This book gives a comprehensive look at a single genus of small cowries that seem to show little morphological variation. It renders a detailed analysis of every aspect that the cowry shell itself may reveal about its builder. While the results for this particular genus show a surprising consistency with the results of molecular analysis, this study can serve as an example of cowry studies that incorporate both disciplines: a modern approach to conchology as well as genetic barcoding. The genus Pustularia (Gastropoda – Cypraeidae: Pustulariinae) has a wide distribution in the Indo-Pacific and the Red Sea. Lacking an older fossil history, it is difficult to relate the genus to any other living group of cowries. Its eighteen taxa can be hard to distinguish. The shells are characterized by the presence, reduction or absence of four key features of their coloration. More subtle structural features are used to distinguish between the subspecies. The distributions of the taxa in the Indo-Pacific are discussed. The secondary bilateral symmetry of the shell is a feature that characterizes many cowries, with Pustularia in particular. Discussions and descriptions of all species, subspecies and their variations will be given. Three new subspecies are described: bistrinotata excelsior, b. ginoi and chiapponii beatricae. More than 500 shells and numerous animals are shown in the color plates to illustrate the subtle beauty of this genus.