Stylommatophora is an order[3] of air-breathing land snails and slugs, terrestrial pulmonate gastropod molluscs.

The two strong synapomorphies of Stylommatophora are a long pedal gland placed beneath a membrane and two pairs of retractile tentacles.

[3] Parts of the 2017 system have become obsolete due to new phylogenetic studies and continuously updated information may be found at MolluscaBase.

[7] Rhytidoidea is apparently not a monophyletic group, but rather a collection of lineages from the southern hemisphere with unresolved relationships.

The term "informal group" has been used to indicate whenever monophyly has not been tested, or where a traditional taxon of gastropods has now been discovered to be paraphyletic or polyphyletic.