The article presents a proposal to preserve the name Cylindrotheca against Ceratoneis. According to the author, all records of Ceratoneis refer to the freshwater Hannaea arcus including its allies. There are no records that refer to marine diatoms of the family Bacillariaceae which includes the type Cylindrotheca and Nitzschia. Cylindrotheca is a model organism used for the study of diatom physiology and biochemistry.