Phylum Mollusca Linnaeus, 1758 - molluscs Subphylum Conchifera Gegenbauer, 1878 Class Gastropoda Cuvier, 1795 - snails and slugs Subclass Orthogastropoda Ponder & Lindberg, 1995 Superorder Cocculiniformia Haszprunar, 1987 see Superfamily Cocculinoidea Dall, 1882 Superfamily Lepetelloidea Dall, 1882 Family Addisoniidae Dall, 1882 Subfamily Helicopeltinae Marshall, 1996