Didymozoontidae, [73]

Digaster, [358], [359], [382] f.

Digenea (Digenetic Trematodes), [5], [52], [62], [73];

occurrence and habits, [62];

life-histories, [63] f., [71] f.

Digestive system, of Leptoplana, [11], [12];

of Polyclads, [24];

of Triclads, [37], [39];

of Rhabdocoelida, [42] f.;

of Temnocephala, [53], [54];