Dimensions.—Diameter of the cube 0.05; thickness of the bars 0.008.
Habitat.—Tropical Pacific, Station 224, depth 1850 fathoms.
2. Lithocubus octacanthus, n. sp.
The twelve rods of the cubical shell are slightly curved, convex, smooth, as in the similar preceding species. It differs from that in the development of eight slender radial spines, arising from the eight corners of the geometrical cube, from two to three times as long as its diameter, and lying opposite in pairs in its diagonals.
Dimensions.—Diameter of the cube 0.06; length of the spines 0.15.
Habitat.—North Atlantic, Canary Islands, surface.
3. Lithocubus vinculatus, Haeckel.
Acanthodesmia vinculata, J. Müller, 1856 (partim), Abhandl. d. k. Akad. d. Wiss. Berlin, Taf. i. fig. 7 (not 4-6).
The twelve rods of the cubical shell are curved and armed with scattered, simple, short spines. The figure 7 of Johannes Müller (loc. cit.) corresponds exactly to the Mediterranean form observed by me at Portofino, and is quite different from his true Acanthodesmia vinculata (loc. cit., figs. 4-6), so that I have no doubt he did observe these two different species (compare above, p. [975]).
Dimensions.—Diameter of the cube 0.07; length of the spines 0.02.