The black and white illustrations of shells are reproduced by kind permission of the publisher, Harley Books (B.H. & A. Harley Ltd.), from "Atlas of Land and Freshwater Molluscs of Britain and Ireland" by Dr. Michael Kerney, published in 1999.
Is the mouth lip thickened and reflected?
Shell edentulous with an unthickened and unreflected apertural lip.(Columella sp.) Click on the image to the left to continue.
Shell edentulous or with teeth; apertural lip thickened and often reflected. Click on the image to the right to continue.