A Scallop seashell. Scallops are saltwater clams or bivalves in the family Pectinidae. The elegant fan shape is an iconic image of marine life.
The shell of the European edible sea urchin (Echinus esculentus), family Echinoidea. Sea urchins move slowly, feeding primarily on algae.
A Schilder's Tiger cowrie sea shell (Cyprae tigris f, shilderiana). These are large sea snails, marine gastropod molluscs in the family Cypraeidae. The beautiful porcelain-like shells are often used in jewelry.