Some obeservations of pseudo girdle bands in Closterium regulare. Closterium regulare is seen by Ruzicka (1977) as a Closterium with a girdle (“Gürtelband”), based on Krieger (1937) and West & West (1904). Coesel (1983) already came to the conclusion that this species most likely has no girdle band, but may have a pseudo girdle band. In 2007, however, Coesel & Meesters (2007) concluded that Closterium regulare has no girdle band at all. However, some observations in Zwanenwater (Callantsoog, The Netherlands) indicate that Closterium regulare exceptionally has pseudo-girdles, especially visible in empty cells.