The genus Cubosphæra may be regarded as a form of Styptosphæra, which develops six radial spines, opposite in pairs in the three dimensive axes. The solid spongy framework of the shell assumes the outer form either of a sphere, or of a regular octahedron.
1. Cubaxonium spongiosum, n. sp.
Spongy shell spherical, composed of a very dense spongy framework of nearly uniform structure; the meshes three to four times as broad as the bars; surface almost smooth. Six spines cylindrical, twice to three times as long as the diameter of the spongy sphere, about as broad as one half mesh.
Dimensions.—Diameter of the sphere 0.2, meshes 0.006 to 0.008, bars 0.002; length of the spines 0.4 to 0.5, breadth 0.004.
Habitat.—South Pacific, Station 288, surface.
2. Cubaxonium octahedrum, n. sp.
Spongy shell octahedral, composed of a loose spongy framework of nearly uniform structure; the meshes ten to twelve times as broad as the bars; surface thorny. Six spines three-sided pyramidal, longer than the diameter of the octahedron, arising from its six corners, as broad at the base as one mesh.
Dimensions.—Diameter of the shell 0.15, meshes 0.01 to 0.012, bars 0.001; length of the spines 0.2, basal breadth 0.01.
Habitat.—South Pacific, Station 300, surface.