Microporella, [516], [518], [519], [529];

avicularia, [484], [485];

median pore, [501]

Microscolex, [372], [382], [383], [384]

Microstoma, [44];

asexual reproduction, [44];

sexual organs, [47];

British species, [49]

Microstomatidae, [49]

Micrura, [101], [114];