Page:Scientific results HMS Challenger vol 18 part 1.djvu/1022

814 sutural meshes. Radial spines in the outer half fusiform, somewhat longer than the inner cylindrical half.

Dimensions.—Diameter of the shell 0.08 to 0.09, of the parmal meshes 0.1 to 0.2, of the sutural meshes 0.004 to 0.01.

Habitat.—Central Pacific, Station 271, surface.

2. Dorataspis macracantha, n. sp.

Shell with fifty-two sutures and fifty-two sutural meshes; with four hexagonal and sixteen pentagonal plates. Both aspinal meshes of each plate circular, small, twice as broad as the small sutural meshes. Radial spines quadrangular, prismatic, their outer half twice to three times as long as the inner half.

Dimensions.—Diameter of the shell 0.12, of the parmal pores 0.008, of the sutural meshes 0.004.

Habitat.—South Pacific, Station 288, surface.

3. Dorataspis macropora, n. sp.

Shell with fifty-two sutures and one hundred to one hundred and fifty sutural meshes, with four hexagonal and sixteen pentagonal plates. Both aspinal meshes nearly circular, very large, five to ten times as broad as the small circular sutural meshes; the number of the latter is in this species multiplied, in each suture being two to three (commonly three) small pores. Radial spines in the outer half leaf-shaped, compressed, nearly lanceolate, longer than in the inner cylindrical half.

Dimensions.—Diameter of the shell 0.16, of the parmal pores 0.03 to 0.04, of the sutural pores 0.004 to 0.006.

Habitat.—Indian Ocean (Madagascar), Rabbe, surface.

Definition.—Shell with fifty-four sutures; four polar plates on each pole of the main axis different in pairs; two major hexagonal meeting in a polar suture (the "hydrotomical suture"); two minor pentagonal, not meeting together (separated by that hydrotomical suture). Spherical shell therefore composed of eight hexagonal plates (four equatorial and four polar) and by twelve pentagonal plates (eight tropical and four polar plates).

4. Dorataspis loricata, Haeckel.

Dorataspis loricata, Haeckel, 1862, Monogr. d. Radiol., p. 415, Taf. xxi. figs. 3-6.

Shell with fifty-four sutures and fifty-four sutural meshes, with eight hexagonal and twelve pentagonal plates. Both aspinal meshes of each plate kidney-shaped or roundish, nearly of the