9. Thalassoxanthium punctatum, n. sp.
Spicula all geminate-triradiate, composed of a simple middle rod and of three diverging shanks on each end of it; the shanks are thorny with small spinules and shorter than the axial rod, very similar to the common Sphærozoum punctatum. Central capsule dark, with numerous (twenty to thirty) oil-globules on the inside of the membrane, three times as broad as the nucleus.
Dimensions.—Diameter of the capsule 0.3, of the nucleus 0.1, length of the spicula 0.05 to 0.2.
Habitat.—Central Pacific, Station 274, surface.
10. Thalassoxanthium octoceras, n. sp. (Pl. [2], fig. 6).
Spicula all geminate-quadriradiate, composed of a simple short middle rod and of four diverging shanks on each end of it; the shanks are quite smooth, irregularly curved or bent, and four to eight times as long as the middle rod. Central capsule dark, filled with pigment-granules, without oil-globules, four times as large as the nucleus.
Dimensions.—Diameter of the capsule 0.5, of the nucleus 0.12, length of the spicula 0.2 to 0.4.
Habitat.—Indian Ocean, Madagascar, Rabbe.
Genus 9. Physematium,[[17]] Meyen, 1834, Nova Acta Acad. Nat. Curios., vol. xvi., Suppl., p. 286 (p. 162).
Definition.—Thalassosphærida with large numerous alveoles within the central capsule (not in the calymma), and with numerous simple, needle-shaped spicula in the calymma.