Page:Scientific results HMS Challenger vol 18 part 2.djvu/561

Rh 1. Stichopilium cortina, n. sp.

Shell ovate, with three sharp strictures. Length of the four joints = 2 : 6 : 3 : 4. Cephalis subspherical, with a slender pyramidal horn of twice the length. The three edges of the horn are prolonged into three strong divergent ribs, along the three first joints, and into three free conical lateral spines, directed downwards, on the end of the third joint. The fourth joint is subcylindrical; its circular, terminal mouth half as broad as the third joint, which is the broadest. Pores small, regular, hexagonal, with thin bars.

Dimensions.—Length of the shell (with four joints) 0.15, breadth 0.08. Length of the single joints, a 0.02, b 0.06, c 0.03, d 0.04.

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

2. Stichopilium costatum, n. sp.

Shell conical, or nearly pyramidal, with three distinct strictures. Length of the four joints = 3 : 5 : 8 : 4. Cephalis subconical, with a stout pyramidal horn of the same length. Thorax campanulate, with six longitudinal ribs, from three of which in the middle arise three horizontal, conical, free spines or wings, about as long as the cephalis. The third large prismatic joint bears twelve parallel ribs, six new ribs being intercalated between the six former. Fourth joint short, cylindrical, without ribs, the wide open mouth not constricted, nearly as broad as the third joint, which is the broadest. Pores small, irregular, polygonal, or roundish.

Dimensions.—Length of the shell (with four joints) 0.2, breadth 0.12. Length of the single joints, a 0.03, b 0.05, c 0.08, d 0.04.

Habitat.—North Pacific, Station 244 (off Japan), depth 2900 fathoms.

3. Stichopilium bicorne, n. sp. (Pl. 77, fig. 9).

Shell conical, with three slight strictures. Length of the four joints = 4 : 14 : 5 : 3. Cephalis large, conical, with two stout pyramidal, divergent horns of twice the length. From its base (in the middle of the collar stricture) arise three internal, downwardly divergent ribs, which are prolonged on the outside of the upper half of the thorax into three stout, pyramidal, lateral spines (similar to the horns). The fourth joint, with wide open mouth, was the broadest, but not fully developed in the single specimen observed. Pores subregular, hexagonal, with thin bars.

Dimensions.—Length of the shell (with four joints) 0.02, breadth 0.09. Length of the single joints, a 0.02, b 0.07, c 0.025, d 0.015.

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

4. Stichopilium davisianum, Haeckel.

Pterocodon davisianus, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 298, Taf. ii. fig. 10.

Cycladophora davisiana, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 289, Taf. ii. fig. 11.

Eucyrtidium davisianum, Haeckel, 1862, Monogr. d. Radiol., p. 328.

Pterocanium davisianum, Haeckel, 1862, Monogr. d. Radiol., p. 332.

Shell campanulate, conical, with three slight strictures. Length of the four joints = 2 : 3 : 4 : 3. Cephalis hemispherical, with few small pores and a short conical horn. Thorax campanulate, with