Radial tubes cylindrical, straight, smooth, two to three times as long as the smooth, cylindrical, tangential tubes; armed at the distal end with three divergent terminal teeth, which are straight or slightly curved and about one-third as long as the tube.
Dimensions.—Diameter of the sphere 1.2; tangential tubes 0.1 long, 0.01 broad.
Habitat.—North-Eastern Pacific (off Japan), Station 231, surface.
5. Aulosphæra tetrodon, n. sp.
Radial tubes slender, cylindrical, straight, smooth, about three times as long as the smooth, cylindrical, tangential tubes; armed at the distal end with a regular cross of four terminal teeth, which are directed almost horizontally, and are slightly recurved (just as in Aulosphæra spathillata, Pl. [109], fig. 7, but longer and without lateral verticils).
Dimensions.—Diameter of the sphere 1.6; tangential tubes 0.15 long, 0.005 broad.
Habitat.—South Pacific, Station 289, depth 2550 fathoms.
6. Aulosphæra polyodon, n. sp.
Radial tubes slender, spindle-shaped, gradually tapering towards the two ends, smooth, about twice as long as the cylindrical, smooth, tangential tubes; armed at the distal end with a verticil of twelve to twenty or more divergent, conical, slightly curved teeth.
Dimensions.—Diameter of the sphere 3.3; tangential tubes 0.2 long, 0.01 broad.