Pagurus chiracanthus Aurivillius, 1891 – synonym of Anapagurus chiroacanthus
Pagurus chiroacantha Sars, 1872 – synonym of Anapagurus chiroacanthus
Pagurus chiroacanthus Lilljeborg, 1856 – synonym of Anapagurus chiroacanthus
Pagurus ferrugineus Norman, 1861 – synonym of Anapagurus chiroacanthus
Pagurus hyndmanni Bell, 1846 – synonym of Anapagurus hyndmanni
Pagurus hyndmanni Thompson, 1844 – synonym of Anapagurus hyndmanni
Palaemon fabricii Rathke, 1843 – synonym of Palaemon adspersus
Palaemon nitescens Leach, 1814 – synonym of Athanas nitescens
Panoploea eblanae Lincoln, 1979 – synonym of Iphimedia spatula
Paradoxostoma ensiforme Brady, 1868 – synonym of Paradoxostoma angliorum
Paradoxostoma hibernicum Brady & Norman, 1889 – synonym of Paradoxostoma sarniense
Paramphithoe bicuspis Sars, 1893 – synonym of Parapleustes bicuspis
Paramphithoe norvegica Bruzelius, 1859 – synonym of Apherusa jurinei
Paramysis spiritus (Norman, 1860) – synonym of Schistomysis spiritus
Parapodopsis cornuta Czerniavsky, 1882 – synonym of Mesopodopsis slabberi
Parapodopsis goesi Czerniavsky, 1882 – synonym of Mesopodopsis slabberi
Pararistes audouinianus Robertson, 1892 – synonym of Perrierella audouiniana
Paratanais algicola Harger, 1878 – synonym of Leptochelia savignyi
Paratanais Batei Sars, 1882 – synonym of Pseudoparatanais batei
Paratanais forcipatus Bate and Westwood, 1868 – synonym of Pseudoparatanais batei
Paratylus falcatus Sars, 1893 – synonym of Atylus falcatus
Paratylus swammerdami Sars, 1893 – synonym of Atylus swammerdami
Paratylus uncinatus Sars, 1895 – synonym of Atylus falcatus
Paratylus vedlomensis Sars, 1893 – synonym of Atylus vedlomensis
Pectenogammarus planicrurus Reid, 1944 – synonym of Echinogammarus planicrurus
Phaedra kinahani Bate, 1862 – synonym of Liljeborgia kinahani
Pherusa bicuspis Bate, 1862 – synonym of Apherusa cirrus
Pherusa borealis Boeck – synonym of Apherusa cirrus
Pherusa cirrus Bate, 1862 – synonym of Apherusa cirrus
Pherusa fucicola Bate, 1862 – synonym of Apherusa jurinei
Pherusa fucicola Leach, 1814 – synonym of Gammarella fucicola
Philocheras bispinosus – synonym of Pontophilus bispinosus
Philocheras trispinosus – synonym of Pontophilus trispinosus
Phoxocephalus chelatus Della Valle, 1893 – synonym of Parametaphoxus fultoni
Phoxocephalus fultoni Scott, 1890 – synonym of Parametaphoxus fultoni
Phoxocephalus oculatus Stebbing, 1888 – synonym of Paraphoxus oculatus
Phoxus holbölli Kröyer, 1842 – synonym of Phoxocephalus holbolli
Phoxus oculatus Sars, 1879 – synonym of Paraphoxus oculatus
Phoxus plumosus Bate, 1857 – synonym of Harpinia antennaria
Phryxus longibranchiata Bate & Westwood, 1868 – synonym of Pleurocrypta longibranchiata
Phthisica acaudata Reibisch, 1906 – synonym of Phtisica marina
Phtisica acaudata Tichy, 1911 – synonym of Phtisica marina
Phtisica antillensis @(@not Mayer@)@ Pequegnat, 1966 – synonym of Phtisica marina
Phtysica acaudata Borcea, 1934 – synonym of Phtisica marina
Phytisca marina Crawshay, 1912 – synonym of Phtisica marina
