of contractile vacuole, [14];
of Ciliata, [143];
of Trachelius ovum, [153];
of embryonic cavity of Suctoria, not seen in Choanophrya, [161] n.;
of Sponges, [186], [187], [188], [189], [198]
Pore-canal, of Asterias rubens, [441];
of Ophiothrix fragilis, [486], [487];
of Echinus esculentus, [517];
of Echinocardium cordatum, [552];
of a larval Holothuroid, [564];