Disk hexagonal, four times as broad as the hexagonal central chamber. Three arm-chambers triangular, at the base half as broad as at the truncated distal end, about the same size as the three heart-shaped gates. On the six corners of the margin (which forms a regular hexagon) are six pyramidal radial spines, as prolongations of the arm-edges.
Dimensions.—Diameter of the disk 0.05, of the gates 0.02.
Habitat.—Indian Ocean, Ceylon, surface, Haeckel.
5. Triopyle renigera, n. sp.
Disk hexagonal, five times as broad as the circular central chamber. Three arm-chambers trapezoidal, at the base one-third, at the distal end two-thirds as broad as the three kidney-shaped gates. On the six corners of the margin (which forms an irregular hexagon) six conical radial spines, as prolongations of the arm-edges.
Dimensions.—Diameter of the disk 0.06, of the gates 0.02.
Habitat.—South Pacific, Station 295, depth 1500 fathoms.
6. Triopyle spinigera, n. sp.
Disk roundish, triangular, four times as broad as the triangular central chamber, which is armed with three radial spines between the arms. Arm-chambers club-shaped, at the narrow base one-fourth, at the distal end half as broad as the square gates. On the margin twelve large conical spines, two opposite on each face of the distal end of each arm-edge. Three smaller radial spines on the three corners of the girdle (in the same interradial meridian planes as the three spines of the central chamber). Compare Triodiscus spinosus.
Dimensions.—Diameter of the disk 0.05, of the gates 0.02.