Diagnostic features of Rotifera: Monogononta are summarized, and a dichotomous key to the ploimate rotifers is followed by detailed diagnostic keys to the planktonic and facultatively planktonic representatives of the Epiphanidae (Proalides, Epiphanes, Cyrtonia, Rhinoglena and Microcodides) and Brachionidae (Platyias, Brachionus, Keratella, Kellicottia, Notholca and Anuraeopsis). All species known from Australian inland waters are described and figured, as are some widely distributed taxa not yet recorded from the continent. Distribution data and ecological information are also given.