Helicinoidea
                                    Helicinidae
                                    Neritilidae
                                    Proserpinellidae
                                    Proserpinidae
                              Hydrocenoidea
                                    Hydrocenidae
                              Neritoidea
                                    Neritidae
                                    Phenacolepadidae
                              Neritopsoidea
                                    Neritopsidae