Beschreibung:
<jats:p><jats:bold>SYNOPSIS. </jats:bold> Three acidophilous volvocine flagellates from peat water in Czechoslovakia were obtained in pure culture by the washing technique. Two of these, <jats:italic>Carteria acidicola</jats:italic> and <jats:italic>Chlamydomonas acidophila</jats:italic>, grew so densely in low‐pH <jats:italic>Euglena gracilis</jats:italic> media containing glutamic acid as to suggest they possess a vigorous heterotrophy. The other, <jats:italic>Carteria turjosa</jats:italic>, grew less well and required vitamin B<jats:sub>12</jats:sub>. In peat‐water media the upper limit of growth was 5.5. The lowest pH tested, 2.5, permitted growth of <jats:italic>Carteria acidicola</jats:italic> and <jats:italic>Chlamydomonas acidophila.</jats:italic> Some peptone media permitted growth at pH 6.0. The morphology of these flagellates is described.</jats:p>