| [24497] Alitta | Appellations de Taxon | 24497 |
| [24498] Alsidium | Appellations de Taxon | 24498 |
| [24499] Ampharete agulhasensis | Appellations de Taxon | 24499 |
| [245] Tinodes | Appellations de Taxon | 245 |
| [2450] Hydroporus ferrugineus | Appellations de Taxon | 2450 |
| [24500] Amphilochidae | Appellations de Taxon | 24500 |
| [24501] Amphinomidae | Appellations de Taxon | 24501 |
| [24502] Amphipholis | Appellations de Taxon | 24502 |
| [24503] Amphitrite | Appellations de Taxon | 24503 |
| [24504] Amphiura | Appellations de Taxon | 24504 |
| [24505] Ancistrosyllis | Appellations de Taxon | 24505 |
| [24506] Anemonia viridis | Appellations de Taxon | 24506 |
| [24507] Anoplodactylus petiolatus | Appellations de Taxon | 24507 |
| [24508] Anoplodactylus pygmaeus | Appellations de Taxon | 24508 |
| [24509] Anoplodactylus virescens | Appellations de Taxon | 24509 |
| [2451] Hydroporus incognitus | Appellations de Taxon | 2451 |
| [24510] Anthura gracilis | Appellations de Taxon | 24510 |
| [24511] Antithamnionella | Appellations de Taxon | 24511 |
| [24512] Aora gracilis | Appellations de Taxon | 24512 |
| [24513] Aphelochaeta filiformis | Appellations de Taxon | 24513 |
| [24514] Aphelochaeta marioni | Appellations de Taxon | 24514 |
| [24515] Apoglossum | Appellations de Taxon | 24515 |
| [24516] Aponuphis | Appellations de Taxon | 24516 |
| [24517] Apseudinae | Appellations de Taxon | 24517 |
| [24518] Arabella | Appellations de Taxon | 24518 |
| [24519] Arcturella danmoniensis | Appellations de Taxon | 24519 |
| [2452] Hydroporus longulus | Appellations de Taxon | 2452 |
| [24521] Arenicola marina | Appellations de Taxon | 24521 |
| [24522] Arenicolides grubii | Appellations de Taxon | 24522 |
| [24523] Argissidae | Appellations de Taxon | 24523 |
| [24524] Aricia | Appellations de Taxon | 24524 |
| [24525] Aricidea (Acmira) | Appellations de Taxon | 24525 |
| [24526] Aricidea minuta | Appellations de Taxon | 24526 |
| [24527] Armandia cirrhosa | Appellations de Taxon | 24527 |
| [24528] Armandia polyophthalma | Appellations de Taxon | 24528 |
| [24529] Ascophyllum nodosum | Appellations de Taxon | 24529 |
| [2453] Hydroporus marginatus | Appellations de Taxon | 2453 |
| [24530] Aspidosiphonida | Appellations de Taxon | 24530 |
| [24531] Asterias rubens | Appellations de Taxon | 24531 |
| [24532] Asterina gibbosa | Appellations de Taxon | 24532 |
| [24533] Aulactinia verrucosa | Appellations de Taxon | 24533 |
| [24534] Aureliana heterocera | Appellations de Taxon | 24534 |
| [24535] Autonoe | Appellations de Taxon | 24535 |
| [24536] Axelsonia | Appellations de Taxon | 24536 |
| [24537] Bela nebula | Appellations de Taxon | 24537 |
| [24538] Blidingia | Appellations de Taxon | 24538 |
| [24539] Boccardia redeki | Appellations de Taxon | 24539 |
| [2454] Hydroporus melanarius | Appellations de Taxon | 2454 |
| [24540] Bodotria scorpioides | Appellations de Taxon | 24540 |
| [24541] Bonnemaisoniaceae | Appellations de Taxon | 24541 |