vibracula, [487]

Selenka, on Sipunculids, [424] n., [447]

Self-fertilisation, in certain Mesostoma, [48];

in Trematodes, [52], [58];

in Cestodes, [86]

Semper, on excretory system of Nemertinea, [108];

on Geonemertes palaensis, [101] n., [117];

on mimicry in Polychaeta, [294]

Sense-organs, of Leptoplana, [13];

of Polyclads, [26];