Habitat.—Central Pacific, Station 273, surface.
4. Corocalyptra margarethæ, n. sp.
Shell nearly conical, hat-shaped, very similar to the preceding species, but with much more delicate hexagonal network, with thread-like bars. Length of the three joints = 1 : 7 : 2, breadth = 1 : 10 : 12. Cephalis hemispherical, with six bristle-shaped spines of half the length of the shell; three horns divergent upwards, and three alternating feet divergent downwards. Thorax nearly conical. Abdomen flatter.
Dimensions.—Length of the three joints, a 0.015, b 0.1, c 0.03; breadth, a 0.02, b 0.15, c 0.18.
Habitat.—North Pacific, Station 236, surface.
5. Corocalyptra ludovicæ, n. sp.
Shell flatly campanulate or hat-shaped. Length of the three joints = 1 : 4 : 3, breadth = 2 : 7 : 10. Cephalis hemispherical, with six bristle-shaped spines, about one-fourth to one-third as long as the shell; three horns diverging upwards, and three alternate feet diverging downwards. Thorax nearly conical. Abdomen much larger than in all preceding species, inflated, with convex, lateral outline; its mouth-edge curved inwards. The network is much finer than in the similar Corocalyptra emmæ (Pl. [59], fig. 4), and the abdomen is relatively twice as long and broad.
Dimensions.—Length of the three joints, a 0.02, b 0.08, c 0.06; breadth, a 0.04, b 0.14, c 0.2.
Habitat.—Central Pacific, Station 271, surface.