316 species from the tropical Indo-Pacific, including subspecies and forms, are illustrated and discussed in detail. 2,500+ shells are illustrated on 84 color plates, including 8 plates of living animals. Information for each species includes synonyms, homonyms, status of type specimen, type locality, distribution map, discussion with description and differentiation from similar species, and summary of appearance, radula, habits and habitats of the living animal. Included are SEM photographs of radulae and protoconchs, information on biology, ecology and zoogeography, and 170 figures and maps.