Snail

Snail, herbivorous gastropod mollusk with, typically, a spirally coiled shell, found on land, in fresh water, or in the sea. The shell is secreted by the underlying mantle and houses the internal organs. The internal structure is similar in all groups, though land snails (pulmonates) have air-breathing lungs instead of gills. Nonpulmonate snails are mostly unisexual, while pulmonates are typically hermaphrodite.