New species of water striders (Hemiptera: Heteroptera: Gerro- morpha: Hydrometridae, Gerridae) from Eocene Baltic amber

New species of two hitherto monotypic genera of water striders are described from Baltic amber inclusions: Metrocephala schaeferi nov. spec. is compared with Metrocephala anderseni PoPov, 1996 (Hydrometridae), and Succineogerris nilsi nov. spec. with Succineogerris larssoni Andersen, 2000 (Gerridae). Additional descriptive notes and illustrations are presented for the type material of S. larssoni.