Aanvulling van de lijst van Nederlandse erwtenmossels met drie ‘nieuwe’ soorten (Bivalvia: Sphaeriidae)

The checklist of pea clam species (‘Pisidiums’) prevailing in the Netherlands has usually been considered to contain 14 species. Recently, however, Euglesa casertana forma plicata was identified as the species Euglesa compressa. This paper argues that two more ‘formas’ of E. casertana i.e., ponderosa and globularis, as well as forma crassa of Euglesa nitida, should be accepted as valid species. Consequently, the Dutch checklist of pea clams should also include Euglesa compressa, E. crassa, E. globularis and E. ponderosa, which raises the number of species on that list to 18.