Like mygalomorphs, most hypochilids have two pairs of book lungs, but like araneomorphs they have intersecting fangs, with the exception of some species which have chelicerae in an angle that is neither orthognathous or labidognathous.

[1] These long-legged spiders build typical "lampshade" style webs under overhangs and in caves.

In the United States the fauna is primarily associated with the Appalachian, Rocky and California Mountains.

Ten of the known species are found in these ranges, all in the genus Hypochilus.

In one analysis, the Hypochilidae are a sister clade to the Neocribellatae, which contains all other spider species in the Araneomorphae (Coddington & Levi, 1991, p. 576).