What is "leptonetidae"

Leptonetidae is a family of relatively primitive haplogyne (lacking hardened external female genitalia) spiders, which includes 15 genera and nearly 200 species. The family is poorly known to anybody but specialists. Leptonetids are generally tiny, have six eyes arranged in a semicircle of four in front and two behind. Many live in caves or in leaf litter. They are found around the Mediterranean, and in Eurasia, Japan and the New World.