Stylommatophora
Stylommatophora is an order of air-breathing land snails and slugs, terrestrial pulmonate gastropod molluscs. This taxon includes most land snails and slugs. The two strong synapomorphies of Stylommatophora are a long pedal gland placed beneath a membrane and two pairs of retractile tentacles (Dayrat & Tillier). Several families in this group contain species of snails and slugs that create love darts. Stylommatophora are known from the Cretaceous period up to the present day. 2005 taxonomy. According to the taxonomy of the Gastropoda by Bouchet & Rocroi (2005) based on evolutionary ancestry is the clade Stylommatophora in clade Eupulmonata within informal  group Pulmonata. It uses unranked clades for taxa above the rank of superfamily (replacing the ranks suborder, order, superorder and subclass) and the traditional Linnaean approach for all taxa below the rank of superfamily. The clade Stylommatophora contains the subclades Elasmognatha, Orthurethra and the informal group Sigmurethra. 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. clade Elasmognatha clade Orthurethra informal group Sigmurethra "limacoid clade" (within the Sigmurethra)