The types of Confluaria capillaris (Rudolphi, 1810) from Podiceps auritus in (?) Germany and the types of C. capillaroides (Fuhrmann, 1906) from Podiceps dominicus in Brazil are redescribed. C. capillaroides is recognised as a junior synonym of C. capillaris (new synonymy). Data on specimens of the same species from P. cristatus and P. grisegena in Bulgaria are also presented. The previous records of the two nominal species are critically analysed in view of the present redescriptions. The host range of C. capillaris includes only grebes of the genus Podiceps, i.e. P. auritus, P. cristatus, P. grisegena, P. dominicus and P. nigricollis; the records in other hosts (Gaviiformes, Charadriiformes and Passeriformes) are considered erroneous or doubtful. The geographical range includes Europe, Central Asia and northern South America.