5. Litholophus ligurinus, Haeckel.
Spines of variable number, from eleven to twenty, commonly twelve to sixteen, four-sided prismatic, with smooth thin edges, of equal breadth in their whole length or a little thinner towards the proximal end.
Dimensions.—Length of the spines 0.3, breadth 0.005.
Habitat.—Mediterranean (Nice); Central Pacific, Station 274, surface.
6. Litholophus rhipidium, Haeckel.
Spines of variable number, from eleven to twenty, commonly twelve to sixteen, four-sided prismatic, with distantly denticulated edges, of equal breadth in their whole length or a little thinner towards both ends.
Dimensions.—Length of the spines 0.3, breadth 0.006.
Habitat.—Mediterranean (Messina); North Atlantic, Station 352, surface.
Subgenus 3. Litholophonium, Haeckel.
Definition.—Number of the radial spines twenty (or more?).
7. Litholophus fasciculus, n. sp.
Spines constantly (?) twenty, four-sided prismatic, with smooth prominent edges, nearly of equal breadth throughout their whole length.
Dimensions.—Length of the spines 0.3 to 0.5, breadth 0.008.
Habitat.—South Pacific, Station 291, surface.
8. Litholophus penicillus, n. sp.
Spines constantly twenty (or more?), four-sided prismatic, with distantly denticulated edges, gradually thickened from the small pyramidal base to the middle part, of equal breadth in the distal half.
Dimensions.—Length of the spines 0.3 to 0.4, breadth 0.005 to 0.007.
Habitat.—North Pacific, Station 252, surface.
Family XXXV. Chiastolida, Haeckel.
Acanthochiasmida, Haeckel, 1862, Monogr. d. Radiol., p. 402.
Definition.—Acantharia with a variable number of simple radial spines, which are grown together in pairs (two opposite spines of each pair representing together a single diametral spine). Diametral spines crossed loosely in the centre of the spherical or irregular roundish central capsule. No lattice-shell.
