Page:Scientific results HMS Challenger vol 18 part 1.djvu/284

76 17. Carposphæra maxima, n. sp.

Cortical shell thin walled, smooth, five times as broad as the medullary shell, with irregular roundish pores, of about the same breadth as the bars.

Dimensions.—Diameter of the outer shell 0.4, inner 0.08, pores and bars 0.004 to 0.008.

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

18. Carposphæra nodosa, n. sp. (Pl. 28, figs. 2, 2a).

Anthomma nodosum, Haeckel, 1879, Atlas, ''loc. cit.''

Cortical shell thick walled, covered with forty to fifty scattered pyramidal nodules, two and a half times as broad as the medullary shell, connected with it by very numerous thin radial beams. Outer and inner pores irregular roundish or polygonal, two to three times as broad as the bars. (This species in consequence of the cortical nodules may represent a peculiar genus, analogous to Conosphæra, called Anthomma.)

Dimensions.—Diameter of the outer shell 0.13, inner 0.05, inner and outer pores 0.008 to 0.012, bars 0.004.

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

Definition.— with two cortical (extracapsular) shells (without a medullary or intracapsular shell).

The genus Liosphæra agrees with the preceding Carposphæra in the possession of two concentric latticed spheres; but whilst in the latter genus the inner sphere is a medullary one (intracapsular), the outer a cortical shell (extracapsular), both connected by radial beams piercing the capsule-wall, here in Liosphæra the central capsule lies freely within the inner lattice shell and is not pierced by radial beams. Therefore both shells are here cortical shells, both separated by a distance, which is constantly much smaller than the radius of the inner shell; whereas in Carposphæra this distance is at least as large as that radius (commonly much larger). In Carposphæra the number of pores in both shells is never the same; in several species of Liosphæra this number is the same, each outer regular hexagonal pore exactly corresponding to an inner; the six corners of each connected by six short radial beams.

Definition.—Pores of both shells regular, in each shell all of nearly equal size and form.

1. Liosphæra hexagonia, n. sp. (Pl. 20, fig. 3).

Both shells with the same number of pores, exactly corresponding, about ten on the quadrant.