Page:Scientific results HMS Challenger vol 18 part 1.djvu/368

160

Definition.—Pores of the cortical shell regular, and of nearly equal size and similar form; surface covered with by-spines or thorns.

6. Staurolonche straussii, n. sp.

Cortical shell thin walled, four times as broad as the medullary shell, and covered with numerous bristle-shaped by-spines, half as long as the radius. Pores regular, circular, hexagonally framed, twice as broad as the bars; six to eight on the radius. On each hexagonal frame twelve by-spines (six at the corners, six in the middle between them). Four main spines six-sided pyramidal, about as long as the radius, twice as broad as one mesh.

Dimensions.—Diameter of the outer shell 0.16, inner 0.04; cortical pores 0.016, bars 0.008; length of the spines 0.1.

Habitat.—West Tropical Pacific, Station 225, depth 4475 fathoms.

7. Staurolonche feuerbachii, n. sp.

Cortical shell thick walled, five times as broad as the medullary shell, and covered with short conical by-spines. Pores regular, circular, twice as broad as the bars; twenty to twenty-two on the quadrant. Four main spines three-sided prismatic, with pyramidal apex, two to three times as long as the radius, twice as broad as one mesh.

Dimensions.—Diameter of the outer shell 0.27, of the inner 0.055; cortical pores 0.008, bars 0.004; length of the spines 0.3 to 0.4.

Habitat.—Fossil in Barbados.

8. Staurolonche moleschottii, n. sp.

Cortical shell thick walled, three times as broad as the medullary shell, and covered with short conical by-spines. Pores regular, circular, of the same breadth as the bars; fourteen to sixteen on the quadrant. Four main spines conical, as long as the radius, three times as broad at the base as one mesh.

Dimensions.—Diameter of the outer shell 0.15, inner 0.05; cortical pores and bars 0.004; length of the spines 0.08.

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

Definition.—Pores of the cortical shell irregular, of different size or form; surface smooth.

9. Staurolonche holbachii, n. sp.

Cortical shell thin walled, with smooth surface, three times as broad as the medullary shell. Pores irregular, polygonal, twice to four times as broad as the bars. Four main spines three-sided prismatic, longer than the shell diameter.