I felt like looking for snails today during my after lunch walk. Fortunately the 1st spot I chose, a rotting, moss-covered railroad tie in a hedgerow alongside the railroad, had enough of them to satisfy me.
I found 7 empty Triodopsis shells and 1 juvenile Mesodon thyroidus in the soft, damp soil next to the tie.
These snails, especialy the Triodopsis, are quite common in that area. They are associated with the railroad. The crushed limestone used as railroad ballast is undoubtedly a factor in their proliferation. I suspect railroad activities are also somehow involved in their dispersal.
Although I have been collecting this particular Triodopsis for several years, I haven't yet bothered to figure out which of the many species it is.