Xolotrema - Wedge Snails (Family Polygyridae)
Three species of Xolotrema are possible: the Bladetooth Wedge Snail (Xolotrema fosteri), the Velvet Wedge Snail (Xolotrema denotatum), and the Sharp Wedge Snail (Xolotrema obstrictum). Dourson (2010) has a very good treatment of Xolotrema.
This key is based on Dourson (2010) on characters for KY specimens.
1a. palatal tooth significant and deeply recessed, shell surface with hairs – Xolotrema dentifera