Page:Scientific results HMS Challenger vol 18 part 1.djvu/715

Rh spines short, pyramidal, about as long as the breadth of one ring. Margin between them ciliated, with thin radial bristles.

Dimensions.—Diameter of the disk (with four rings) 0.13; breadth of each ring 0.015; pores 0.0025.

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

3. Staurodictya elegans, n. sp. (Pl. 42, fig. 1).

All rings of the disk concentric, circular, or roundish, of increasing breadth towards the margin; the fifth ring twice as broad as the first. Pores irregular, roundish, two to three on the breadth of each ring. Four marginal spines very large, conical, with a thin pedicle at the base, cancellated by ten to twelve deep furrows, about as long as the radius of the disk and three times as long as broad at the base (above the pedicle). Margin between them ciliated, with numerous short radial spines.

Dimensions.—Diameter of the disk (with six rings) 0.14; breadth of the inner rings 0.006, of the outer 0.012; pores 0.002 to 0.008.

Habitat.—Pacific, central area, Station 272, depth 2600 fathoms.

4. Staurodictya quadrispina, Haeckel.

Stylodictya quadrispina, Haeckel, 1862, Monogr. d. Radiol., p. 496, Taf. xxix. fig. 4.

All rings of the disk concentric, circular, of increasing breadth towards the margin; the fourth ring twice as broad as the second. Pores irregular, roundish, two to three on the breadth of each ring. Four marginal spines short and thin, conical, about as long as the breadth of one ring. Margin between them smooth.

Dimensions.—Diameter of the disk (with six rings) 0.12; breadth of the inner rings 0.006, of the outer rings 0.012; pores 0.001 to 0.006.

Habitat.—Mediterranean, Atlantic (Canary Islands), surface.

Definition.—All rings of the disk or a part of them not concentric, spirally convoluted; spiral line simple or double, sometimes half or irregular, interrupted.

5. Staurodictya cruciata, n. sp. (Pl. 42, figs. 4, 5).

All rings of the disk nearly of the same breadth, not concentric, half-spiral, interrupted by four zigzag-shaped radial beams crossed in two diameters perpendicular one to another. The quarter ring of each quadrant halving both neighbouring quarters. Pores irregular, roundish, two on the breadth of each ring. Pores of the outermost (eighth) ring much smaller than the others. Four marginal spines cylindrical or nearly spindle-shaped, thick, about as long as the radius of the disk. Margin between them smooth.

Dimensions.—Diameter of the disk (with eight rings) 0.2; breadth of each ring 0.011; pores 0.004.

Habitat.—Pacific, central area, Station 265, depth 2900 fathoms.