Gastropoda
      Heterobranchia
            Opisthobranchia
                  Anaspidea
                              Aplysioidea
                                    Aplysiidae
                  Cephalaspidea
                              Acteonoidea
                                    Acteonidae
                                    Aplustridae
                                    Bullinidae
                              Bulloidea
                                    Bullidae
                              Cylindrobulloidea
                                    Cylindrobullidae
                              Diaphanoidea
                                    Diaphanidae
                              Haminoeoidea
                                    Haminoeidae
                                    Smaragdinellidae
                              Philinoidea
                                    Aglajidae
                                    Akeridae
                                    Cylichnidae
                                    Gastropteridae
                                    Philinidae
                                    Retusidae
                                    Scaphandridae
                  Gymnosomata
                              Clionoidea
                                    Clionidae
                                    Cliopsidae
                                    Pneumodermatidae
                  Nudibranchia
                              Aeolidioidea
                                    Aeolidiidae
                                    Facelinidae
                                    Favorinidae
                                    Flabellinidae
                                    Glaucidae
                              Arminoidea
                                    Arminidae
                              Dendronotoidea
                                    Dendronotidae
                                    Dotidae
                                    Embletoniidae
                                    Lomanotidae
                                    Tethyidae
                              Doridoidea
                                    Archidorididae
                                    Cadlinidae
                                    Chromodorididae
                                    Discodorididae
                                    Dorididae
                                    Geitodorididae
                                    Rostangidae
                              Fionoidea
                                    Fionidae
                                    Tergipedidae
                              Onchidoridoidea
                                    Corambidae
                                    Goniodorididae
                                    Onchidorididae
                              Phyllidioidea
                                    Dendrodorididae
                                    Phyllidiidae
                              Polyceroidea
                                    Gymnodorididae
                                    Hexabranchidae
                                    Polyceridae
                              Tritonioidea
                                    Bornellidae
                                    Phylliroidae
                                    Scyllaeidae
                                    Tethydidae
                                    Tritoniidae
                  Nudipleura
                              Pleurobranchoidea
                                    Pleurobranchidae
                  Sacoglossa
                              Elysioidea
                                    Caliphyllidae
                                    Elysiidae
                                    Stiligeridae
                              Julioidea
                                    Juliidae
                              Oxynooidea
                                    Oxynoidae
                                    Volvatellidae
                              Placobranchoidea
                                    Placobranchidae
                  Thecosomata
                              Cavolinioidea
                                    Cavoliniidae
                                    Limacinidae
                              Cymbulioidea
                                    Cymbuliidae
                                    Peraclidae