Lepas anatifera Linnaeus, 1758
This is not a Mollusc. Other non-Molluscan Phyla (Echinodermata, Brachiopoda etc) have been included to help identify species that may be mistaken for Mollusca, but are not.
Arthropoda (Phylum) > Crustacea (Subphylum) > Hexanauplia (Class) > Thecostraca (Subclass) > Lepadiformes (Order) > Lepadidae
(Family) > Lepas
(Genus) > Anatifa
(Subgenus) > anatifera (Species)