of Dinophilus, [243];

of Chaetopterus, [324];

of Myzostoma, [342];

of larva of Polyzoa, [509], [511]

Summer-eggs, of Mesostoma, [48];

of Rotifera, [216]

Sutroa, [376], [380]

Swim-bladder, of Syllidae, [272]

Swimming, of Leptoplana, [9], [10];

of Polyclads, [23];