https://www.usgs.gov/publications/north-american-paleozoic-land-snails-a-summary-other-paleozoic-nonmarine-snails
North American Paleozoic land snails, with a summary of other Paleozoic nonmarine snails | U.S....
Land snails from the Paleozoic of North America are known from the coal fields of eastern Canada, from the Dunkard basin west of the Allegheny Mountains, and...