The samples of the genus Calypogeia in the dutch institutional herbaria and private collections, those of C. arguta excluded, have been re-identified, according to the revision of the Swiss Calypogeias by Bischler (1957); distribution maps are given for all the taxa. More exact circumscriptions are given of several differentiating characters which were already established by previous authors. In C. fissa and C. sphagnicola the areolation of the leaves appeared to be a new differentiating character: in C. fissa the cells in the middle of the leaf show a great variation in length, whereas in C. sphagnicola the cell size is uniform. These differences are shown in histograms. C. muelleriana appeared to be restricted to the diluvial parts of the country, whereas C. fissa is common on both alluvium and diluvium; c. neesiana, C. sphagnicola and C. trichomanis are very rare, so that no clear geographical distribution can be given.