Page:Scientific results HMS Challenger vol 18 part 2.djvu/624

1500 1. Siphocampe tubulosa, n. sp. (Pl. 79, fig. 13).

Shell slender nearly spindle-shaped, with eight deep transverse strictures, and elegant longitudinal ribs. Nine joints slightly different in length and shape. Cephalis flat, cap-shaped, with three or four transverse rows of small pores, and a cylindrical, oblique tubule of twice the length. Each successive joint with a single transverse row of regular, circular pores at its lower edge, separated by divergent, longitudinal ribs. Last joint shorter, with a hyaline annular peristome of the same length. Mouth half as broad as the middle part of the shell.

Dimensions.—Length of the shell (with nine joints) 0.24; length of each joint (on an average) 0.02 to 0.03; breadth 0.08.

Habitat.—Western Tropical Pacific, Station 225, depth 4475 fathoms.

2. Siphocampe annulosa, n. sp. (Pl. 79, fig. 10).

Shell slender, subcylindrical, with nine slight transverse strictures, and interrupted longitudinal ribs. Ten joints nearly equal in length and shape, excepting the two first, which together form a hemispherical cephalothorax, with six to eight transverse rows of pores. Tubule of the cephalis short and wide, truncate, conical. Each of the eight abdominal joints with a single transverse row of small pores. Mouth constricted, without tubulose peristome, half as broad as the shell.

Dimensions.—Length of the shell (with ten joints) 0.18; length of each joint (on an average) 0.02, breadth 0.07.

Habitat.—Central Pacific, Station 274, depth 2750 fathoms.

3. Siphocampe caminosa, n. sp. (Pl. 79, fig. 12).

Shell slender, subcylindrical, with six deep transverse strictures. Seven joints nearly equal in length and breadth. Cephalis hemispherical, with an oblique, cylindrical tubule of twice the length (in the figure the greater part is broken away). Small circular pores in transverse rows and in variable number; usually three rows in the first and the last joint, five rows in the fourth joint, four rows in each of the other joints. Mouth constricted, with a short tubulose peristome, only one-third as broad as the shell.

Dimensions.—Length of the shell (with seven joints) 0.18; length of each joint (on an average) 0.025, breadth 0.055.

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

4. Siphocampe erucosa, n. sp. (Pl. 79, fig. 11).

Shell slender, nearly spindle-shaped, with five slight transverse strictures. Six joints nearly equal in length. The two first joints are united, and form together a hemispherical cephalothorax, with a short, oblique, cylindrical tubule. Pores regular, circular, double-contoured, in regular, transverse rows; two rows in the first and the last joints, four rows in each of the four middle joints. Mouth constricted, without peristome, only one-third as broad as the shell.