Spicula all geminate-quadriradiate, with a very short simple middle rod and four very long divergent shanks on both ends of it; the shanks are smooth, five to ten times as long as the middle rod, irregularly bent and curved. (Differs from the similar Thalassoxanthium octoceras, Pl. [2], fig. 6, by slender, more curved shanks, and by the voluminous calymma, there entirely wanting.)
Dimensions.—Diameter of the capsule 0.5, of the nucleus 0.2, of the calymma 3.0.
Habitat.—South Atlantic, Station 331, surface.
Subgenus 3. Lampoxanthura, Haeckel.
Definition.—Spicula of two or three different kinds, simple, radiate, and geminate-radiate mixed.
4. Lampoxanthium pandora, n. sp. (Pl. [2], fig. 1).
Spicula mixed, of three different kinds—simple, radiate and geminate-radiate; all three kinds partly smooth, partly thorny. The simple needles short, thin spindle-shaped, often curved. The radiate spicula commonly with three or four, rarely five or six, unequal rays, straight or curved. The radiate-geminate spicula commonly with three, rarely four, shanks on each end, often different on both ends of the middle rod. The size, number, and form of the irregular spicula are here quite as variable as in the social Rhaphidozoum pandora, of which it is the solitary representative. The wall of the large central capsule is very thick, with evident pore-canals, separated by a clear interval from the coagulated and vacuolated endoplasm, which contains no oil-globules. Nucleus with numerous nucleoli.
Dimensions.—Diameter of the central capsule 0.5 to 0.6, of the nucleus 0.1 to 0.2, of the calymma 2 to 4 mm.
Habitat.—North Pacific, Station 244, surface.