Habitat.—South Pacific, Station 295, depth 1500 fathoms.

4. Tricolocapsa decandollei, n. sp. (Pl. [66], fig. 4).

Shell subovate, with two sharp strictures. Length of the three joints = 2 : 2 : 2, breadth = 3 : 4 : 3.5. Cephalis campanulate. Thorax broader, ring-shaped. Abdomen inversely hemispherical. All three joints of the same length, thick-walled, with the same regular and peculiar reticulation, the small circular pores being surrounded by square, elevated frames.

Dimensions.—Length of the three joints, a 0.07, b 0.07, c 0.07; breadth, a 0.10, b 0.14, c 0.12.

Habitat.—Western Tropical Pacific, Station 225, depth 4475 fathoms.

Subgenus 2. Tricolocapsium, Haeckel.

Definition.—Thorax much smaller than the abdomen.

5. Tricolocapsa brownii, n. sp.

Shell ovate, very thick-walled, with two indistinct strictures. Length of the three joints = 2 : 4 : 7, breadth = 3 : 7 : 10. Cephalis flat, hemispherical. Thorax truncate, conical. Abdomen inflated, inversely hemispherical. Pores regular, circular, of the same breadth as the bars, hexagonally-framed, twice as large in the abdomen as in the thorax. Basal pole rounded.

Dimensions.—Length of the three joints, a 0.02, b 0.04, c 0.07; breadth, a 0.03, b 0.07, c 0.1.