length. Thorax slenderly conical, or bottle-shaped, with little convex outlines; three to four times as long as broad, papillate, with regular, circular pores, which are included by rhombic frames, and increase in size towards the mouth.
Dimensions.—Cephalis 0.004 diameter, thorax 0.12 long, 0.035 broad.
Habitat.—Indian Ocean (Zanzibar), depth 2200 fathoms (Pullen).
14. Sethoconus orthoceras, n. sp. (Pl. 54, fig. 11).
Cephalis very small, conical, hyaline, without pores, with a double internal stricture, and a very short, rudimentary horn. Thorax slenderly conical, with undulate outlines, three to four times as long as broad, with subregular, roundish pores, gradually increasing in size towards the mouth.
Dimensions.—Cephalis 0.02 long, 0.01 broad; thorax 0.16 long, 0.04 to 0.08 broad.
Habitat.—South Atlantic, Station 325, surface.
15. Sethoconus profundus, Haeckel.
Cornutella profunda, Bailey, 1856, Amer. Jour., vol. xxii. pl. i. fig. 23.
Cornutella profunda, Haeckel, 1862 Monogr. d. Radiol., p. 284.Cephalis very small, spherical, hyaline without pores and internal stricture, with a very short, rudimentary horn. Thorax slenderly conical with straight outlines, three to four times as long as broad, with subregular, circular pores, gradually increasing in size towards the mouth.
Dimensions.—Cephalis 0.004 to 0.008 diameter, thorax 0.08 to 0.12 long, 0.03 to 0.04 broad.
Habitat.—Cosmopolitan; Mediterranean, Atlantic, Indian, Pacific; at various depths.
16. Sethoconus trichostylus, Haeckel.
Cephalis very small, conical, hyaline, without pores, with a very long, bristle-shaped, spirally twisted horn, longer than the whole shell. Thorax slenderly conical, with straight outlines, and very small, regular, circular pores of nearly equal size, which are separated by broader bars and spirally ascending oblique crests (according to the figure).
Dimensions.—Cephalis 0.004 long, 0.002 broad; thorax 0.06 long, 0.04 broad.
Habitat.—North Pacific (California), depth 2600 fathoms.
17. Sethoconus longisetus, Haeckel.
Cephalis very small, spherical, hyaline, without pores, with a very long, bristle-shaped horn,
