Hendersonia occulta (Say, 1831), the Cherrystone Drop Snail (Gastropoda: Helicinidae), extended geographic distribution, Wisconsin, USA

Abstract

This paper describes a range extension of Hendersonia occulta, the cherrystone drop snail. This species, occurring in heavily wooded areas with carbonate geology, is imperiled in Wisconsin. Prior to our research, H. occulta had been found in 13 counties within Wisconsin, mostly in the southwestern and eastern parts of the state. We have found 13 new populations, both within counties where the snail was known to occur, and within three new counties, representing a ~150 km range extension northward.