Description:
<jats:p>The following parasites of the genera <i>Spirogyra</i> Link, <i>Mougeotia</i> Agardh and <i>Oedogonium</i> Link are desribed: <i>Myzocyutium irregulare, Woroninu glomerata, Harpochytrium tenuissimum, Woronina polycystis, Chytridium acuminatu, Myzocytium irregulare</i> and <i>Chytridumm acuminatum</i> are new to Poland. Also, the first information on <i>Woronina polycystis</i> as a parasite on algae is presented. The figure of cystosori in a cell of <i>Mougeotia mysorensis</i> is the first graphic documentation of this species.</jats:p>