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.—Radius of the anterior arms 0.6, of the posterior 0.5; longitudinal constriction 0.4, transverse 0.35.

Habitat.—South Pacific, Station 288, surface.

10. Myelastrum lobatum, n. sp.

Anterior arms somewhat broader but shorter than the posterior arms. Each arm four-lobed, with three terminal shallow incisions of nearly equal size. Sagittal constriction smaller than the transverse. Surface of the disk bristly.

Dimensions.—Radius of the anterior arms 0.4, of the posterior 0.5; longitudinal constriction 0.3, transverse 0.35.

Habitat.—North Pacific, Station 253, surface.

11. Myelastrum rotula, n. sp.

Anterior arms little broader than the posterior, but of the same length. Each arm four-lobed, with three terminal deep incisions of equal size. Sagittal and transverse constrictions equal. The whole disk nearly circular, resembles a wheel with sixteen spokes. Surface smooth.

Dimensions.—Radius of all four arms 0.5; longitudinal and transverse constrictions 0.3.

Habitat.—Pacific, central area, Station 274, surface.