Radial tubes slenderly spindle-shaped, slightly curved, gradually tapering from the middle towards both ends. The proximal two-thirds of the tubes enclosed in the calymma are smooth; the distal freely prominent third is armed with six to eight equidistant verticils of small conical teeth (ten to fifteen in each verticil).
Dimensions.—Length of the tubes 0.5 to 1.5, breadth 0.02.
Habitat.—South Pacific, Station 289, depth 2550 fathoms.
2. Aulactinium actinelium, n. sp. (Pl. [101], fig. 8).
Radial tubes cylindrical, straight, slightly tapering towards both ends. Proximal two-thirds smooth, the distal third studded with numerous small recurved thorns.
Dimensions.—Length of the tubes 0.6 to 0.9, breadth 0.02.
Habitat.—South Pacific, Station 293, depth 2025 fathoms.
3. Aulactinium actinosphærium, n. sp.
Radial tubes cylindrical, straight, smooth, of nearly equal breadth throughout their whole length, without thorns and spathillæ, pointed at both ends.
Dimensions.—Length of the tubes 1.6 to 2.2, breadth 0.02 to 0.03.