Strictly, the name should refer only to those bivalves which can close their hinged shells completely, since it is derived from the verb clam, meaning shut. On this basis, almost all bivalves would qualify as clams; although, paradoxically, the soft-shelled clam and the razor clam would not, since their shells always gape open slightly. In practice, however, those bivalves which are very well known and have their own names, for example the oyster and the mussel, are rarely referred to as clams. And the name is used so much more in N. America than in Britain that some British people have the impression that clams are an American phenomenon. In fact, the clams which are eaten with such gusto in N. America exist also on the European side of the Atlantic; but they are rarely consumed in Britain or other countries to the north of France, although a start has been made in cultivating some species on the south coast of England and it is reasonable to suppose that the American pattern of consumption will eventually be replicated in NW Europe. Meanwhile it is of interest that the French reserve their word ‘clam’ for the species called quahog in N. America.