page_title: Valve (mollusc)
section_title: Chitons
hierarchical_section_title: Valve (mollusc) / Chitons
caption_attribution_description: Tonicella lineata
context_page_description: A mollusc valve is each articulating part of the shell of a mollusc. Each part is known as a valve or in the case of chitons, a "plate". Members of two classes of molluscs: the Bivalvia and the Polyplacophora have valves.
  Species within one family of very unusual small sea snails, marine opisthobranch gastropods in the family Juliidae, also have two articulating shells or valves, which resemble those of a bivalve. This exceptional family is commonly known as the bivalved gastropods. Gastropods in general are sometimes called "univalves", because in those that have a shell, the shell is usually in one part.
context_section_description: The valves of chitons are eight dorsal, articulated shell plates, which are frequently coloured and sculpted. After death the girdle that holds the plates together disintegrates and the plates separate. Thus individual plates can be found washed up in beach drift, as shown in the image at the top of this article.
caption: Live individual of the lined chiton Tonicella lineata, head end towards the right
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