Pandorina morum (ternary), [128], [129];

Eudorina, [129];

Peritrichaceae, [151], [157];

Vorticella, [157]

Syphilis in relation to Treponema pallidum, [121]

Syringolites, [344]

Syringopora, [283], [329], [343], [344]

Syzygy (= association) of Gregarines, [99];

in Crinoids, [582], [587]

Tabulae, [257], [345], [385], [387]