Nanomia cara – synonym of Nanomia cara
Nauphantha celox – synonym of Alciopa reynaudii
Nematodactylus boopis – synonym of Nematobrachion boopis
Nematopus elegans – synonym of Erythrops elegans
Nematopus goessi – synonym of Erythrops erythrophthalma
Nematopus microps – synonym of Erythrops microps
Nematopus obesus – synonym of Parerythrops obesa
Nematopus serratus – synonym of Erythrops serrata
Nemopsis hetronema – synonym of Bougainvillia principis
Neomysis longicornis – synonym of Acanthomysis longicornis
Neomysis vulgaris – synonym of Neomysis integer
Nereis conchilega – synonym of Lanice conchilega
Nereis cylindraria belgica – synonym of Pectinaria belgica
Numerous other synonyms. – synonym of Liriope tetraphylla
Nyctiphanes (?) latifrons – synonym of Nyctiphanes couchi
Nyctiphanes couchii – synonym of Nyctiphanes couchi
Nyctiphanes norvegica – synonym of Meganyctiphanes norvegica