(Encyclopedia) mollusk: see Mollusca. (Encyclopedia) shell mound, in archaeology, a mound consisting largely of the shells of edible mollusks. It is a kind of kitchen midden found in various parts of the world. (Encyclopedia) shellfish, popular name for certain edible mollusks (see Mollusca), e.g., oysters, clams, and scallops, and for certain edible crustaceans, e.g., crabs, lobsters, and shrimps. All are? (Encyclopedia) Mollusca m?l?sk?, taxonomic name for the one of the largest phyla of invertebrate animals (Arthropoda is the largest) comprising more than 50,000 living mollusk species and about 35,? (Encyclopedia) shell, in zoology, hard outer covering secreted by an animal for protection. It is also called the test, crust, or carapace. The term usually refers to the calcareous shells of the? (Encyclopedia) scallop or pecten, marine bivalve mollusk. Like its close relative the oyster, the scallop has no siphons, the mantle being completely open, but it differs from other mollusks in that? (Encyclopedia) mother-of-pearl or nacren?k?r, the iridescent substance that forms the lining of the shells of some fresh-water and some salt-water mollusks. Like the pearl it is a secretion of the? (Encyclopedia) ammonite ?m?n?t, one of a type of extinct marine cephalopod mollusk, related to the nautilus and resembling it in having an elaborately coiled and chambered shell. Unlike the? (Encyclopedia) periwinkle, any of a group of marine gastropod mollusks having conical, spiral shells. Periwinkles feed on algae and seaweed. They are found at the water's edge; out of water,? (Encyclopedia) Milne-Edwards, Henri Nr? m?l?n?dwrs, 1800?1885, French naturalist. He became professor at the Sorbonne (1843) and served at the Museum of Natural History, Paris, as professor (from?