Page:Scientific results HMS Challenger vol 18 part 1.djvu/551

Rh to eight times as broad as the bars. Minor axis of the inner cavity about six times as large as the thickness of the spongy wall. Proportion of both axes = 4 : 1.

Dimensions.—Length of the shell 0.24, breadth 0.06.

Habitat.—South Pacific, Station 300, surface.

Definition.— with ellipsoidal or cylindrical (sometimes three-jointed) shell, of solid spongy framework, without internal cavity and without latticed medullary shell. Polar spines and outer lattice-mantle absent.

The genus Spongurus was founded by me in 1862 for the common cosmopolitan Spongurus cylindricus, a massive spongy cylinder with radial spines. I enlarge here the conception of the genus, in receiving also ellipsoidal, massive spongy, with or without radial spines. Sometimes the cylindrical shell is more or less distinctly three-jointed, with two annular strictures, as also in the following and nearly allied genus.

Definition.—Spongy framework everywhere of the same structure; surface smooth or rough, but without radial spines.

1. Spongurus stuparius, n. sp.

Shell ellipsoidal, one and a half times as long as broad, with nearly smooth surface. Spongy framework everywhere of equal structure, with small meshes, four to six times as broad as the bars.

Dimensions.—Length of the shell (or major axis) 0.2, breadth of it (or minor axis) 0.14.

Habitat.—South Pacific, Station 295, depth 1500 fathoms.

2. Spongurus stypticus, n. sp.

Shell ellipsoidal, twice as long as broad, with thorny surface. Spongy framework everywhere of equal structure, with large meshes, ten to twenty times as broad as the bars.

Dimensions.—Length of the shell 0.3, breadth 0.15.

Habitat.—Pacific, central area, Station 274, depth 2750 fathoms.

3. Spongurus phalanga, Haeckel.

Spongurus cylindricus, Stöhr, 1880, Palæontogr., vol. xxvi. p. 119, Taf. vii. fig. 3.

Shell nearly cylindrical, five times as long as broad, with thorny surface. Spongy framework compact, everywhere of equal structure, with small meshes, scarcely broader than the bars.