Spongurus cylindricus, Haeckel, 1862, Monogr. d. Radiol., p. 465, Taf. xxvii. fig. 1.
Shell cylindrical, four to five times as long as broad, with nearly smooth surface, and twenty to thirty thin, bristle-shaped, radial spines, about half as long as the shell. Spongy framework everywhere of the same structure, very compact, with small meshes, scarcely broader than the bars.
Dimensions.—Length of the shell 0.2, breadth 0.04 to 0.05.
Habitat.—Cosmopolitan; Mediterranean, Atlantic, and Pacific, surface.
6. Spongurus tricolus, n. sp.
Shell nearly cylindrical, with two slight annular transverse strictures; its middle part is somewhat broader. Surface thorny, with numerous (forty to sixty or more) short, thin, radial spines, not longer than the breadth of the shell. Spongy framework everywhere of the same structure, compact, with small meshes, twice to three times as broad as the bars.
Dimensions.—Length of the shell 0.24, breadth 0.04 to 0.06.
Habitat.—Pacific, central area, Station 272, 2600 fathoms.
Subgenus 3. Sponguroma, Haeckel.
Definition.—Spongy framework in the inner part of the shell very compact, in the outer part very loose; surface armed with radial spines.