These spiders remind of the Gnaphosidae, but in contrast to that family they have closely spaced spinnerets. They are nocturnal hunting spiders that hide in a retreat during the day. Often this retreat is a rolled-up / folded leaf that is fastened and lined with silk. It is sac-shaped, hence the English common name for the family: Sac Spiders. In Europe about 50 species occur within a single genus.
With the exception of a single species, these spiders have little to no markings on the abdomen and they are all grey-brown to a reddish brown, making it difficult to tell them apart. They are common in damp areas and on low vegetation, sometimes in taller trees and shrubs.