Dimensions.—Length of the shell 0.24, breadth 0.05.
Habitat.—Pacific, central area, Station 268, depth 2600 fathoms; fossil in the Tertiary rocks of Sicily, Stöhr.
Subgenus 2. Spongurella, Haeckel.
Definition.—Spongy framework everywhere of the same structure; surface armed with radial spines.
4. Spongurus asper, Haeckel.
Shell ellipsoidal, one and a third times as long as broad, with thorny surface and twenty symmetrically disposed, thin, bristle-shaped, radial spines, about as long as the shell. Spongy framework everywhere of the same structure, very compact, with small meshes, three to four times as broad as the bars.
Dimensions.—Length of the shell 0.11, breadth 0.08.
Habitat.—Mediterranean, Ligurian coast (J. Müller), Portofino (Haeckel).
5. Spongurus cylindricus, Haeckel.
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.
