Page:Scientific results HMS Challenger vol 18 part 1.djvu/429

Rh Dimensions.—Diameter of the shell 0.12, pores 0.005 to 0.01, bars 0.003; length of the main spines 0.08, basal breadth 0.01.

Habitat.—South Atlantic, Station 325, surface.

14. Heliosphæra solaris, n. sp.

Shell thick walled, with irregular, roundish pores, about the same breadth as the bars; six to eight on the radius. Fifty to eighty main spines, conical, as long as the radius; by-spines very numerous, also conical, but only as large as one pore.

Dimensions.—Diameter of the shell 0.15, pores and bars 0.006 to 0.008; length of the main spines 0.08, basal breadth 0.012.

Habitat.—Central Pacific, Station 268, depth 2900 fathoms.

Definition.— with one simple latticed sphere, covered with radial spines having the form of hollow cones with porous walls.

The genus Conosphæra differs from Acanthosphæra in the peculiar formation of the radial spines, which are not simple solid sticks, but hollow cones with porous walls, as immediate elevations of the hollow sphere.

1. Conosphæra platyconus, n. sp.

Pores of the shell regular, circular, twice as broad as the bars; ten to twelve on the radius. Conical spines about sixty, regular, broader than they are high, with six to nine pores in the wall.

Dimensions.—Diameter of the shell 0.16, pores 0.008, bars 0.004; length of the spines 0.012, basal breadth 0.024.

Habitat.—Central Pacific, Station 272, depth 2600 fathoms.

2. Conosphæra orthoconus, n. sp. (Pl. 12, fig. 2).

Pores of the shell irregular, roundish, twice to three times as broad as the bars; fourteen to sixteen on the radius. Conical spines about forty, regular, higher than they are broad, as long as the radius, with sixteen to twenty pores in the wall.

Dimensions.—Diameter of the shell 0.2, pores 0.008 to 0.012, bars 0.004; length of the spines 0.05, basal breadth 0.03.

Habitat.—Central Pacific, Station 271, depth 2425 fathoms.