Dimensions.—Length of the middle rod of the spicula 0.02 to 0.06, of its shanks 0.01 to 0.05.
Habitat.—Cosmopolitan, common in nearly all warmer seas, Mediterranean, Atlantic, Indian Ocean, Pacific; surface.
10. Sphærozoum armatum, n. sp. (Pl. [4], fig. 9).
Spicula all geminate-triradiate, with a stout and short middle rod and three arborescent shanks on each end of it. Shanks longer than the middle rod, very stout, straight, pine-shaped, with six to twelve irregular, spinulated, lateral branches.
Dimensions.—Diameter of the central capsules 0.04 to 0.08, length of the middle rod of the spicula 0.02 to 0.03, of its shanks 0.05 to 0.08.
Habitat.—North Pacific, Japan, Station 239, surface.
11. Sphærozoum alveolatum, n. sp. (Pl. [4], figs. 2, 3).
Spicula all together geminate-triradiate, with a simple stout middle rod and three arborescent shanks on each end of it. Shanks more or less curved, slender, pine-shaped, with four to eight short, thorny lateral branches. In all cœnobia of this remarkable species the central capsules are enclosed in large thick-walled alveoles (of three times their breadth), and in each alveole is placed besides the capsule one single very large spiculum, whilst the others are much smaller (fig. 3). All the alveolated capsules are placed in one single stratum on the surface of the jelly-like spherical cœnobium, comparable to the blastoderm-cells of a blastula.
Dimensions.—Diameter of the central capsules 0.08 to 0.1, of the alveoles 0.2 to 0.4, length of the spicula 0.1 to 0.3.
Habitat.—South Pacific (Juan Fernandez), Station 300, surface.