Psa
- Psachonethes
- Psalidopodidae
- Psalidopodoidea
- Psalidopus
- Psammameira
- Psammasellus
- Psammastacus
- Psammis
- Psammocamptus
- Psammocyclopinidae
- Psammocyclopinidae
- Psammocythere
- Psammocytheridae
- Psammocytheridae
- Psammokalliapseudes
- Psammolaophonte
- Psammonitocrella
- Psammonyx
- Psammopsyllus
- Psammotopa
- Psathyrocaris
- Psaumis
Pse
- Pseudactaea
- Pseudactumnus
- Pseudaega
- Pseudaeginella
- Pseudambasia
- Pseudamblyops
- Pseudameira
- Pseudamphiascopsis
- Pseudanchialina
- Pseudanthessiidae
- Pseudanthessiidae
- Pseudanthessius
- Pseudanthura
- Pseudanuretes
- Pseudarachna
- Pseudarcturella
- Pseudaristeus
- Pseudarmadillo
- Pseudaugaptilus
- Pseudectinosoma
- Pseuderythrops
- Pseudeuchaeta
- Pseudeuphausia
- Pseudevadne
- Pseudhaloptilus
- Pseudharpinia
- Pseudidothea
- Pseudidotheidae
- Pseudione
- Pseudionella
- Pseudo
- Pseudoaethiopopactes
- Pseudoagnara
- Pseudoamallothrix
- Pseudoamphithoides
- Pseudoapseudes
- Pseudoapseudomorpha
- Pseudoarthrura
- Pseudobathytanais
- Pseudobradya
- Pseudobuddelundiella
- Pseudocalanus
- Pseudocaligus
- Pseudocandona
- Pseudocarcinus
Pseudocerceis Harrison & Holdich, 1982
- Pseudocerceis furculata Harrison & Holdich, 1982
- Pseudocerceis latistylis Kensley & Schotte, 1994
- Pseudocerceis seleneides Messana, 1988
- Pseudocerceis trilobata (Baker, 1908)
Crustacea → Malacostraca → Isopoda → Sphaeromatoidea → Sphaeromatidae
- Pseudocervinia
- Pseudochalaraspidum
- Pseudocharopinus
- Pseudocheles
- Pseudochirella
- Pseudochondracanthus
- Pseudochydorus
- Pseudocleta
- Pseudocletodes
- Pseudocletopsyllis
- Pseudoconchoecia
- Pseudocorystes
- Pseudocoutierea
- Pseudocrangonyctidae
- Pseudocrangonyx
- Pseudocryptochirus
- Pseudocryptocoeloma
- Pseudoctomeris
- Pseudocuma
- Pseudocumatidae
- Pseudocyclaspis
- Pseudocyclopia
- Pseudocyclopidae
- Pseudocyclopidae
- Pseudocyclopiidae
- Pseudocyclopiidae
- Pseudocyclops
- Pseudocycnidae
- Pseudocycnidae
- Pseudocycnoides
- Pseudocycnus
- Pseudocythere
- Pseudocytheretta
- Pseudodiaptomidae
- Pseudodiaptomidae
- Pseudodiaptomus
- Pseudodiastylis
- Pseudodiocus
- Pseudodiosaccopsis
- Pseudodiploexochus
- Pseudodromia
- Pseudoeucanthus
- Pseudogaetice
- Pseudogelasimus
- Pseudograpsus
- Pseudohalmyrapseudes
- Pseudohapalocarcinus
- Pseudohaustorius
- Pseudohelice
- Pseudohexapus
- Pseudoilyocypris
- Pseudoirona
- Pseudojanira
- Pseudojaniridae
- Pseudolambrus
- Pseudolamprops
- Pseudolana
- Pseudolaophonte
- Pseudolaureola
- Pseudolepeophtheirus
- Pseudoleptochelia
- Pseudoleptocuma
- Pseudoleptognathia
- Pseudoleptomesochra
- Pseudoleptomesochrella
- Pseudolernaeopodina
- Pseudoleucon
- Pseudoliomera
- Pseudoliropus
- Pseudolitochira
- Pseudolobodillo
- Pseudolubbockia
- Pseudolycaea
- Pseudomacrinella
- Pseudomedaeus
- Pseudomesochra
- Pseudomesus
- Pseudomicippe
- Pseudomimonectes
- Pseudomma
- Pseudomoina
- Pseudomonospilus
- Pseudomunida
- Pseudomunnopsis
- Pseudomyicola
- Pseudomyra
- Pseudomysidetes
- Pseudomysis
- Pseudonebaliopsis
- Pseudonototanais
- Pseudonsiella
- Pseudonychocamptus
- Pseudopalicus
- Pseudoparatanais
- Pseudopenilia
- Pseudopeniliidae
- Pseudopetalophthalmus
- Pseudophaenna
- Pseudophilomedes
- Pseudophiloscia
- Pseudophilyra
- Pseudopinnixa
- Pseudopleonexes
- Pseudopolycope
- Pseudopontonides
- Pseudoprotomima
- Pseudorhombila
- Pseudorhombilidae
- Pseudorthometopon
- Pseudosesarma
- Pseudosetaphora
- Pseudosida
Pseudosphaeroma Chilton, 1909
- Pseudosphaeroma barnardi Monod, 1931
- Pseudosphaeroma callidum Hurley & Jansen, 1977
- Pseudosphaeroma campbellense Chilton, 1909
- Pseudosphaeroma jakobii Loyola e Silva, 1959
- Pseudosphaeroma lundae (Menzies, 1962)
- Pseudosphaeroma platense (Giambiagi, 1922)
- Pseudosphaeroma tuberculatum (Sivertsen & Holthuis, 1980)
Crustacea → Malacostraca → Isopoda → Sphaeromatoidea → Sphaeromatidae
- Pseudosphyrapus
- Pseudosquilla
- Pseudosquillidae
- Pseudosquillisma
- Pseudosquillopsis
- Pseudostegias
- Pseudostenhelia
- Pseudosympodomma
- Pseudotachidiidae
- Pseudotachidiidae
- Pseudotachidius
- Pseudotaeniacanthus
- Pseudotanaidae
- Pseudotanais
- Pseudothalestris
- Pseudotharybis
- Pseudothelphusa
- Pseudothelphusidae
- Pseudothelphusoidea
- Pseudotiron
- Pseudotyphloscia
- Pseudowhiteleggia
- Pseudoxomysis
- Pseudozeuxidae
- Pseudozeuxo
- Pseudoziidae
- Pseudozimmeriana
- Pseudozioidea
- Pseudozius
- Pseudozosime
Pseudunciola Bousfield, 1973
- Pseudunciola obliquua (Shoemaker, 1949)
Crustacea → Malacostraca → Amphipoda → Corophiidira → Aoroidea → Unciolidae → Unciolinae
Psi
- Psittanthura
- Psittocythere
Pso
- Psopheticoides
- Psopheticus
Psy
- Psyllocamptus