Dimensions.—Length of the three joints, a 0.02, b 0.04, c 0.24; breadth, a 0.03, b 0.07, c 0.1 to 0.14.
Habitat.—Central Pacific, Stations 265 to 269, depth 2550 to 2900 fathoms.
2. Cycladophora tetrapleura, n. sp.
Shell very similar to the preceding species, but differing in the following characters: Cephalis conical, with a horn of the same length. Thorax campanulate. Four ribs of the abdomen not parallel and vertical, but more or less divergent. Length of the three joints = 1 : 2 : 8, breadth = 1 : 2 : 4. Whole shell slender, pyramidal. Mouth square, four-lobed.
Dimensions.—Length of the three joints, a 0.03, b 0.06, c 0.24; breadth, a 0.03, b 0.06, c 0.12.
Habitat.—North Pacific, Station 241, depth 2300 fathoms.
3. Cycladophora lanterna, n. sp.
Shell very similar to the two preceding species, but differing in the following characters. Cephalis subspherical, with a thick, pyramidal horn of the same breadth, and three times the length. Thorax hemispherical, with circular, hexagonally-framed pores. Abdomen ovate, with four convex ribs, and twelve large holes, four superior smaller pentagonal, four intermediate very large, ovate, and four inferior, small, triangular holes. Mouth little constricted, nearly circular.
Dimensions.—Length of the three joints, a 0.025, b 0.05, c 0.22; breadth, a 0.025, b 0.08, c 0.11.
Habitat.—Tropical Atlantic, Station 347, depth 2250 fathoms.