Rachel Carson, now better known for blowing the whistle on pesticides than for her revelatory books about the sea, once tried to buy the only specimen of the pelagic violet snail Janthina in a shell shop in North Carolina. Rebuffed, she waited on luck, and ‘later I found an empty shell, light as thistledown, resting in a depression in the coral rock of Key Largo, where some gentle tide had laid it’ (Carson 1955). Reading this, I felt the beachcomber’s moment of uplift, not least from having come upon two of these beautiful shells, resting within a pace of each other on the sandy tideline below my home on the Mayo coast.
