Page:Scientific results HMS Challenger vol 18 part 1.djvu/1062

854

Definition.—Outer shell composed of twenty united plates, the sutures of their meeting condyles being grown together.

8. Phractopelta aspidomma, n. sp.

Outer shell composed of twenty united plates, the meeting condyles of which are grown together. On the base of each radial spine (where its outer free part arises from the surface of the outer shell), two large elliptical aspinal pores, two to four times as large as the other roundish pores. Radial spines compressed, sword-shaped, about as long as the radius of the shell.

Dimensions.—Diameter of the outer shell 0.1, of the inner 0.05.

Habitat.—Equatorial Atlantic, Station 347, surface.

9. Phractopelta haliomma, n. sp.

Outer shell composed of twenty united plates, the meeting condyles of which are grown together. On the base of each radial spine two large kidney-shaped aspinal pores, little larger than the other irregular pores. Radial spines compressed, linear, two-edged, much longer than the diameter of the shell.

Dimensions.—Diameter of the outer shell 0.09, of the inner 0.03.

Habitat.—South Pacific, Station 295, surface.

10. Phractopelta tessaromma, Haeckel.

Outer shell composed of twenty united plates, the meeting condyles of which are grown together. On the base of each radial spine four crossed egg-shaped aspinal pores, two opposite of which are much larger than the two others. Sutural pores irregular. Radial spines cylindrical or little compressed, thin, longer than the diameter of the shell.

Dimensions.—Diameter of the outer shell 0.1, of the inner 0.04.

Habitat.—Central Pacific, Station 266, surface.

11. Phractopelta hystrix, Haeckel.

Haliomma hystrix, J. Müller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 37, Taf. v. figs. 1, 2.

Aspidomma hystrix, Haeckel, 1862, Monogr. d. Radiol., p. 424.

Outer shell composed of twenty united plates, the meeting condyles of which are grown together. On the base of each radial spine four crossed circular aspinal spines of equal size. Sutural pores roundish, of about the same size. Radial spines conical, about as long as the radius of the shell.

Dimensions.—Diameter of the outer shell 0.07, of the inner 0.024.

Habitat.—Mediterranean (Nice), J. Müller, surface.