Abstract
The valve morphology and ultrastructure of the the so-called “stelligeroid” taxa of the genus Cyclotella (Kützing) Brébisson (Bacillariophyceae) are discussed. These taxa have marginal mltoportulae and the rimoportula(e) positioned between costae. As this and other discussed characters do not fit the current description of the genus Cyclotella (Kützing) Brébisson nom. cons., the formal transfer of these taxa into a new genus, Discostella gen. nov., is proposed.