Page:Scientific results HMS Challenger vol 18 part 1.djvu/570

362 Dimensions.—Main axis of the cortical shell 0.11, equatorial axis 0.06; meshes 0.01 to 0.02, bars 0.002; diameter of the medullary shell 0.02.

Habitat.—Atlantic, Canary Islands (Lanzerote), surface.

Definition.—Surface of the cortical shell spiny, everywhere scattered with numerous thorns or spines.

5. Cyphanta hispida, n. sp.

Cortical shell thick walled, with spiny surface; pores regular, circular, with hexagonal frame, twice as broad as the bars; twelve to fourteen on the half meridian, eight to ten on the half equator. From the corners of the hexagonal frames (between every three pores) arise short, straight, conical radial spines, somewhat longer than the breadth of the pores. Medullary shell subspherical, its diameter about one-third of the equatorial axis of the cortical shell. (The appearance of the cortical shell is the same as that of the middle part of Peripanartus amphiconus, Pl. 40, fig. 5.)

Dimensions.—Main axis of the cortical shell 0.12, equatorial axis 0.07; meshes 0.01, bars 0.005; length of the spines 0.012; diameter of the medullary shell 0.02.

Habitat.—Pacific, central area, Station 274, depth 2750 fathoms.

6. Cyphanta hystrix, n. sp.

Cortical shell thin walled, with thorny surface; pores irregular, roundish, of very unequal size, twice to six times as broad as the bars; twelve to eighteen on the half meridian, eight to thirteen on the half equator. Between the pores irregularly scattered, bristle-like, thin spines about the same size, partly straight, partly oblique, rising from the surface. Medullary shell lenticular, compressed, its equatorial axis one and a half times the length of the main axis, and about half that of the cortical shell.

Dimensions.—Main axis of the cortical shell 0.15, equatorial axis 0.09; meshes 0.004 to 0.02, bars 0.003 to 0.006; length of the spines 0.02; diameter of the medullary shell 0.04.

Habitat.—South Atlantic, Station 318, surface.

Definition.— with simple cortical shell and double medullary shell, without polar spines or tubes.

The genus Cyphonium contains a number of very common species, among which are the earliest known forms of this family, partly described by Ehrenberg as Ommatospyris