Page:Scientific results HMS Challenger vol 18 part 2.djvu/826

1702 4. Haeckeliana murrayana, Haeckel.

Challengeria sp., John Murray, 1876, Proc. Roy. Soc., vol. xxiv, pl. xxiv. fig. 6.

Shell with twenty to twenty-five coronets, the majority of which have five pores (more rarely four or six). Coronets of about the same breadth as their intervals, and twice as broad as the by-spines. Dimples subcircular, of about the same breadth as the pores. Radial main-spines about as long as the radius.

Dimensions.—Diameter of the shell 0.35 to 0.4, of the coronets 0.06 to 0.07.

Habitat.—Central Pacific, Stations 271 to 274, depth 2350 to 2750 fathoms.

5. Haeckeliana goetheana, n. sp. (Pl. 114, fig. 3).

Shell with sixteen to twenty coronets, the majority of which have four pores (more rarely five and very rarely six). Coronets smaller than their intervals. By-spines very short or rudimentary. Dimples subcircular, half as broad as the pores. Radial main-spines shorter than the radius.

Dimensions.—Diameter of the shell 0.25 to 0.3, of the coronets 0.04 to 0.05.

Habitat.—North Pacific (south of Japan), Station 231, depth 2250 fathoms.

6. Haeckeliana darwiniana, n. sp. (Pl. 114, figs. 1, 2).

Shell with twenty-six to thirty-two coronets, the majority of which have five pores (rarely four or six). Coronets smaller than their intervals and than the length of the by-spines. Dimples subcircular, half as broad as the pores, Radial main-spines longer than the radius.

Dimensions.—Diameter of the shell 0.30 to 0.42, of the coronets 0.07 to 0.08.

Habitat.—North Pacific (east of Japan), Stations 241 to 245, depth 2300 to 2900 fathoms.

Definition.— with an ovate, spindle-shaped, or nearly spherical shell exhibiting a peculiar solid porcellanous structure; with a few radial pores around the base of the hollow tubules, which are symmetrically arranged around the main axis and the mouth. Surface of the shell smooth or spiny, not tabulate nor panelled. Central capsule excentric, placed in the aboral half of the shell-cavity.

The, and the preceding closely allied family, the Circoporida, represent together a peculiar small group, which differs from the other in the singular porcellanous structure of the shell-wall, and may be called ; their hollow radial spines are distinguished by peculiar basal pores, forming a circle around their base. The shell of the Tuscarorida is monaxonian, ovate, spindle-shaped