It has commonly been assumed that the terebratuloid and rhynchonelloid brachiopods found in Mesozoic and Tertiary formations are entombed on the site of growth. Recent work on members of the genus Hamptonina from the Great Oolite (Jurassic) at Bath (England), and a study of the literature on other localities lead to the conclusion that these brachiopod shells have often been transported by marine currents after the death of the organism.