Pilumnopeus tridentatus Balss, 1933 – synonym of Rhithropanopeus harrisii
Pilumnus harrisii Gould, 1841 – synonym of Rhithropanopeus harrisii
Pilumnus tridentatus Maitland, 1874 – synonym of Rhithropanopeus harrisii
Pinnotheres cranchii Leach, 1815 – synonym of Pinnotheres pisum
Pinnotheres latreilli Leach, 1815 – synonym of Pinnotheres pisum
Pinnotheres montagui Leach, 1815 – synonym of Pinnotheres pinnotheres
Pinnotheres varians Leach, 1815 – synonym of Pinnotheres pisum
Pinnotheres veterum Leach, 1815 – synonym of Pinnotheres pinnotheres
Pirimela princeps Hope, 1851 – synonym of Pirimela denticulata
Planes linnaeana Leach, 1875 – synonym of Planes minutus
Platophium darwinii Stebbing, 1888 – synonym of Podocerus variegatus
Platycarcinus pagurus Couch, 1838 – synonym of Cancer pagurus
Platycarcinus pagurus H. Milne Edwards, 1834 – synonym of Cancer pagurus
Pleonexes gammaroides Bate, 1856 – synonym of Ampithoe gammaroides
Pleurocrypta galathea Hesse, 1865 – synonym of Pleurocrypta marginata
Podoceropsis excavata Sars, 1894 – synonym of Gammaropsis nitida
Podoceropsis nitida Stebbing, 1906 – synonym of Gammaropsis nitida
Podoceropsis nitidus Stimpson, 1853 – synonym of Gammaropsis nitida
Podoceropsis palmatus Stebbing and Robertson, 1891 – synonym of Gammaropsis palmata
Podocerus falcatus Bate, 1857d – synonym of Jassa falcata
Podocerus herdmani Walker, 1893a – synonym of Jassa herdmani
Podocerus ocius Bate, 1862 – synonym of Jassa ocia
Podocerus odontonyx Sars, 1894 – synonym of Jassa falcata
Podocerus valida Stebbing, 1888 – synonym of Jassa falcata
Podopsis slabberi Van Beneden, 1861 – synonym of Mesopodopsis slabberi
Pontocrates arenarius Norman and Scott, 1906 – synonym of Pontocrates altamarinus
Pontocrates longimanus – synonym of Perioculodes longimanus
Pontocypris pirifera G.W. Müller, 1894 – synonym of Propontocypris pirifera
Pontocypris serrulata Sars, 1866 – synonym of Pontocypris mytiloides
Pontocypris trigonella Brady & Norman, 1889 – synonym of Propontocypris pirifera
Pontocypris trigonella Brady, 1868 – synonym of Propontocypris trigonella
Portumnus nasutus Garstang, 1897 – synonym of Xaiva biguttata
Portumnus variegatus Leach, 1815 – synonym of Portumnus latipes
Portunus arcuatus Leach, 1814 – synonym of Liocarcinus arcuatus
Portunus barbarus Lucas, 1846 – synonym of Liocarcinus vernalis
Portunus biguttatus Risso, 1916 – synonym of Xaiva biguttata
Portunus corrugatus Leach, 1816 – synonym of Liocarcinus corrugatus
Portunus dalyellii Bate, 1851 – synonym of Bathynectes longipes
Portunus depurator Leach, 1815 – synonym of Liocarcinus depurator
Portunus diacantha Latreille, 1825 – synonym of Callinectes sapidus
Portunus dubius Rathke, 1837 – synonym of Liocarcinus vernalis
Portunus emarginatus Leach, 1816 – synonym of Liocarcinus arcuatus
Portunus Guttatus Risso, 1816 – synonym of Liocarcinus arcuatus
Portunus holsatus Fabricius, 1798 – synonym of Liocarcinus holsatus
Portunus lividus Leach, 1816 – synonym of Liocarcinus holsatus
Portunus longipes Risso, 1816 – synonym of Bathynectes longipes
