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

A. Acanthometra (without complete lattice-shell).

B. Acanthophracta (with complete lattice-shell).

III. MONOPYLEA or NASSELLARIA.

Membrane of the central capsule simple, perforated by a porous-area, or by one single large opening, divided into numerous very fine pores. Fundamental form originally monaxon or egg-shaped. Skeleton siliceous. No phæodium in the extracapsular calymma. The Monopylea comprise two orders:—

A. Plectellaria (without complete lattice-shell).

B. Cyrtellaria (with complete lattice-shell).

IV. CANNOPYLEA or PHÆODARIA.

Membrane of the central capsule double, perforated by one simple main-opening, prolonged into a tubulus, and besides this commonly by one or two (rarely more) small accessory openings. Fundamental form originally monaxon or egg-shaped. Skeleton siliceous. Constantly a peculiar dark pigment-body or "phæodium" in the extracapsular calymma. The Cannopylea comprise two orders:—

A. Phæocystina (without lattice-shell).

B. Phæocoscina (with lattice-shell).