The "Stock Island tree snail," Orthalicus reses reses (Say) has been confused with the foreign snail Achatina fulica (Bowdich). However, it can be differentiated from A. fulica because it has a greyish cast (never reddish) to the stripes, underlying spiral bands, and a columella continuous with the aperture, not truncate. O.r. reses is endemic to Stock Island, Monroe County, where it is found on a variety of native and exotic trees.