Fishes Class Myxini (Jaekel, 1911) see Subclass Myxinoidea Order Myxiniformes - hagfishes Family Myxinidae Rafinesque, 1815 - hagfishes Subfamily Eptatretinae Genus Heptatremus Swainson, 1839, nom. null. see Genus Heptatrema Duméril, 1832, nom. van.