parent_taxon anadenidae
Slug , or land slug , is a common name for any apparently shell - less terrestrial gastropod mollusc . The word " slug " is also often used as part of the common name of any gastropod mollusc that has no shell , a very reduced shell , or only a small internal shell , particularly sea slugs and semislugs ( this is in contrast to the common name " snail ", which applies to gastropods that have a coiled shell large enough that the ___MASK1___ can fully retract its soft parts into the shell ). ___MASK50___ is a taxonomic group , superfamily of air - breathing land slugs , shell - less terrestrial pulmonate gastropod mollusks . ___MASK30___ , common name the " roundback slugs " or " round back slugs " are a taxonomic family of air - breathing land slugs , terrestrial pulmonate gastropod mollusks in the superfamily ___MASK50___ . Anadenidae is a taxonomic family of air - breathing land slugs , terrestrial pulmonate gastropod mollusks in the superfamily ___MASK30___ ( according to the taxonomy of the Gastropoda by Bouchet & Rocroi , 2005 ) . This family has no subfamilies ( according to the taxonomy of the Gastropoda by Bouchet & Rocroi , 2005 ) .