Snail

Snail:  Snail is a common name which is applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often applied to land snails than to those from the sea or freshwater. Snail-like animals that naturally lack a shell, or have only an internal shell, are often called slugs, and land species that have only a very small shell (that they cannot retract into) are called semislugs.

 Some organisms that are not gastropods, such as the monoplacophora, may informally be referred to as snails.Snails that respire using a lung belong to the group Pulmonata, while those with gills form a polyphyletic group; in other words, snails with gills form a number of taxonomic groups that are not necessarily more closely related to each other than they are related to some other groups. Snails with lungs and with gills have diversified so widely over geological time that a few species with gills can be found on land, numerous species with a lung can be found in freshwater, and a few marine species have lungs.

 Snail

 Snail

 Snail

Snail