1. Castanura tizardi, n. sp. (Pl. 113, fig. 4, 4a).
Pores regular, circular, without hexagonal frames, twice as broad as the bars. Bristles twice as long as one pore. Radial main-spines somewhat longer than the radius, straight, very stout, with irregular lateral branches, which are partly confluent. Mouth with six strong conical teeth.
Dimensions.—Diameter of the shell 0.6, of the pores 0.03.
Habitat.—Tropical Atlantic, Station 346, surface.
2. Castanura havergali, n. sp.
Pores regular, circular, hexagonally framed, as broad as the bars. Bristles three times as long as one pore. Radial main-spines as long as the shell-diameter, in the basal half simple, in the distal half with irregular, not confluent, lateral branches. Mouth with ten to twelve irregular, parallel, conical teeth of different sizes.
Dimensions.—Diameter of the shell 0.5, of the pores 0.045.
Habitat.—Indian Ocean, Madagascar (Rabbe), surface.
3. Castanura swirei, n. sp.
Pores regular, circular, hexagonally framed, as broad as the bars. Bristles half as long as the radius. Radial main-spines straight, longer than the shell-diameter; on the distal end with a few irregular, confluent, lateral branches. Mouth with six larger and six alternate smaller, parallel, conical teeth.
Dimensions.—Diameter of the shell 0.28, of the pores 0.015.
Habitat.—North Pacific, Station 253, surface.
4. Castanura carpenteri, n. sp.
Pores irregular, roundish, twice to four times as broad as the bars. Bristles about as long as the largest pores. Radial main-spines irregularly curved, longer than the shell-diameter, with inflated and fenestrated conical base; in the distal half irregularly branched, with simple, not confluent, lateral branches. Mouth with six to nine irregular, strong, conical teeth.
Dimensions.—Diameter of the shell 0.3, of the pores 0.012 to 0.025.
Habitat.—South Atlantic, Station 331, depth 1715 fathoms.
Circoporida, Haeckel, 1879, Sitzungsb. med.-nat. Gesellsch. Jena, Dec. 12, p. 5.
Definition.—Phæodaria with a spherical or polyhedral shell, exhibiting a peculiar solid porcellanous structure, with a stellate circle of radial pores around the base of the hollow radial spines. Mouth usually with teeth. Surface of the shell
