Order VI. CYRTELLARIA, Haeckel, 1881. - 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 - 6 - Ernst Haeckel

Suborder III. STEPHOIDEA, Haeckel.Suborder I. SPYROIDEA, Haeckel.

Order VI. CYRTELLARIA, Haeckel, 1881.

Definition.—Nassellaria with a complete lattice-shell enveloping the central capsule.