Cyclostomata, [477], [479], [506], [517], [518], [525], [531];

occurrence, [478];

external characters, [480];

ovicells, [507];

reproduction, [507], [511];

larva, [511]; fossil, [520], [521]

Cydippe, as host, [298]

Cylindroecium, [533]

Cylindrostoma, [46];

British species, [50]