an invertebrate of a large phylum which includes snails, slugs, mussels, and octopuses. They have a soft unsegmented body and live in aquatic or damp habitats, and most kinds have an external calcareous shell 软体动物
Phylum Mollusca: several classes, in particular Gastropoda, Bivalvia, and Cephalopoda 软体动物门:数纲,尤指腹足纲、双壳纲和头足纲
派生 molluscan [məˈlʌskən] adjective 语源
late 18th cent.: from modern Latin mollusca, neuter plural of Latin molluscus, from mollis 'soft'