Mecynocera clausi I.C. Thompson, 1888 is the type genus and species of the monotypic family Mecynoceridae Andronov, 1973. Based on the first description of male mouthparts of Mecynocera clausi Thompson, 1888 (Copepoda: Calanoida), evidence is presented for the transfer of this genus and species to the Paracalanidae Giesbrecht, 1893. Thus, Mecynoceridae Andronov, 1973 becomes a junior synonym of...