Physocypria kliei Schäfer, 1934, was found in water-bodies near Maarssen and Simonshaven (The Netherlands). It can be characterized as an oligohaline species occurring all the year round. The species is new to the Dutch fauna. It is concluded that Physocypria perlata Rome, 1943, is a junior synonym of P. kliei Schäfer, 1934. Potamocypris unicaudata Schäfer, was collected in a water-body near Rockanje (The Netherlands). Evidence is provided that Potamocypris vanoyei De Vos, 1946, is a junior synonym of P. unicaudata Schäfer, 1943.