Funiculina, [359], [362];

F. quadrangularis, [362]

Funiculinidae, [362]

Funnel, of Craspedomonadidae or Choanoflagellates, [111], [121], [122], [182];

of Phalausteridae, [111];

of choanocytes of Sponges, [171]

Fusion of larval Sponges, [174]

Fusion-nucleus of Ciliata, [150]

—see also Reproduction, Syngamy, Zygotonucleus

Fusulina, [59]