on Salinella, [96]

Fresh-water, Turbellaria, compared with marine, [46];

Nemertinea, [101], [118];

Polychaeta, [284];

Polyzoa, [492]

Friend, on Oligochaeta, [388] n.

Frogs, Trematodes of, [55], [58], [62], [71] f.;

Nematodes of, [140], [142], [160], [173]

Frontal organ, of Nemertinea, [107]

Frontal palps, of Eunicidae, [318] f.