Lectotypes are designated for Cordylura dentimana Zetterstedt, 1838, Cordylura fulvipes Zetterstedt, 1838, Cosmetopus bergrothi Becker, 1900, and Cosmetopus simplicipes Becker, 1900. C. fulvipes Zett. is found to be a synonym of C. dentimana Zett. (n. syn.). The opinion that C. bergrothi is a synonym of Cosmetopus longus (Walker, 1849) and that C. simplicipes Beck. should be treated in a separate genus, Pleurochaetella Vockeroth, is confirmed. Cosmetopus ringdahli n. sp. is described and figured on material from Sweden and Finland. Distinctive characters of the other species are discussed and partly figured.