EN
The data for Prismatolaimus dolichurus de Man, 1880, P. intermedium (Bütschli, 1873) and P. matoni Mulk et Coomans, 1979 are evaluated to state variability level, relationships between dimensions and ratios as well as similarity among studied populations. Relationship between coefficient of variability (CV) and the ratio of extreme values (Max:Min) is investigated. Guidelines for using the cluster analysis for comparison and differentiation of populations (species) are given.