Dimensions.—Length of the central capsules 0.6 to 1.2 mm., sometimes 3 to 6 mm.; breadth 0.12.

Habitat.—Tropical Atlantic, near the west coast of Africa, Station 349, Canary Islands, surface.

Subgenus 4. Collodiscus, Haeckel.

Definition.—Form of the central capsules discoidal or lenticular, with one shortened axis.

9. Collozoum coeruleum, Haeckel.

Collozoum coeruleum, Haeckel, 1862, Monogr. d. Radiol., p. 523, Taf. xxxii. figs. 6-8.

Collodiscus coeruleus, Haeckel, 1882, Manuscript.

Central capsule lenticular or discoidal, flattened, blue coloured, with one single oil-globule in the centre. Protoplasm containing numerous crystals and dark blue pigment-granules. Membrane very thick, double-edged. (Whilst at Messina in 1859 I found this form not constantly discoidal, in 1867 in the Canary Islands I observed it constantly lenticular.)

Dimensions.—Breadth of the central capsules 0.1 to 0.15, height 0.04 to 0.08.

Habitat.—Mediterranean (Messina), Atlantic (Canary Islands), surface.