Peristalsis of intestine of Holothuria nigra, [563]
Peristome, of Ciliata, [137] f.;
in fission, [147];
of Peritrichaceae, [155] f.;
of Vorticellidae, [155] f., [157];
of Asterias rubens, [434];
of Echinus esculentus, [505], [513], [514];
of Asteroidea, [514];