Page:Scientific results HMS Challenger vol 18 part 2.djvu/637

Rh 3. Cyrtocapsa inflata, n. sp.

Shell spiny, pear-shaped, with three deep strictures. The inflated third joint is twice as long as the second and fourth joints, and three times as long as the hemispherical cephalis, which bears a large conical horn of three times the length. Fourth joint flat, vaulted, inversely cap-shaped. The third joint is the broadest, being twice as broad as long. Pores regular, circular, double-contoured.

Dimensions.—Length of the shell 0.14, breadth 0.11. Length of the single joints, a 0.02, b 0.03, c 0.06, d 0.03.

Habitat.—North Pacific, Station 244, depth 2900 fathoms.

4. Cyrtocapsa pyrum, n. sp. (Pl. 78, fig. 8).

Shell thorny, pear-shaped, without external strictures, but with three internal annular septa. Length of the four joints = 2 : 5 : 6 : 7. The fourth joint is the broadest, being about twice as broad as long, and hemispherical. The small subspherical cephalis bears a stout conical horn of the same length. Pores large, regular, circular.

Dimensions.—Length of the shell (with four joints) 0.2, breadth 0.12. Length of the single joints, a 0.02, b 0.05, c 0.06, d 0.07.

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

5. Cyrtocapsa cornuta, n. sp. (Pl. 78, fig. 9).

Shell rough, very thick-walled, nearly pear-shaped, with three annular strictures; the second of which is very sharp, the first and third slight. Length of the four joints = 3 : 4 : 5 : 6. The third joint is the broadest, being about twice as broad as long; the fourth joint is hemispherical. Cephalis subspherical, with a large, conical, curved horn of twice the length. Pores regular, circular, hexagonally framed.

Dimensions.—Length of the shell (with four joints) 0.18, breadth 0.12. Length of the single joints, a 0.03, b 0.04, c 0.05, d 0.06.

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

6. Cyrtocapsa diploconus, n. sp. (Pl. 78, fig. 6).

Shell rough, doubly conical, with three annular septa. Length of the four joints = 3 : 4 : 4 : 8. The third joint is the broadest, two and a half times as broad as long; the fourth is inversely conical, acute. Cephalis hemispherical, with a pyramidal horn of the same length. Pores irregular, roundish.

Dimensions.—Length of the shell (with four joints) 0.19, breadth 0.1. Length of the single joints, a 0.03, b 0.04, c 0.04, d 0.08.

Habitat.—Tropical Atlantic, Station 347, depth 2250 fathoms.