Living material of Cosmocladium saxonicum De Bary was collected from 4 years old dug out moorland pools near Lochem (Province of Gelderland, the Netherlands) in August 2004. The find is the first record of this species in the Netherlands since the 1930s. The characteristic structure of the colony of Cosmocladium saxonicum appears not to stand any fixation with formalin. Within 24 h after fixation the connection strands between the cells become almost invisible, the cells being clumped together. Already a few days after fixation only scattered cells can be detected. These separate cells of Cosmocladium saxonicum may easily be confused with small-sized forms of Cosmarium contractum Kirchner. Consequently, in fixed material Cosmocladium saxonicum is likely to be overlooked.