Shell slender, campanulate. Length of the three joints = 1 : 3 : 2, breadth = 1 : 4 : 4. Cephalis subspherical, with two divergent horns; the occipital of the same length and forked, the frontal shorter and simple. Thorax campanulate, with six to eight transverse rows of double-edged roundish pores of increasing size. Abdomen cylindrical, with three transverse rows of large polygonal pores, and a terminal row of very small square pores. Lumbar and terminal coronals of similar shape, each with twenty to thirty short divergent feet.
Dimensions.—Length of the three joints, a 0.02, b 0.06, c 0.04; breadth, a 0.025, b 0.08, c 0.08.
Habitat.—Central Pacific, Station 271, depth 2425 fathoms.
2. Diplocyclas bicincta, n. sp.
Shell campanulate, in general of the same form as, and similar fenestration to, the preceding species but not so slender, and with different proportions. Length of the three joints = 1 : 4 : 2, breadth = 2 : 5 : 5. Cephalis hemispherical, with a single, conical, simple horn. Pores of the thorax hexagonal, of increasing size (in eight to ten transverse rows). Abdomen with smaller square pores (in four to six rows). The two coronals of the same shape as in Pl. [59], fig. 8.
Dimensions.—Length of the three joints, a 0.02, b 0.08, c 0.04; breadth, a 0.04, b 0.1, c 0.1.
Habitat.—North Pacific, Station 253, depth 3125 fathoms.
3. Diplocyclas bizonalis, n. sp.
Shell subconical, with indistinct collar and distinct lumbar stricture. Length of the three joints = 1 : 2 : 3, breadth = 1 : 3 : 4. Cephalis hemispherical, with two divergent conical horns of equal size. Thorax conical, with small, irregular, double-edged pores, and a terminal corona of about nine very large pores. Abdomen truncate, conical, with three to four transverse rows of roundish, quadrangular, very large pores. Lumbar and terminal coronals of similar shape, each with twelve to fifteen triangular divergent feet.
Dimensions.—Length of the three joints, a 0.02, b 0.04, c 0.06; breadth, a 0.02, b 0.06, c 0.08.