goose-necked barnacle Mitella pollicipes (formerly Pollicipes cornucopia), best known under its Spanish name, percebes, is a marine delicacy which is unknown in many countries but appreciated with enormous enthusiasm in others. It is a crustacean (not a mollusc, as one might think at first glance), but very different from creatures like crabs and prawns. Its classification as a crustacean was belated, since its internal structure was for long not understood. It is indeed puzzling; Huxley (1877) described the barnacle (not just this one but any) as ‘lying on its back, holding on by its head, and kicking its food into its mouth with its heels’.
