Phacoid shell four times as broad as the medullary shell, surrounded by one single ring, which is divided by forty radial beams into equal chambers. Pores regular, circular; two on the breadth of the ring, six on the radius of the phacoid shell. Margin with forty short, conical spines, the prolongations of the inner radial beams, twice as long as the breadth of the ring.

Dimensions.—Diameter of the disk 0.13, of the phacoid shell 0.1, of the medullary shell 0.025.

Habitat.—South Atlantic, Station 332, depth 2200 fathoms.

4. Astrocyclia arachnia, n. sp.

Phacoid shell twice as broad as the medullary shell, surrounded by four to six rings of equal breadth, which are divided by twelve to twenty radial beams into broad chambers. Pores regular, circular; two on the breadth of each ring, eight on the radius of the phacoid shell. Margin with twelve to twenty very long and thin, bristle-shaped, radial spines, the prolongations of the inner beams, longer than the diameter of the disk. (Resembles Stylodictya arachnia, but differs in the possession of a phacoid shell.)

Dimensions.—Diameter of the disk (with six rings) 0.22, of the phacoid shell 0.09, of the medullary shell 0.045.

Habitat.—North Atlantic, Canary Islands.

5. Astrocyclia heterocycla, n. sp. (Pl. [36], fig. 8). Phacoid shell two and a half times as broad as the medullary shell, surrounded by three rings of unequal breadth, the first ring as broad as the second and third together. They are divided by fifty to sixty piercing radial beams into chambers, which are square in the second and third rings, and half as large as in the first. The radial beams are alternately thicker and thinner, prolonged into short marginal spines. Pores subregular, circular; eight on the radius of the phacoid shell, two on the breadth of the first ring, a single one on each chamber of the second and third rings.

Dimensions.—Diameter of the disk (with three rings) 0.2, of the phacoid shell 0.12, of the medullary shell 0.05.

Habitat.—Equatorial Atlantic, Station 348, depth (2450) fathoms; also fossil in Barbados.