| Pachycardium | Protocardiinae | Cardiidae | Cardioidea | Plesiocerithium | Cancellariinae | Cancellariidae | Mitroidea | |
| Pachycrommium | Ampullospirinae | Ampullinidae | Naticoidea | Plesiothyreus | Phenacolepadidae | Neritoidea | ||
| Pachymelon | Zidoninae | Volutidae | Volutoidea | Plesiotriton | Admetinae | Cancellariidae | Mitroidea | |
| Paladmete | Cancellariinae | Cancellariidae | Mitroidea | Plesiotriton | Cymatinae | Ranellidae | Tonnoidea | |
| Palaeocyclophorus | Cyclophorinae | Cyclophoridae | Cyclophoroidea | Pleurodesma | Pleurodesmatidae | Myoidea | ||
| Palaeocypraea | Bernayinae | Cypraeidae | Cypraeoidea | Pleurofusia | Crassispirinae | Turridae | Conoidea | |
| Palaeophaedusa | Phaedusinae | Clausiliidae | Clausilioidea | Pleuroliria | Turrinae | Turridae | Conoidea | |
| Palaeostoa | Megomphycidae | Mesurethra | Pleuromeris | Carditamerinae | Carditidae | Carditoidea | ||
| Paleopsephaea | Fasciolariinae | Fasciolariidae | Columbelloidea | Pleuromya | Pholadomyidae | Pholadomyoidea | ||
| Palindonaia | Unioninae | Unionidae | Unionoidea | Pleuroploca | Fasciolariinae | Fasciolariidae | Columbelloidea | |
| Pallacera | Nassariinae | Nassariidae | Buccinoidea | Pleurotomella | Daphnellinae | Conidae | Conoidea | |
| Palliolum | Palliolinae | Pectinidae | Pectinoidea | Pleurotomoides | Subfamily uncertain | Conidae | Conoidea | |
| Panamurex | Muricinae | Muricidae | Muricoidea | Plicatula | Plicatulidae | Plicatuloidea | ||
| Pandora | Pandoridae | Pandoroidea | Plicifusus | Buccininae | Buccinidae | Buccinoidea | ||
| Panopea | Hiatellidae | Hiatelloidea | Pliciscala | Epitoniinae | Epitoniidae | Janthinoidea | ||
| Paphia | Tapetinae | Veneridae | Veneroidea | Plicobulla | Cylichnidae | Acteonoidea | ||
| Papyridea | Trachycardiinae | Cardiidae | Cardioidea | Pododesmus | Anomiidae | Anomioidea | ||
| Paraglans | Carditesinae | Carditidae | Carditoidea | Poirieria | Muricinae | Muricidae | Muricoidea | |
| Paralucina | Lucininae | Lucinidae | Lucinoidea | Polinices | Polinicidae | Naticoidea | ||
| Paralucinella | Divaricellinae | Lucinidae | Lucinoidea | Pollia | Pisaniinae | Buccinidae | Buccinoidea | |
| Parametaria | Pyreninae | Columbellidae | Columbelloidea | Polygireulima | Eulimidae | Eulimoidea | ||
| Paramonopleura | Monopleuridae | Hippuritoidea | Polymesoda | Corbiculidae | Corbiculoidea | |||
| Parapholas | Martesiinae | Pholadidae | Pholadoidea | Polystira | Turrinae | Turridae | Conoidea | |
| Paraseraphs | Seraphsidae | Stromboidea | Pomacea | Pilidae | Ampullarioidea | |||
| Parastarte | Gemminae | Veneridae | Veneroidea | Ponderia | Tripterotyphinae | Muricidae | Muricoidea | |
| Parasyrinx | Cochlespirinae | Turridae | Conoidea | Poromya | Poromyidae | Poromyoidea | ||
| Paratrophon | Trphoninae | Muricidae | Muricoidea | Porterius | Grammatodontinae | Paralellodontidae | Arcoidea | |
