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

Order V. PLECTELLARIA, Haeckel, 1883.

Definition.—Nassellaria without complete lattice-shell, usually with an incomplete skeleton, formed of a ring, a tripod, or an irregular framework.