Dimensions.—Diameter of the sphere 2.0 to 2.5, of the meshes 0.12 to 0.18; breadth of the tubes 0.01.
Habitat.—Antarctic Ocean, Station 157, depth 1950 fathoms.
3. Aulastrum dendroceros, n. sp. (Pl. [111], figs. 4a, b, c).
Radial tubes cylindrical, straight or slightly curved, thorny, forked at the distal end, two to three times as long as the thorny tangential tubes; the thorns are short and thin, partly simple, partly irregularly branched and scattered, arborescent. Meshes of the network irregularly polygonal, the majority pentagonal or tetragonal.
Dimensions.—Diameter of the sphere 2.4; radial tubes 0.2 to 0.3 long, 0.02 broad.
Habitat.—North Pacific, Station 241 to 244, surface.
4. Aulastrum triceros, n. sp. (Pl. [111], figs. 3, 3a).
Radial tubes cylindrical, straight, smooth, about twice as long as the smooth tangential tubes, armed with three divergent curved teeth at the distal end. Meshes subregular, pentagonal, intermingled with a small number of tetragonal and hexagonal meshes.
Dimensions.—Diameter of the sphere 1.2 to 1.8; radial tubes 0.15 long, 0.01 broad.
Habitat.—Tropical Atlantic, Station 349, depth 2450 fathoms.