The pallial line is a mark (a line) on the interior of each

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shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses Science Biology * Seashell, a hard outer layer of a marine ani ...

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bivalve Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed b ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

. This line shows where all of the mantle muscles were attached in life. In clams with two adductor muscles the pallial line usually joins the marks known as adductor muscle scars, which are where the adductor muscles attach. The position of the pallial line is often quite clearly visible as a shiny line on the slightly more dull interior surface of the bivalve shell.Huber, Markus (2010). Compendium of Bivalves. A Full-color Guide to 3'300 of the World's Marine Bivalves. A Status on Bivalvia after 250 Years of Research. Hackenheim: ConchBooks. pp. 901 pp. + CD. , at p. 57

References

Mollusc anatomy {{bivalve-stub