Portunus macropipus Prestandrea, 1833 – synonym of Macropipus tuberculatus
Portunus maculatus Risso, 1827 – synonym of Liocarcinus pusillus
Portunus marmoreus Leach, 1814 – synonym of Liocarcinus marmoreus
Portunus parvulus Parisi, 1915 – synonym of Liocarcinus pusillus
Portunus plicatus Risso, 1816 – synonym of Liocarcinus depurator
Portunus puber Fabricius, 1798 – synonym of Necora puber
Portunus pusillus Leach, 1815 – synonym of Liocarcinus pusillus
Portunus pustulatus Norman, 1862 – synonym of Macropipus tuberculatus
Portunus Rondeleti Risso, 1816 – synonym of Liocarcinus arcuatus
Portunus tuberculatus Roux, 1830 – synonym of Macropipus tuberculatus
Portunus valentieni Cocco, 1833 – synonym of Liocarcinus vernalis
Portunus vernalis Risso, 1827 – synonym of Liocarcinus vernalis
Potocypris trigonella Sars, 1866 – synonym of Propontocypris trigonella
Praniza coeruleata Desm. – synonym of Gnathia maxillaris
Praniza Edwardii Bate – synonym of Gnathia maxillaris
Praunus integer Leach, 1814 – synonym of Neomysis integer
Probolium calcaratum Sars, 1882 – synonym of Proboloides calcarata
Probolium monoculoides Norman, 1869 – synonym of Stenothoe monoculoides
Probolium serratipes Norman, 1869 – synonym of Amphilochoides serratipes
Probolium spence-batei Stebbing, 1876 – synonym of Amphilochus spencebatei
Proboloides bruzelii Stebbing, 1906 – synonym of Metopa bruzelii
Propontocypris (Ekpontocypris) pirifera Maddocks, 1969 – synonym of Propontocypris pirifera
Protella phasma – synonym of Pseudoprotella phasma
Proto brunneovittata Haller, 1879 – synonym of Phtisica marina
Proto elongata Bate, 1862 – synonym of Phtisica marina
Proto elongatus Dana, 1853 – synonym of Phtisica marina
Proto goodsiri Stebbing, 1876 – synonym of Phtisica marina
Proto goodsirii Bate, 1856 – synonym of Phtisica marina
Proto pedata Leach, 1814 – synonym of Phtisica marina
Proto pedata White, 1850 – synonym of Phtisica marina
Proto pedatum W. Thornpson, 1944 – synonym of Phtisica marina
Proto pedatus Fleming, 1823 – synonym of Phtisica marina
Proto ventricosa Boeck, 1871 – synonym of Phtisica marina
Protomedeia hirsutimana Bate, 1862 – synonym of Leptocheirus hirsutimanus
Protomedeia longimana Boeck, 1871 – synonym of Megamphopus cornutus
Protomedeia pectinata Norman, 1869 – synonym of Leptocheirus pectinatus
Protomedeia pilosa Bate, 1862 – synonym of Leptocheirus pilosus
Protomedeia whitei Bate, 1862 – synonym of Cheirocratus sundevallii
Proton pedatum Desmarest, 1823 – synonym of Phtisica marina
Protosiriellis jaltensis (Czerniavsky, 1868) – synonym of Siriella jaltensis
Pseudocuma cercaria (Van Beneden, 1861) – synonym of Pseudocuma longicornis
Pseudosiriella frontalis Norman, 1886 – synonym of Siriella armata
Pseudotanais (Pseudotanais) forcipatus – synonym of Pseudotanais forcipatus
Pterygocera arenaria Bovallius, 1878 – synonym of Haustorius arenarius
Ptilocheirus hirsutimanus Chevreux, 1887 – synonym of Leptocheirus hirsutimanus
Ptilocheirus pectinatus Chevreux, 1887 – synonym of Leptocheirus pectinatus