Cute Young Brunette Girl Reveals On The Beach With A Seashell

The term seashell usually refers to the exoskeleton of an invertebrate (an animal without a backbone). Most shells that are found on beaches are the shells of marine mollusks ("molluscs" in British English), partly because they endure better than other seashells.
Apart from mollusk shells, shells are found on barnacles, horseshoe crabs and brachiopods. Marine annelid worms in the family Serpulidae create shells made of calcareous tubes cemented onto other surfaces. The shells of sea urchins are called tests, and the moulted shells of crabs and lobsters are called exuviae. While most seashells are external, some cephalopods have internal shells.
Seashells have been admired, studied and used by humans for many different purposes throughout history and pre-history. But seashells are not the only kind of shells. In a variety of habitats it is possible to find shells from freshwater animals such as freshwater mussels and freshwater snails, and it is also possible to find shells from land snails.