Helicidae is a large, diverse family of western Palaearctic, medium to large-sized, air-breathing land snails, sometimes called the "typical snails." It includes some of the largest European land snails, several species are common in anthropogenic habitats, and some became invasive on other continents. A number of species in this family are valued as food items, including Cornu aspersum the brown or garden snail, and Helix pomatia. The biologies of these two species in particular have been thoroughly studied and documented.
Helicidae
Helicid snails for sale as food in Italy; from the front Eobania vermiculata, Cantareus apertus, and Helix sp.
Arianta arbustorum
Iberus gualtieranus alonensis
A land snail is any of the numerous species of snail that live on land, as opposed to the sea snails and freshwater snails. Land snail is the common name for terrestrial gastropod mollusks that have shells. However, it is not always easy to say which species are terrestrial, because some are more or less amphibious between land and fresh water, and others are relatively amphibious between land and salt water.
Helix pomatia, a species of air-breathing land snail used for escargot, is a little bit larger than the common garden snail.
Cornu aspersum (previously Helix aspersa) – the common garden snail – in Israel
Colonies of snails in Sicily
"The Teeth of a Snail" from Robert Hooke's Micrographia, 1665. This actually shows the jaw, against which the teeth on the radula act.