land snail A land snail is any of the numerous species of snail that live on land, as opposed to sea snails and freshwater snails. Land snail is the common name for terrestrial gastropod mollusks that have shells (those without shells are known as slugs). [https://en.wikipedia.org/wiki/Land_snail] garden snail helix spp. snail, garden snail, land snail terrestrial invertebrate requires discussion