(MD) (Natural History Society of Maryland) The Potomac River is a snail haven, home to almost half of these known species. In this presentation, Aydin Orstan, Ph.D. will report on his recent two-year snail survey, which added three more species to the list: Cipangopaludina cf. japonica, Gillia altilis, and Laevapex fuscus.  Aydin will introduce the snails, including the largest native species, Campeloma decisum, with shells up to 1.3 inches ...