Page:Scientific results HMS Challenger vol 18 part 1.djvu/1075

Rh Dimensions.—Major axis of the shell 0.1, minor 0.08; length of the spines 0.06, of their sheaths 0.04.

Habitat.—Arctic Ocean, Greenland, Koch, surface.

4. Coleaspis occulta, n. sp.

All twenty spines of nearly equal size and form, quite concealed in their long cylindrical sheaths, which are somewhat longer than the radius of the shell, and armed on the truncated mouth with acute simple teeth; each sheath deeply sulcated, apparently resulting from the concrescence of numerous parallel leaf-shaped by-spines. Small shell very dark and thick-walled, quite opaque.

Dimensions.—Major axis of the shell 0.08, minor 0.06; length of the spines and their sheaths 0.05 to 0.06.

Habitat.—Antarctic Ocean (off Kerguelen), Station 159, surface.

Definition.—Both equatorial spines of the hydrotomical axis much larger and of peculiar form, different from the eighteen other spines.

5. Coleaspis amphilonche, n. sp.

Both equatorial spines of the hydrotomical axis much longer than the eighteen others, and of very different form; one and a half times as long as the diameter of the shell, prismatic, with six prominent edges, pyramidal at the distal point. The eighteen other spines triangular, compressed, two-edged, scarcely as long as the radius of the thick-walled shell. Pores of the shell irregular polygonal, separated by ciliated crests, which bear simple by-spines (one-third as long as the radius).

Dimensions.—Major axis of the shell 0.15, minor 0.12; length of the two larger spines 0.22, of the eighteen smaller 0.06 to 0.08; basal breadth of the former 0.03, of the latter 0.008.

Habitat.—South Atlantic, Station 341, surface.

6. Coleaspis hydrotomica, n. sp. (Pl. 140, fig. 14).

Both equatorial spines of the hydrotomical axis much larger than the eighteen others, and of very different form; about as long as the diameter of the shell, in the basal half four-sided pyramidal, with four thick prominent edges, in the middle part constricted, in the distal half lanceolate, two-edged. Both equatorial spines of the geotomical axis of similar form, but much smaller, scarcely one-third as long. The sixteen other spines sword-like, thin, two-edged, about as long as the radius of the thick-walled shell. Pores of the shell irregular roundish, separated by high dentated crests, which bears zigzag by-spines (half as long as the radius).

Dimensions.—Major axis of the shell 0.12, minor axis 0.1; length of the two larger spines 0.11, of the eighteen others 0.04 to 0.06; basal breadth of the former 0.04, of the latter 0.01.

Habitat.—Cape of Good Hope, Station 143, surface.