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

C. The Discoidal, Spheroidal, or Lenticular Central Capsule, with one axis shorter than the others, which becomes the vertical main axis.

a. Among the Spumellaria, Actidiscus (p. [15]), Collodiscus (p. [27]), and the large group Discoidea (p. [408]).

b. Among the Acantharia, many Quadrilonchida (p. [768], Pl. [131]), and most Hexalaspida (p. [874]).

c. Among the Nassellaria, certain Stephoidea and Cyrtoidea.

d. Among the great legion Phæodaria the spheroidal central capsule is almost always more or less flattened in the direction of the main axis (p. [1525], Pls. [101]-[128]).

D. The Lentelliptical Central Capsule (or triaxial ellipsoid), with three unequal but isopolar axes at right angles to each other, the sections in all three dimensions of space being ellipses.

a. Among the Spumellaria, Actilarcus and the large group Larcoidea (p. [604]).

b. Among the Acantharia, certain Amphilonchida and Belonaspida.

E. The Polymorphic, Amœboid or Irregular Central Capsule.

a. Among the Spumellaria, Collodastrum (p. [28], Pl. [3], figs. 4, 5), and some Larcoidea.