Wikipedia
Erigoninae are the largest subfamily of sheet weavers (Linyphiidae), which is itself the second largest spider family. In the United States they are known as dwarf spiders, while they are called money spiders in England. The exact taxonomic limits of the subfamily are not yet known.
Erigoninae are the most numerous of the sheet weavers, with more than 20,000 described species.
Many species live in leaf litter and build minute sheet webs.
These spiders probably are more important as members of the beneficial complex of predators in agroecosystems than is generally known. One species, Atypena formosana lives in colonies in wetland habitats, where it builds nets just above the water line in rice fields to hunt planthopper nymphs.
The most well-known genus is Erigone.