| [23986] Ampelisca | Appellations de Taxon | 23986 |
| [23987] Ampharete acutifrons | Appellations de Taxon | 23987 |
| [23988] Ampharete baltica | Appellations de Taxon | 23988 |
| [23989] Amphicteis gunneri | Appellations de Taxon | 23989 |
| [2399] Gyrinus dejeani | Appellations de Taxon | 2399 |
| [23990] Amphidomataceae | Appellations de Taxon | 23990 |
| [23991] Amphiglena mediterranea | Appellations de Taxon | 23991 |
| [23992] Amphitritides gracilis | Appellations de Taxon | 23992 |
| [23993] Ampithoe | Appellations de Taxon | 23993 |
| [23994] Antalis | Appellations de Taxon | 23994 |
| [23995] Anthuridae | Appellations de Taxon | 23995 |
| [23996] Aonides oxycephala | Appellations de Taxon | 23996 |
| [23997] Aonides paucibranchiata | Appellations de Taxon | 23997 |
| [23998] Aora typica | Appellations de Taxon | 23998 |
| [23999] Aphrodita aculeata | Appellations de Taxon | 23999 |
| [24] Amphinemura sulcicollis | Appellations de Taxon | 24 |
| [240] Psychomyia pusilla | Appellations de Taxon | 240 |
| [2400] Gyrinus distinctus | Appellations de Taxon | 2400 |
| [24000] Aphroditiformia | Appellations de Taxon | 24000 |
| [24001] Apseudoidea | Appellations de Taxon | 24001 |
| [24002] Archaeobalaninae | Appellations de Taxon | 24002 |
| [24003] Arcturidae | Appellations de Taxon | 24003 |
| [24004] Arenicolidae | Appellations de Taxon | 24004 |
| [24005] Ascidia mentula | Appellations de Taxon | 24005 |
| [24006] Dytiscus dimidiatus | Appellations de Taxon | 24006 |
| [24008] Halesus radiatus | Appellations de Taxon | 24008 |
| [24009] Potamophylax luctuosus | Appellations de Taxon | 24009 |
| [2401] Gyrinus minutus | Appellations de Taxon | 2401 |
| [24010] Abludomelita gladiosa | Appellations de Taxon | 24010 |
| [24011] Abludomelita obtusata | Appellations de Taxon | 24011 |
| [24012] Acetabularia | Appellations de Taxon | 24012 |
| [24013] Acidostoma | Appellations de Taxon | 24013 |
| [24014] Acmaeidae | Appellations de Taxon | 24014 |
| [24015] Acteon tornatilis | Appellations de Taxon | 24015 |
| [24016] Aeolidioidea | Appellations de Taxon | 24016 |
| [24017] Akera bullata | Appellations de Taxon | 24017 |
| [24018] Ampelisca armoricana | Appellations de Taxon | 24018 |
| [24019] Ampelisca brevicornis | Appellations de Taxon | 24019 |
| [2402] Gyrinus paykulli | Appellations de Taxon | 2402 |
| [24020] Ampelisca diadema | Appellations de Taxon | 24020 |
| [24021] Ampelisca gibba | Appellations de Taxon | 24021 |
| [24022] Ampelisca sarsi | Appellations de Taxon | 24022 |
| [24023] Ampelisca spinimana | Appellations de Taxon | 24023 |
| [24024] Ampelisca spinipes | Appellations de Taxon | 24024 |
| [24025] Ampelisca tenuicornis | Appellations de Taxon | 24025 |
| [24026] Ampelisca typica | Appellations de Taxon | 24026 |
| [24027] Amphiuridae | Appellations de Taxon | 24027 |
| [24028] Ampithoe gammaroides | Appellations de Taxon | 24028 |
| [24029] Ampithoe helleri | Appellations de Taxon | 24029 |
| [2403] Gyrinus substriatus | Appellations de Taxon | 2403 |