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

7. Myelastrum decaceros, n. sp. (Pl. [47], fig. 7).

Anterior arms bifid, with one shallow incision at their distal end. Posterior arms of the same length, but much broader, trifid, with two incisions (one larger and one smaller). Sagittal and transverse constrictions of the same length. Surface spiny.

Dimensions.—Radius of all four arms 0.4; longitudinal and transverse constrictions 0.35.

Habitat.—Pacific, central area, Station 272, surface.

8. Myelastrum dodecaceros, n. sp. (Pl. [47], figs. 11, 11a).

Anterior arms trifid, with two shallow incisions at their distal end. Posterior arms about one-third larger, also trifid, with one deeper anterior and one shallower posterior incision. Sagittal constriction much longer than the transverse. Surface ciliated, covered with numerous thin and long radial bristles (fig. 11a).

Dimensions.—Radius of the anterior arms 0.5, of the posterior 0.7; longitudinal constriction 0.5, transverse 0.35.

Habitat.—Pacific, central area, Station 270, surface.

9. Myelastrum ciliatum, n. sp.

Anterior arms trifid, with two shallow incisions. Posterior arms somewhat smaller, also trifid, with two deeper incisions. Sagittal constriction a little larger than the transverse. Margin of the disk ciliated, with radial bristle-shaped spines, as prolongations of the inner radial beams, arising from the central disk.