These are also from Mike's lost gift fossil collection, no location determined as of yet. Your ID will help me do that. I have many more of these. Seem to be all the same genera and species. They have the general form of periwinkles, but they are strangely spirally-beaded. (I understand there are beaded periwinkles), but I thought periwinkles were much smaller, like the specimen in the front, middle.