Ainohelix editha from Hokkaido, Japan, exhibit great geographical variation in their shell morphology. In particular, A. editha in two quite separate locations, Shimamaki and Samani, are striking because they are extremely flat and have a sharp keel, whereas at adjacent sites the shells are globular or depressed‐globular. We used mitochondrial 16S rRNA and nuclear ITS‐2 sequences to infer a phylogeny among 47 snails from 29 lo...