Obese Thorn Snail (Carychium exiguum) is a tiny (shell height 1.2-2.5 mm) terrestrial snail that is distributed from New Mexico and Texas of the United States north and eastward to the maritime provinces of Canada. In New Mexico they occur along the Tularosa River at the U.S. National Fish Hatchery and near the village of Mescalero in Otero County. There they inhabit damp, marshy habitats at elevations of 2,025-2,070 m.