Page:Scientific results HMS Challenger vol 18 part 2.djvu/512

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Definition.—Shell flatly conical, often widely campanulate, or nearly discoidal. Cephalis commonly with two or more horns.

7. Clathrocyclas alcmenæ, n. sp. (Pl. 59, fig. 6).

Shell conical, with two indistinct strictures. Length of the three joints = 2 : 10 : 1, breadth = 2 : 12 : 14. Cephalis hemispherical, with two divergent, pyramidal horns; frontal horn as long as the cephalis, occipital horn of twice the length. Thorax conical, with large hexagonal meshes, increasing gradually in size towards the short abdomen, which is represented only by a single circular girdle of small, square, abdominal pores. Coronal of the peristome with twenty to thirty triangular, divergent, nearly horizontal feet, as long as the cephalis.

Dimensions.—Length of the three joints, a 0.02, b 0.1, c 0.01. breadth, a 0.02, b 0.12, c 0.14.

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

8. Clathrocyclas europæ, n. sp. (Pl. 59, figs. 11, 12).

Shell conical, almost of the same form as the preceding nearly allied species, differing from it in the concave (not straight) outline of the flatter conical thorax, in the more rounded form of its pores, and in the subspherical form of the cephalis, bearing only a single conical horn of the same length. Length of the three joints = 2 : 8 : 1, breadth = 2 : 12 : 14. In fig. 11 the cephalis is broken off, so that the four cortinar pores are visible (two smaller jugular and two larger cardinal pores, separated by two coracal beams).

Dimensions.—Length of the three joints, a 0.02, b 0.08, c 0.01. breadth, a 0.02, b 0.12, c 0.14.

Habitat.—Mediterranean, Corfu (Haeckel), surface.

9. Clathrocyclas semeles, n. sp. (Pl. 58, fig. 5).

Shell conical-campanulate, with two distinct strictures. Length of the three joints = 2 : 8 : 1, breadth = 2 : 8 : 10. Cephalis hemispherical, with three divergent, conical horns (the caudal horn, directed downwards, much longer than the occipital and frontal horns). Pores of the thorax large, roundish. Abdomen (as in the two preceding species) with only a single circle of forty to fifty small square pores. Coronal with about the same number of short, triangular, almost horizontally divergent feet.

Dimensions.—Length of the three joints, a 0.02, b 0.08, c 0.01. breadth, a 0.02, b 0.08, c 0.1.

Habitat.—Central Pacific, Station 271, surface.

10. Clathrocyclas danaës, n. sp. (Pl. 59, figs. 13, 14).

Shell flatly conical, with straight outline (as in Clathrocyclas alcmenæ, Pl. 59, fig. 6). Length of the three joints = 1 : 5 : 1, breadth = 2 : 8 : 1. Cephalis hemispherical, with a single, short, conical,