Dimensions.—Diameter of the shell 0.24, length of the spines 0.12.
Habitat.—Central Pacific, Station 271, depth 2425 fathoms.
3. Circoporus characeus, n. sp.
Shell spherical, covered with a delicate network of irregular polygonal plates. Six radial spines longer than the diameter of the shell, cylindrical, covered with numerous curved bristles, each with eight pores at the base surrounded by a circle of long bristles. Apex of each spine with a trident or fuscina, similar to that of the following species. Similar to an antheridium of Chara.
Dimensions.—Diameter of the shell 0.32, length of the spines 0.4.
Habitat.—South Pacific, Station 285, depth 2375 fathoms.
4. Circoporus sexfuscinus, n. sp. (Pl. [115], figs. 1-3).
Shell subregular, octahedral, with eight triangular, concave, somewhat unequal faces, which are covered with an extremely delicate network of small square dimples, and furrowed by radial crests arising from the bases of the spines (fig. 2). Six radial spines about as long as the diameter of the shell, four-sided, prismatic, with rounded edges; each in the basal half with a verticil of four crossed, curved bristles (fig. 1), sometimes with two verticils (fig. 2); on the distal apex inflated, armed with a trident or fuscina. Around the base of each spine four crossed elliptical pores. Mouth cruciform, with four small teeth (fig. 1).
Dimensions.—Diameter of the shell 0.2 to 0.25, length of the spines 0.2 to 0.25.
Habitat.—Tropical Atlantic, Station 348, depth 2450 fathoms.