| Pareuchelus | Turbininae | Turbinidae | Trochoidea | Portlandia | Yoldiellinae | Yoldiidae | Nuculanoidea | |
| Parvicardium | Cardiinae | Cardiidae | Cardioidea | Potamides | Potamininae | Potamididae | Cerithioidea | |
| Parviconus | Coninae | Terebridae | Conoidea | Potamocorbula | Corbulinae | Corbulidae | Myoidea | |
| Parvilucina | Lucininae | Lucinidae | Lucinoidea | Priscoficus | Ficidae | Ficoidea | ||
| Parvisipho | Buccininae | Buccinidae | Buccinoidea | Proadusta | Erosariinae | Cypraeidae | Cypraeoidea | |
| Paryphanta | Rhytidae | Rhytidoidea | Projenneria | Ovulinae | Ovulidae | Cypraeoidea | ||
| Paryphostoma | Rissoininae | Rissoinidae | Rissooidea | Propeamussium | Propeamussiidae | Pectinoidea | ||
| Patella | Patellinae | Patellidae | Patelloidea | Propefusus | Fusininae | Fasciolariidae | Columbelloidea | |
| Patelloida | Patelloidinae | Lottidae | Patelloidea | Propustularia | Erosariinae | Cypraeidae | Cypraeoidea | |
| Patinopecten | Patinopectinae | Pectinidae | Pectinoidea | Proterato | Eratoidae | Xenophoroidea | ||
| Patro | Anomiidae | Anomioidea | Protobusycon | Busyconinae | Melongenidae | Buccinoidea | ||
| Pauraudeautia | Polinicidae | Naticoidea | Protoginella | Marginellinae | Marginellidae | Volutoidea | ||
| Paziella | Muricinae | Muricidae | Muricoidea | Protoma | Protominae | Turritellidae | Cerithioidea | |
| Peasiella | Risellinae | Littorinidae | Littorinoidea | Protosurcula | Cochlespirinae | Turridae | Conoidea | |
| Pecten | Pectininae | Pectinidae | Pectinoidea | Protothaca | Chioninae | Veneridae | Veneroidea | |
| Pector | Subfamily uncertain | Pectinidae | Pectinoidea | Prunum | Marginellinae | Marginellidae | Volutoidea | |
| Pectunculina | Limopsidae | Limopsoidea | Psammodonax | Psammobiinae | Psammobiidae | Tellinoidea | ||
| Pegosyphema | Milthinae | Lucinidae | Lucinoidea | Psathura | Clementiniinae | Veneridae | Veneroidea | |
| Pelecyora | Pitarinae | Veneridae | Veneroidea | Pseudamaura | Ampullospirinae | Ampullinidae | Naticoidea | |
| Pelicaria | Struthiolariidae | Stromboidea | Pseudamussium | Pectininae | Pectinidae | Pectinoidea | ||
| Penicillus | Clavagellidae | Clavagelloidea | Pseudantalis | Dentaliidae | Dentaliida | Scaphopoda | ||
| Penion | Buccininae | Buccinidae | Buccinoidea | Pseudaucella | Buchiidae | Pectinoidea | ||
| Periglypta | Venerinae | Veneridae | Veneroidea | Pseudoaluco | Cerithiinae | Cerithiidae | Cerithioidea | |
| Peringia | Hydrobiinae | Hydrobiidae | Rissooidea | Pseudoandonia | Siphopsinae | Conidae | Conoidea | |
| Periploma | Periplomatidae | Pandoroidea | Pseudobellardia | Melanopsidae | Cerithioidea | |||
| Periplomya | Laternulidae | Pandoroidea | Pseudocardium | Mactrinae | Mactridae | Mactroidea | ||
| Perissoptera | Aporrhaiidae | Stromboidea | Pseudochama | Chamidae | Chamoidea | |||
