Roswell Springsnail (Pyrgulopsis roswellensis) is a tiny (shell length up to 3 mm) thermal spring snail that can only be found at the Roswell Country Club and in three springs in the Bitter Lake National Wildlife Refuge in New Mexico. They live on pebbles and gypsum silt in slow-to-moderate velocity perennial water. As current flow slows, snail density decreases.