Page:Scientific results HMS Challenger vol 18 part 2.djvu/730

1606 1. Sagena ternaria, n. sp. (Pl. 108, fig. 8).

Network subregular, with equilateral triangular meshes, intermingled with single irregular meshes (fig. 8). Bars of the network smooth, its nodal points solid, not pierced.

Dimensions.—Diameter of the spherical shell 1.5 to 2.5, length of the bars 0.1 to 0.2, breadth 0.002 to 0.005.

Habitat.—Cosmopolitan; Mediterranean, Atlantic, Indian, Pacific, surface.

2. Sagena pertusa, n. sp.

Network subregular, with nearly equal triangular meshes. Bars of the network smooth, its nodal points pierced by a circular hole.

Dimensions.—Diameter of the shell 1.2 to 1.8, length of the bars 0.2 to 0.25, breadth 0.003.

Habitat.—Central Pacific, Stations 270 to 274, surface.

3. Sagena triangula, n. sp.

Network very regular, with equilateral triangular meshes. Bars of the network spinulate, like those of Sagoplegma spinulosa. (Pl. 108, fig. 14), its nodal points solid, not pierced.

Dimensions.—Diameter of the shell 2.2, length of the bars 0.25, breadth 0.004.

Habitat.—South Atlantic, Station 325, surface.

4. Sagena crucifera, n. sp.

Network more or less irregular, with unequal triangular meshes. Bars of the network studded with scattered, rectangular, minute crosses, arising perpendicularly, each cross composed of four small equal bars. Nodal points partly solid, partly pierced by a hole. Network very similar to that of Dictyosoma trigonizon, figured in my Monograph, Taf. xxvi. figs. 4, 5.

Dimensions.—Diameter of the shell 1.5, length of the bars 0.1 to 0.2, breadth 0.003.

Habitat.—Mediterranean, Atlantic, Canary Islands, Station 353, surface.

Definition.— with a delicate spherical shell, the thin wall of which is composed of a simple lattice-plate, and bears on its nodal points radial spines.

The genus Sagosphæra differs from the preceding Sagena, its ancestral form, in the development of radial spines on the nodal points of the simple delicate lattice-sphere. It exhibits therefore the same relation to the latter as Aulosphæra bears to Aularia.