The Lampshade spiders of the family Hypochilidae are among the most primitive of araneomorphspiders. There are two genera and twelve species currently recognized. Like mygalomorphs, hypochilids have two pairs of book lungs, but like araneomorphs they have intersecting fangs. 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. The genus Ectatosticta is found in China.
Forster, R.R., Platnick, N.I. and Gray, M.R. (1987). A review of the spider superfamilies Hypochiloidea and Austrochiloidea (Araneae, Araneomorphae). Bulletin of the AMNH 185(1):1-116 Abstract - PDF (50Mb)
Shear, W.A. (1969). Observations on the predatory behavior of the spider Hypochilus gertschi Hoffman (Hypochilidae). Psyche 76:407-417 PDF