Enneophthalmus Billberg [G. J.] 1833:50 Masc. Based on Enneophthalmus of Willughby 1686:107, Pl. G3, fig. 1 [ref. 30164], which is based on a drawing by L. Baldner. Genus indistinguishable within Petromyzontidae, therefore nomen nudum; see Kullander 2016:106 [ref. 34147]. Nomen Nudum. Petromyzontidae.