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.