Habitat.—Cosmopolitan; Atlantic, Indian, Pacific; many Stations, surface, and at various depths.
4. Cœlodendrum bifurcum, n. sp.
Terminal branches regularly forked, with two equal, smooth, more or less curved fork-branches, diverging at acute angles; their end-knobs thin, with two slender, parallel, bristle-shaped teeth.
Dimensions.—Diameter of the skeleton 0.6 to 0.8, of the two central valves 0.1 to 0.15.
Habitat.—North Pacific, Stations 252 to 256, surface.
5. Cœlodendrum gracillimum, Haeckel.
Cœlodendrum gracillimum, Haeckel, 1862, Monogr. d. Radiol., p. 364, pl. xxxii. fig. 1.
Terminal branches regularly forked, with two equal, spinulate, curved fork-branches, diverging at obtuse angles and covered with numerous small thorns; their end-knobs cap-shaped, with a corona of six to eight small recurved teeth. In one specimen of this species (in 1859) I found entangled the fragments of Cœlographis gracillima, figured in Taf. xxxii. figs. 2, 3, loc. cit. I supposed at that time, erroneously, that the latter belonged to full-grown specimens of the former.
Dimensions.—Diameter of the skeleton 1 to 1.2, of the valves 0.15 to 0.2.
Habitat.—Mediterranean (Messina), surface.