Page:Scientific results HMS Challenger vol 18 part 2.djvu/642

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1518
THE VOYAGE OF THE H.M.S. CHALLENGER.

11. Stichocapsa radicula, Haeckel.

Lithocampe radicula, Ehrenberg, 1838 (partim); Mikrogeol., 1854, Taf. xxii. fig. 23b.?

Shell smooth, spindle-shaped, decreasing from the broader middle towards the two rounded poles, with four or five slight strictures. All five or six joints nearly equal in length, the middle (third and fourth) are the broadest. Pores subregular, circular. (To this species those forms of Lithocampe radicula, Ehrenberg, must be referred, in which the basal opening is perfectly closed by lattice-work. The other forms in which the basal mouth remains open, and which are connected with the former by transitional forms, constitute the true type of the genus Lithocampe (page 1503).

Dimensions.—Length of the shell (with six joints) 0.12 to 0.15, breadth 0.06 to 0.07.

Habitat.—Fossil in Barbados.


12. Stichocapsa subligata, Haeckel.

Lithocampe subligata, Stöhr, 1880, Palæontogr., vol. xxvi. p. 102, Taf. iv. fig. 1.

Shell rough, subcylindrical, irregular, with seven slight strictures. All eight joints of slightly different lengths, the third joint is the broadest; the seventh joint is much broader than the sixth and the eighth joints. The latter is inversely hemispherical. Cephalis very small, spherical. Pores regular, circular, very small and numerous.

Dimensions.—Length of the shell (with eight joints) 0.24; length of the single joints (on an average) 0.025 to 0.035, breadth 0.08.

Habitat.—Fossil in Tertiary rocks of Sicily (Grotte).


13. Stichocapsa paniscus, n. sp. (Pl. 76, fig. 4).

Shell smooth, cylindrical, with a blunt, conical cephalis, and a hemispherical last joint, without external strictures, but with seven or eight internal septa. Eight or nine joints nearly equal in length, the second and the last somewhat longer. Pores circular, of unequal sizes.

Dimensions.—Length of the shell (with seven joints) 0.16; length of each joint (on an average) 0.02 to 0.03, breadth 0.07.

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


14. Stichocapsa cylindrica, n. sp.

Shell rough, cylindrical, four times as long as broad, with hemispherical cephalis and last joint, without external stricture, but with ten or eleven internal septa. All eleven or twelve joints are nearly equal in length, and are three times as broad as long. Only the flat cephalis is shorter, and the vaulted last joint longer than each of the nine or ten other joints. Pores regular, circular.

Dimensions.—Length of the shell (with twelve joints) 0.24; length of each joint (on an average) 0.02, breadth 0.06.

Habitat.—Tropical Atlantic, Station 338, depth 1990 fathoms.