Spicula all (or nearly all) tetraradiate, with four thorny, straight, pointed shanks, radiating from one common point. (Intermingled with these are often some few, thorny, triradiate spicula.) On the inside of the capsule a layer of large oil-globules as in Thalassoplancta, Pl. [2], fig. 2.
Dimensions.—Diameter of the central capsule 0.2, of the nucleus 0.08, of the calymma 0.8.
Habitat.—South Pacific, Station 288, surface.
Subgenus 2. Lampoxanthomma, Haeckel.
Definition.—Spicula all (or nearly all) of one kind, geminate-radiate, with a simple middle rod and two to four diverging shanks on each end of it.
2. Lampoxanthium punctatum, n. sp.
Spicula all geminate-triradiate, thorny, of the same form as in the common Sphærozoum punctatum, of which this species is the large solitary representative. The spicula are aggregated in a very condensed layer on the surface of the large calymma.
Dimensions.—Diameter of the capsule 0.8, of the nucleus 0.6, of the calymma 2.0.
Habitat.—North Pacific, Station 248, surface.
3. Lampoxanthium octoceras, n. sp.