Abstract
Botula cinnamomea ,Gregariella coralliophaga and three species of Lithophaga were found in large blocks of Porites. Lithophaga teres occurred predominantly in the lower side of the blocks, whereas the other species were found mainly in the upper side. The well-developed anterior pallial folds and the unscratched shells of Botula and Gregariella indicate that also these species bore chemically.