This book is a portrait of the Gastropod family Xenophoridae: marine snails with the peculiar behaviour of attaching foreign objects to their shells. Their name is derived from Greek Xenos = foreign and phoros = carrier. Carrier shells have inhabited the sea floors of tropical and subtropical oceans for eons, recycling empty shells of molluscs, as wel as pieces of dead corals, stones, sunken wood, coal, and even teeth shed by sharks. Only very recently, broken glass, coins, bottle caps, can openers, and pieces of plastic appeared in their environments; things produced and dumped in the sea by man.