Zonarial Radiolaria, [75]

Zoochlorella, [111];

a Chlamydomonad, [126];

symbiotic, in Heliozoa, [73];

in Paramecium bursaria, [153];

in Stentor polymorphus, [154];

in Ophrydium, [158];

in Ephydatia, [175];

in Hydra viridis (= chlorophyll corpuscles), [256]

Zooids of Volvox globator, [127]