Phylum Chordata Bateson, 1885 - chordates Subphylum Vertebrata Cuvier, 1812 - vertebrates see Infraphylum Vertebrata Lamarck, 1801 Class Cephalaspidomorpha see Class Cephalaspidomorphi Kiaer & Stensiö, 1920 Order Petromyzontiformes Berg, 1940 - lampreys Family Petromyzontidae Bonaparte, 1831 - lampreys Genus Lampetra Bonnaterre, 1788 Genus Lethenteron Creaser & Hubbs, 1922 Genus Petromyzon Linnaeus, 1758