| Peristernia | Peristerniinae | Fasciolariidae | Columbelloidea | Pseudocirsope | Elachisinidae | Rissooidea | ||
| Perna | Mytilinae | Mytilidae | Mytiloidea | Pseudocominella | Dorsaninae | Nassariidae | Buccinoidea | |
| Peronaea | Tellininae | Tellinidae | Tellinoidea | Pseudocypraea | Ovulinae | Ovulidae | Cypraeoidea | |
| Perplicaria | Cancellariinae | Cancellariidae | Mitroidea | Pseudogrammoceras | Hildoceratidae | Ammonoida | ||
| Perrona | Clavatulinae | Turridae | Conoidea | Pseudoischnochiton | Helminthochitoninae | Leptochitonidae | Lepidopleurina | |
| Persicula | Persiculinae | Cystiscidae | Volutoidea | Pseudolepton | Kelliinae | Kelliidae | Galeommatoidea | |
| Peseudotaphrus | Rissoininae | Rissoinidae | Rissooidea | Pseudoliva | Pseudolividae | Buccinoidea | ||
| Petalocardia | Glossidae | Glossoidea | Pseudomalaxis | Heliacinae | Architectonicidae | Architectonicoidea | ||
| Petaloconchus | Vermetidae | Vermetoidea | Pseudomelania | Pseudomelaniidae | Cerithioidea | |||
| Petricola | Petricolidae | Veneroidea | Pseudomiltha | Milthinae | Lucinidae | Lucinoidea | ||
| Petricolaria | Petricolidae | Veneroidea | Pseudoneptunea | Buccininae | Buccinidae | Buccinoidea | ||
| Phacoides | Lucininae | Lucinidae | Lucinoidea | Pseudonina | Colloniinae | Turbinidae | Trochoidea | |
| Phacosoma | Dosininae | Veneridae | Veneroidea | Pseudopecten | Subfamily unknown | Pectinidae | Pectinoidea | |
| Phalium | Phaliinae | Cassidae | Tonnoidea | Pseudoportlandia | Yoldiellinae | Yoldiidae | Nuculanoidea | |
| Pharus | Cutellinae | Pharidae | Tellinoidea | Pseudotaphrus | Rissoininae | Rissoinidae | Rissooidea | |
| Phasianella | Phasianellinae | Turbinidae | Trochoidea | Pseudotoma | Incertae Sedis | Conidae | Conoidea | |
| Phaxas | Cutellinae | Pharidae | Tellinoidea | Pseudovertagus | Cerithiinae | Cerithiidae | Cerithioidea | |
| Phenacolepas | Phenacolepadidae | Neritoidea | Psilaxis | Heliacinae | Architectonicidae | Architectonicoidea | ||
| Phenatoma | Clathurellinae | Conidae | Conoidea | Pteria | Pteriidae | Pterioidea | ||
| Philbertia | Raphitominae | Conidae | Conoidea | Pterocerella | Strombinae | Strombidae | Stromboidea | |
| Philine | Philinidae | Acteonoidea | Pterochelus | Muricinae | Muricidae | Muricoidea | ||
| Philippia | Heliacinae | Architectonicidae | Architectonicoidea | Pterolucina | Milthinae | Lucinidae | Lucinoidea | |
| Phlyctiderma | Lyonsiidae | Pandoroidea | Pteromeris | Miodomeridinae | Carditidae | Carditoidea | ||
| Pholadidea | Martesiinae | Pholadidae | Pholadoidea | Pteropurpura | Ocenebrinae | Muricidae | Muricoidea | |
| Pholadomya | Pholadomyidae | Pholadomyoidea | Pterotyphisa | Tripterotyphinae | Muricidae | Muricoidea | ||
| Pholadopsis | Jouannetiinae | Pholadidae | Pholadoidea | Pterotytis | Ocenebrinae | Muricidae | Muricoidea | |
| Pholas | Pholadinae | Pholadidae | Pholadoidea | Pterotrigonia | Trigoniidae | Trigonioidea | ||
