Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, Second Part: Subclass Osculosa; Index / 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 apical spine 0.26, of the three basal spines 0.17.

Habitat.—Central Pacific, Station 274, surface.

3. Periplecta monocyrtis, n. sp.

Spines of nearly equal size and shape, cylindrical, irregularly branched. The apical spine is straight, more branched and nearly twice as long as the three basal spines. All four spines in the basal third connected by a loose spongy framework, approaching the form of some Monocyrtida.

Dimensions.—Length of the apical spine 0.24, of the basal spines 0.13.

Habitat.—Central Pacific, Station 274, surface.

Subfamily 3. Hexaplectica, Haeckel.

Definition.—Plectanida with six radial spines.

Genus 398. Hexaplecta,[^[17]] Haeckel, 1881, Prodromus, p. 425.

Definition.—Plectanida with six radial spines, arising from one common central point.