Page:Scientific results HMS Challenger vol 18 part 2.djvu/635

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Definition.— (vel Stichocyrtida eradiata aperta) with spirally arranged constrictions on the shell. Cephalis without horn.

The genus Spirocampe has the same peculiar spiral structure of the shell as the preceding Spirocyrtis, and differs from it only in the absence of a cephalic horn. It exhibits, therefore, the same relation to the latter as the similar Lithocampe bears to Eucyrtidium.

1. Spirocampe callispira, n. sp. (Pl. 76, fig. 11).

Shell ovate, smooth, with six joints, connected in the form of a complete winding staircase. All the windings are nearly at equal distances; each bears one row of large roundish pores, enclosed by two rows of smaller pores. Cephalis hemispherical, of about the same breadth as the constricted, short tubular mouth.

Dimensions.—Length of the shell (with six joints) 0.15, breadth 0.09; mouth 0.03 diameter.

Habitat.—Central Pacific, Station 270, depth 2925 fathoms.

2. Spirocampe allospira, n. sp. (Pl. 76, fig. 12).

Shell subcylindrical, or nearly spindle-shaped, smooth, very thick-walled, with eight joints alternately longer and shorter, and connected in the form of an irregular spiral. The distance between the windings is very variable. Pores small, regular, circular. Cephalis hemispherical, of about the same size as the short tubular mouth.

Dimensions.—Length of the shell (with eight joints) 0.2, breadth 0.08; mouth 0.03 diameter.

Habitat.—Central Pacific, Station 273, depth 2350 fathoms.

3. Spirocampe polyspira, n. sp.

Shell cylindrical, rough, with twelve joints nearly equal in length, connected in the form of a regular, complete spiral. All windings are at the same distance. Pores regular, circular, three rows on each turning. Cephalis flat, cap-shaped, half as broad as the slightly constricted, not tubular mouth.

Dimensions.—Length of the shell (with twelve joints) 0.24, breadth 0.07; mouth 0.05 diameter.

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

Definition.— with the terminal mouth of the shell fenestrated (vel Stichocyrtida eradiata clausa).