Page:Scientific results HMS Challenger vol 18 part 1.djvu/431

Rh hexagon-corner arises a short bristle-shaped spine, twice as long as the tube, one-third as long as the radius. (Very similar to Ethmosphæra conulosa, Pl. 12, fig. 5, but differs in the possession of radial spines.)

Dimensions.—Diameter of the shell 0.2, pores 0.012, bars 0.006; length of the spines 0.04, of the tubes 0.02.

Habitat.—North Pacific, Station 253, surface.

3. Coscinomma macrosiphon, n. sp.

Pores regular, circular, without hexagonal frames, of the same breadth as the bars, prolonged on the outside of the shell into a long cylindrical tube, half as long as the radius (eight to nine pores on the radius); between them bristle-shaped, at the base conical, radial spines of double length.

Dimensions.—Diameter of the shell 0.16, pores and bars 0.008; length of the spines 0.08, of the tubes 0.04.

Habitat.—Central Pacific, Station 274, surface.

Definition.—Pores prolonged into internal tubes on the inside of the shell.

4. Coscinomma endosiphon, n. sp.

Pores regular, circular, hexagonally framed, twice as broad as the bars (fourteen to sixteen on the radius), prolonged on the inside of the shell into a short truncated cylindrical tube. In each hexagon-corner arises a thin, bristle-shaped, radial spine with pyramidal base, half as long as the radius, twice as long as the tube.

Dimensions.—Diameter of the shell 0.25, pores 0.012, bars 0.006; length of the spines 0.066, of the tubes 0.03.

Habitat.—South Pacific, Station 288, surface.

Definition.— with one simple lattice-sphere, covered with branched radial spines (the stem of the spine never forked).

The genus Cladococcus, together with the following Elaphococcus, is distinguished from the other Coscinommida by the ramification of the radial spines covering the surface of the simple hollow lattice-sphere. In Cladococcus each spine sends out three or more lateral branches, which are either simple or again ramified; but the stem of the spine itself is not forked, as in Elaphococcus.