
Deroceras reticulatum, Heesch, Netherlands
Bycatch in the tray I used to collect some insects from the garden. Species ID is somewhat of an educated guess. This is a small species, very variable in color, and generally has dark marks as seen here. It's the closest match I could find from species commonly found in gardens. Reference:
https://www.nederlandsesoorten.nl/linnaeus_ng/app/views/species/nsr_taxon.php?id=137654&cat=CTAB_MEDIA#gallery-3
"Deroceras reticulatum", common names "grey field slug" and "grey garden slug", is a species of small air-breathing land slug, a terrestrial pulmonate gastropod mollusk in the family Agriolimacidae. It is important as an agricultural pest.