1. Aulatractus fusiformis, n. sp. (Pl. [111], figs. 6, 6a, 6b).
Shell spindle-shaped, about twice as long as broad, rounded at both poles of the main axis. Tangential tubes smooth, cylindrical. Radial tubes of the same length as the tangential tubes, but much thinner, slender cylindrical, studded with perpendicularly arising, short, lateral branches, which are scattered in the proximal part, verticillate in the distal part, and bear a spinulate terminal knob.
Dimensions.—Length of the shell 7.5 to 10.0, breadth 3.5; length of the radial tubes 0.15 to 0.18, breadth 0.004.
Habitat.—Tropical Atlantic, Stations 348, 349; surface, and in various depths.
2. Aulatractus diploconus, n. sp. (Pl. [111], fig. 7).
Shell diploconical or nearly spindle-shaped, about three times as long as broad, equally pointed at the two poles of the main axis, not inflated in the middle part. Radial tubes slenderly conical, thorny, only half as long as the smooth tangential tubes.
Dimensions.—Length of the shell 6.0 to 8.0, breadth 2.2 to 4.5; length of the radial tubes 0.1 to 0.15, breadth 0.007.
Habitat.—North Atlantic, Canary Islands, Station 353, surface.
3. Aulatractus fusulus, n. sp.
Shell spindle-shaped, about twice as long as broad, pointed at the two equal poles of the main axis. Radial tubes cylindro-conical, smooth, about as long as the smooth tangential tubes. This species resembles in its simple structure the common cosmopolitan Aulosphæra trigonopa, and differs from it only in the constant spindle-form of the shell.