These data supplement the following article: Hutchinson, J.M.C., Schlitt, B. & Reise, H. (in press) Ambigolimax, Lehmannia, and other limacid slugs (Gastropoda: Stylommatophora); what their DNA tells us about phylogeny, taxonomy, and phylogeography. Journal of Molluscan Studies. https://doi.org/10.1093/mollus/eyaf031 Table S1 = list of sequenced taxa with their taxonomic authorities. Table S2 = list of 40 specimens contributing to the four-marker tree (Fig. 1) together with the GenBank numbers for each marker. Table S3 = list of the 219 distinct COI haplotypes, matching the numbers used here as names against GenBank numbers. Table S4 = collection details of specimens sequenced for this study, including the COI haplotype number(s) consistent with the sequence and/or any GenBank entries for other markers. CORRECTION NECESSARY: date of collection of A. wiktori was 27 Feb. 2006, not as given in this table. Table S5 = for each species a list of the GenBank entries from other studies that were included in our analyses.