Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, First Part: Porulosa (Spumellaria and Acantharia) / Report on the Scientific Results of the Voyage of H.M.S. Challenger During the Years 1873-76, Vol. XVIII

by Ernst Haeckel

Dimensions.—Length of the disk (with three rings) 0.18, breadth 0.1; pores 0.001 to 0.006.

Habitat.—Western Tropical Pacific, Station 225, depth 4475 fathoms.

Subfamily 4. Stylodictyida, Haeckel, 1881, Prodromus, p. 459.

Definition.—Porodiscida with solid radial spines on the margin of the concentrically annulated disk, situated in the equatorial plane of the disk (without chambered arms and marginal oscula).

Genus 218. Xiphodictya,[^[257]] Haeckel, 1881, Prodromus, p. 460.

Definition.—Porodiscida with two opposite, solid, radial spines on the margin of the circular or elliptical disk.

The genus Xiphodictya opens the series of the Stylodictyida or of those Porodiscida in which the margin of the chambered disk is armed with solid radial spines, all situated in the equatorial plane of the disk. Xiphodictya exhibits the minimum number of spines, two being opposite on the poles of one equatorial axis of the disk. It repeats, therefore, in this family the same amphistylic formation as Sethostylus in the Phacodiscida and Stylocyclia in the Coccodiscida.

Subgenus 1. Xiphodictyon, Haeckel.

Definition.—All rings of the disk concentric, circular.

1. Xiphodictya amphibelonia, n. sp. (Pl. [42], fig. 10).