring four pairs of larger pores, whilst the lateral pores are smaller and more numerous. Basal plate also with four pairs of larger pores and smaller lateral pores. Apical horn and basal feet short, pyramidal, scarcely one-fourth as long as the shell. The three primary feet are larger than the six to nine secondary feet. _Dimensions._--Shell diameter 0.08; horn and feet 0.02 long. _Habitat._--Central Pacific, Station 274, surface. 14. _Petalospyris bellidiastrum_, n. sp. Shell nut-shaped, tuberculate, with slight sagittal stricture and irregular, roundish pores. Basal plate with twelve pores (four central larger and eight peripheral smaller pores). Apical horn slender, conical, about as long as the shell (sometimes ramified at the distal end). Feet sixteen to twenty, broadly lamellar, truncate, divergent, about as long as the shell. _Dimensions._--Shell 0.08 long, 0.1 broad; horn and feet 0.07 to 0.09 long. _Habitat._--Central Pacific, Station 265, depth 2900 fathoms; also fossil in Barbados. 15. _Petalospyris dinoceras_, n. sp. (Pl. 87, fig. 12). 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. {1064}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).