This long awaited fourth volume of this important series is now available. The families reviewed are: Cerithiidae, Cerithiopsidae, Triphoridae, Rissoidae, Iravadiidae, Elachsinidae, Aporrhaidae, Hipponicidae, Vanikoridae, Haloceratidae, Capulidae, Velutinidae, Lamellariidae, Ovulidae, Naticidae, Laubierinidae, Ranillidae, Tonnidae, and Cassidae. All species are illustrated and described.