Last month, Mike Oldham, Fred Schueler, and I published our paper on Patera appressa in Ontario. This species had been on our radar for some time. Fred discovered it for the first time in Ontario (and Canada) in the spring of 1994. Since that time, all of us have gone back to sites; I was there last September (2014).
This is one of two species of Triodopsis (family Polygyridae) in Canada. Triodopsis vulgata is restricted in Canada to Southwestern Ontario, where it is known from Pelee, Middle and Middle Sister islands, Essex County, and on the mainland in south and west of Wellington County. This somewhat worn shell was retrieved from stream drift but in Canada the species is known from often dry, open or sandy woods with Hackberry or Sugar Maple.