Page:Scientific results HMS Challenger vol 18 part 1.djvu/321

Rh different numbers of the tubuli:—Disolenia with two tubes, Trisolenia with three tubes, Tetrasolenia with four tubes, Pentasolenia with five tubes, Polysolenia with six or more tubes. All these five genera are without value, as those different numbers of tubes occur frequently intermingled in the individual cells of one and the same colony, wherever the form and structure of the tubes is inherited with sufficient constancy to determine the species.

Definition.—Tubuli of the shell cylindrical or nearly cylindrical, the outer and inner apertures nearly of the same size.

1. Solenosphæra variabilis, Haeckel.

Tetrasolenia quadrata, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, Taf. x. fig. 20.

Shell quite irregular roundish or polyhedral, with roundish pores of different size. Ten to fifteen pores in the half meridian of the shell, two to three times as broad as the bars. Porous tubuli of the shell in variable number (in one and the same colony), three to nine, mostly four to six; cylindrical or subcylindrical or somewhat conical, two to three times as broad as long, not longer than the half radius of the shell. Inner aperture of the tubuli commonly as broad as the half radius of the shell (or somewhat smaller), about as large as the truncated outer aperture. This species is closely related to Collosphæra polyedra (p. 97), and may be derived from it by a short tube-like prolongation of the larger apertures.

Dimensions.—Diameter of the shell 0.1 to 0.16, of the pores 0.005 to 0.015; length of the tubules 0.02 to 0.03, breadth of them 0.04 to 0.06.

Habitat.—Central area of the Tropical Pacific, Stations 270, 271, 272, depths 2425 to 2925 fathoms.

2. Solenosphæra pandora, n. sp. (Pl. 7, figs. 10, 11).

Shell irregular roundish or subglobular, with roundish pores of different sizes, mostly somewhat broader than the bars. About twelve to sixteen pores on the half meridian of the shell. Porous tubuli of the shell of variable number (in one and the same colony), one to six, mostly three to four; cylindrical or nearly cylindrical, somewhat longer than broad, not longer than the radius of the shell. Inner aperture of the tubuli commonly as broad as the half radius of the shell, and a little smaller than the truncated outer aperture.

Dimensions.—Diameter of the shell 0.07 to 0.1, of the pores 0.003 to 0.006; length of the tubuli 0.03 to 0.05, breadth of them 0.02 to 0.03.

Habitat.—Central area of the Tropical Pacific, Stations 266 to 274, depths 2350 to 2925 fathoms.