snail

Common name for members of the class Gastropoda (phylum Mollusca). The freshwater pulmonate (nonoperculated, air-breathing) snails (subclass Pulmonata, order Basommatophora) include the majority of intermediate hosts of trematodes parasitic in humans and domestic birds and mammals, chiefly in the families Lymnaeidae and Planorbidae. The subclass Prosobranchiata, the operculate snails, includes the order Neogastropoda, which includes the venomous stinging cone snails (genus Conus), and the order Mesogastropoda, of which the family Hydrobiidae includes most of the medically important host snails. [M.E. snaile]

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snail 'snā(ə)l n any of various gastropod mollusks and esp. those having an external enclosing spiral shell including some which are important in medicine as intermediate hosts of trematodes

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(snāl) any of numerous gastropods that have external spiral shells; they are divided between the subclasses Euthyneura and Streptoneura. Many snails in tropical countries are intermediate hosts of parasitic trematodes; the miracidium of the parasite develops into a cercaria in the body of the snail. Cf. slug.