Cypraeidae  Cypraeidae, common name the cowries (singular: cowry), is a taxonomic family of small to large sea snails. These are marine gastropod mollusks in the superfamily Cypraeoidea, the cowries and cowry allies. Cypraeidae have adult shells which are very rounded, almost like an egg; they do not look like a typical gastropod shell. In virtually all of the species in the family Cypraeidae, the shells are extremely smooth and shiny. This is because in the living animal, the shell is nearly always fully covered with the mantle. Typically, no spire is visible in the fully adult shell, and there is a long, narrow, aperture which is lined with "teeth." Juvenile cowry shells are not at all similar to adult cowry shells. The juvenile shells of cowries perhaps more closely resemble the shells of some "bubble snails" in the order Cephalaspidea. Also the shells of juvenile cowries seldom exhibit the same color patterns as the adult shells do, and thus can be hard to identify to species. Cowries have no operculum. The very narrow toothed aperture of the cowry shell makes the adult shells difficult for many predators to reach into. However cowries are still vulnerable to predation:  The eating habits of cowries are poorly known, because most species are nocturnal and cryptic, but sponges are the most commonly described prey. Off the coasts of Australia, common cowry species eat sponges, and on Caribbean coral reefs they are known to eat sponges that are otherwise chemically defended against other predators. For nearly 200 years, every species in the family Cypraeidae was placed in one genus, "Cypraea", but in 2002  the cowries were divided into many different genera. The family Cypraeidae belongs, together with the family Ovulidae, to the superfamily Cypraeoidea. This, in turn, is part of the clade Littorinimorpha which belongs within the clade Hypsogastropoda according to the taxonomy of Bouchet & Rocroi (2005). The following six subfamilies have been recognized in the taxonomy of Bouchet & Rocroi (2005) but are treated as alternate representation of Cypraeidae in the World Register of Marine Species :  Genera within the family Cypraeidae include:     For a list of Species in the taxonomic family Cypraeidae, see Cowries.