Stylocyclia amphistyla, Haeckel, 1879, MS. et Atlas (pl. xxxvii. fig. 7).
Phacoid shell thin walled, two and a half times as broad as the outer and seven times as broad as the inner medullary shell, divided by eighty to ninety radial beams into irregular chambers, which are stratified in four to five floors. Pores regular, circular; eight to nine on the radius of the phacoid shell, two on the breadth of each chamber. Both marginal spines cylindrical.
Dimensions.—Diameter of the disk (with seven rings) 0.27, of the phacoid shell 0.1, outer medullary shell 0.04, inner 0.014.
Habitat.—North Atlantic, Canary Islands, Station 354, surface.
3. Amphicyclia pachydiscus, n. sp. (Pl. [38], fig. 2).
Phacoid shell very thick, spongy, twice as broad as the outer and five times as broad as the inner medullary shell, divided by fifty to seventy radial beams into subregular chambers, which are stratified in five to six floors. Pores irregular, roundish; ten to twelve on the radius of the phacoid shell, two to three on the breadth of each chamber. The two opposite marginal spines quadrangular prismatic, very long, as broad as the radius of the inner medullary shell. Fig. 2 exhibits a vertical section (slide) through the centre.
Dimensions.—Diameter of the disk (with five rings) 0.22, of the phacoid shell 0.1, outer medullary shell 0.05, inner 0.02.
Habitat.—South Atlantic, Station 332, depth 2200 fathoms; fossil in Barbados.
Genus 200. Trigonocyclia,[[239]] Haeckel, 1881, Prodromus, p. 458.
Definition.—Coccodiscida with three solid radial spines on the margin of the circular disk. Medullary shell simple.