Page:Scientific results HMS Challenger vol 18 part 1.djvu/480

272 Dimensions.—Diameter of the sphere 0.16; length of the main spines 0.11, of the by-spines 0.03.

Habitat.—Fossil in the Alpine Jura, Schafberg near Salzburg (Dunikowski).

7. Spongiomma asteroides, n. sp.

Spongy framework in the central part of the sphere much denser and darker than in the peripheral part. Sixty to eighty cylindro-conical main spines, as long as the radius, between them are numerous straight, bristle-shaped by-spines half that length.

Dimensions.—Diameter of the sphere 0.28; length of the main spines 0.16, of the by-spines 0.08.

Habitat.—South Atlantic, Station 325, surface.

Definition.— with solid spongy sphere, without latticed medullary shell, with numerous branched radial spines.

The genus Spongodrymus differs from the preceding Spongiomma in the ramification of the numerous radial spines, covering the surface of the solid spongy sphere.

1. Spongodrymus elaphococcus, n. sp. (Pl. 18, fig. 9).

Spongy framework of the solid sphere equal throughout, on the surface arising in the form of very numerous (sixty to eighty or more) spongy cones with rather rhomboidal meshes. Each cone is prolonged into a very thin, irregularly curved radial spine, which is twice as long as the shell diameter, simple in the proximal half, branched like a tree in the distal half; each arborescent spine has from sixteen to thirty-two terminal branches, which fall in one spherical face. The branches of neighbouring spines are partly connected by anastomoses, so that they begin to form an outer spherical shell (cortical shell) with a looser spongy framework.

Dimensions.—Diameter of the whole spherical skeleton (sphere formed by the distal ends of the dichotomous branches) 0.9, of the inner solid spongy sphere 0.02.

Habitat.—Tropical Atlantic, Station 349, surface.

2. Spongodrymus abietinus, n. sp.

Spongy framework denser and darker in the central part of the sphere than in the peripheral part, with rather coarse meshes and thick bars. From the surface arise very numerous (sixty to eighty) stout, radial branches, as long as the shell radius, branched like a pine tree (with six to twelve ramified branches). Similar in structure to Cromyodrymus abietinus (Pl. 30, fig. 6), but with a quite irregular spongy texture in the central sphere.

Dimensions.—Diameter of the sphere 0.3; length of the spines 0.015.

Habitat.—Central Pacific, Station 272, surface.