Dimensions.—length of the tubes 1.0 to 2.0, breadth 0.02 to 0.03; branches 0.15 to 0.3.
Habitat.—Indian Ocean, Ceylon (south of Matura), Haeckel, surface.
Subgenus 2. Auloceratium, Haeckel.
Definition.—Distal ends of the terminal branches with a spathilla, or a small corona of radial, usually recurved teeth.
6. Auloceros dicranaster, n. sp. (Pl. [105], figs. 14, 15).
Radial tubes cylindrical, straight, equally broad. Terminal branches tangential, forked, expanded horizontally, five to six times as long as the tube is broad; their number is usually five (more rarely four or six), and each is divided into two short, equal, divergent, secondary branches, armed at the distal end with a spathilla of five or six unequal recurved teeth.
Dimensions.—Length of the tubes 1.0 to 1.5, breadth 0.01 to 0.02; branches 0.05 to 0.08.
Habitat.—North Pacific, Stations 244 to 252, depth 2050 to 3050 fathoms.
7. Auloceros spathillaster, n. sp. (Pl. [102], fig. 12).
Radial tubes club-shaped or nearly cylindrical, straight, often thickened towards the distal end. Terminal branches ascending, three to six, usually four, partly simple, partly forked, slightly curved. The branches are from twice to three times as long as the tube is broad, and much thinner; at the distal end they are armed with a spathilla of five or six recurved teeth.