Small green algae traditionally referred to Epicladia flustrae and found associated with bryozoans and hydroids were compared by studying material from nature and plants isolated into unialgal culture. No true parenchyma or hairs were observed in any of these algae. The new species Epicladia phillipsii and Pseudendoclonium dynamenae are established. The species are associated with different host animals with some host specificity; thus E. flustrae has been noted only in the bryozoans Flustra foliacea and Securiflustra securifrons, E. phillipsii only in Alcyonidium hirsutum, and P. dynamenae only in the hydroid Dynamena pumila.