Cymbella has undergone a number of revisions in recent years, with the ‘broad’ concept, as used by Hustedt (1927-66, 1930) and Krammer and Lange-Bertalot (1986) gradually being replaced by a number of more circumscribed genera. Some of these are resurrections of old genera (e.g. Kützing’s Encyonema) whilst others are new