| Phorculus | Trochinae | Cirridae | Cirroidea | Pterotyphis | Tripterotyphinae | Muricidae | Muricoidea | |
| Phos | Photinae | Buccinidae | Buccinoidea | Pterynopsis | Trophoninae | Muricidae | Muricoidea | |
| Phyllonotus | Muricinae | Muricidae | Muricoidea | Pterynotus | Muricinae | Muricidae | Muricoidea | |
| Physa | Physidae | Physoidea | Ptychatractus | Ptychatractidae | Muricoidea | |||
| Pileolus | Neritiinae | Neritidae | Neritoidea | Ptychomya | Ptychomyidae | Arcticoidea | ||
| Pillucina | Lucininae | Lucinidae | Lucinoidea | Ptychosalpinx | Buccininae | Buccinidae | Buccinoidea | |
| Pinctada | Pteriidae | Pterioidea | Pucturella | Emarginulinae | Fissurellidae | Fissurelloidea | ||
| Pinna | Pinnidae | Pinnoidea | Pugilina | Melongeninae | Melongenidae | Buccinoidea | ||
| Pirenella | Potamininae | Potamididae | Cerithioidea | Pugnellus | Strombinae | Strombidae | Stromboidea | |
| Pisanella | Cancellariinae | Cancellariidae | Mitroidea | Pulsellum | Pulsellidae | Gadilimorpha | Scaphopoda | |
| Pisania | Pisaniinae | Buccinidae | Buccinoidea | Purpura | Rapaninae | Muricidae | Muricoidea | |
| Pisidium | Pisidiidae | Corbiculoidea | Purpurellus | Muricinae | Muricidae | Muricoidea | ||
| Pisinna | Anabathridae | Rissooidea | Pusila | Trividae | Lamellarioidea | |||
| Pitar | Pitarinae | Veneridae | Veneroidea | Pusillina | Rissoinae | Rissoidae | Rissooidea | |
| Pitharella | Acteoninae | Acteonidae | Acteonoidea | Pusionella | Clavatulinae | Turridae | Conoidea | |
| Placamen | Chioninae | Veneridae | Veneroidea | Pustularia | Erosariinae | Cypraeidae | Cypraeoidea | |
| Placunanomia | Placunidae | Anomioidea | Pycnodonte | Pycnodonteinae | Gryphaeidae | Ostreoidea | ||
| Plagiocardium | Cardiinae | Cardiidae | Cardioidea | Pygocardia | Arcticidae | Arcticoidea | ||
| Planaxis | Planaxidae | Cerithioidea | Pyramidella | Pyramidellinae | Pyramidellidae | Pyramidelloidea | ||
| Planikellia | Erycininae | Lasaeidae | Galeommatoidea | Pyrazisinus | Potamininae | Potamididae | Cerithioidea | |
| Planorbarius | Helisomatinae | Planorbidae | Planorbioidea | Pyrazus | Potamininae | Potamididae | Cerithioidea | |
| Planorbis | Planorbinae | Planorbidae | Planorbioidea | Pyrifusus | Busyconinae | Melongenidae | Buccinoidea | |
| Platyphysa | Physidae | Physoidea | Pyropsis | Vasidae | Turbinelloidea | |||
| Plectodon | Cuspidariidae | Cuspidariina | Pyruclia | Cancellariinae | Cancellariidae | Mitroidea | ||
| Pleia | Fasciolariinae | Fasciolariidae | Columbelloidea | Pyruella | Busyconinae | Melongenidae | Buccinoidea | |
| Pleiotygma | Scaphellinae | Volutidae | Volutoidea | Pythia | Ellobiinae | Ellobiidae | Ellobioidea | |
| Plejona | Volutinae | Volutidae | Volutoidea | Pythina | Lsaeinae | Lasaeidae | Galeommatoidea | |
| Plesiastarte | Gemminae | Veneridae | Veneroidea | Pythiopsis | Ellobiinae | Ellobiidae | Ellobioidea | |