Abstract
During recent investigations on Endamoeba blattae (Bütschli) Leidy of the common cockroach, Blatta orientalis, there were observed in the hindgut of the host, two other distinct amoebic species. Both appear to be truly entozoic, but contrast strikingly with E. blattae both in morphological features and life cycle. They are interesting not only in being among the comparatively few species yet reported from insects, but also in their relationships to certain of the amoebae of vertebrates.