Dear Erich, The Drupa ricnus with the yellow markings that you have are Drupa ricinus var. arachnoides Lamarck, 1816. I have a number of these in my collection. Most typical ricinus have traces of yellow around the aperture, but arachnoides has a very distinctive ring of yellow-orange dashes around the aperture. Kind Regards, James Ohio Molluscan Studies c/o James M. Cheshire 427 E. College St. Granville, Ohio 43023 USA