5. Lithocyclia heteropora, n. sp.
Phacoid shell two and a third times as broad as the medullary shell, surrounded by five to nine chambered rings, which are divided by piercing radial beams each into fifty to seventy chambers. Margin of the disk smooth. Pores very different in the inner and outer part of the surface; in the phacoid shell larger, regular, circular, eight on its radius, in the chambered periphery very small and irregular, somewhat spongy.
Dimensions.—Diameter of the disk (with nine rings) 0.2, of the phacoid shell 0.13, of the medullary shell 0.055.
Habitat.—Pacific, central area, Station 263, depth 2650 fathoms.
Genus 197. Coccodiscus,[[236]] Haeckel, 1862, Monogr. d. Radiol., p. 485.
Definition.—Coccodiscida with simple circular margin of the disk, without radial appendages. Medullary shell double.
The genus Coccodiscus has quite the same form and structure as the preceding Lithocyclia, and differs from it only in the double medullary shell, composed of two concentric latticed spheres; sometimes the inner medullary shell is spherical, the outer lenticular; the latter is connected with the lenticular phacoid shell (or cortical shell) by radial beams.
1. Coccodiscus lamarckii, n. sp. (Pl. [36], fig. 1).
Phacoid shell (or lenticular porous cortical shell) very thick walled (as thick as one ring), three times as broad as the outer and seven times as broad as the inner medullary shell, surrounded by two to three chambered rings of equal breadth, each of which is divided by piercing radial beams into thirty-six to forty square chambers. Margin of the disk circular, smooth. Pores regular, circular, of equal size; ten on the radius of the phacoid shell, two on the breadth of each chamber.
Dimensions.—Diameter of the disk (with two rings) 0.2, of the phacoid shell 0.14, outer medullary shell 0.05, inner 0.02.