Sheetweb spider (Family: Linyphiidae)
Common name: Sheetweb, Sheet weavers, Dwarf weavers, Money Spiders
Linyphiidae is a family of very small spiders, including more than 4,300 described species in 578 genera worldwide. This makes Linyphiidae the second largest family of spiders after the Salticidae. New species are still being discovered throughout the world, and the family is poorly known. Because of the difficulty in identifying such tiny spiders, there are regular changes in taxonomy as species are combined or divided.
Spiders in this family are commonly known as sheet weavers (from the shape of their webs), or money spiders (in the United Kingdom, Ireland, Australia, New Zealand, and in Portugal, from the superstition that if such a spider is seen running on you, it has come to spin you new clothes, meaning financial good fortune).
There are six subfamilies, of which Linyphiinae (the sheetweb spiders), Erigoninae (the dwarf spiders), and Micronetinae, contain the majority of described species.
Common genera include Neriene, Lepthyphantes, Erigone, Eperigone, Bathyphantes, Troglohyphantes, the monotypic genus Tennesseellum and many others. These are among the most abundant spiders in the temperate regions, although many are also found in the tropics. The generally larger bodied members of the subfamily Linyphiinae are commonly found in classic "bowl and doily" webs or filmy domes. The usually tiny members of the Erigoninae are builders of tiny sheet webs. These tiny spiders (usually 3 mm or less) commonly balloon even as adults and may be very numerous in a given area on one day, only to disappear the next. Some males of the erigonines are exceptional, with their eyes set up on mounds or turrets. This reaches an extreme in some members of the large genus Walckenaeria, where several of the male's eyes are placed on a stalk taller than the carapace.
The distribution: Spiders of this family occur nearly worldwide. In Norway many species have been found walking on snow at temperatures of down to -7 °C. (The above text thanks to Wikipedia)
Photos below are of a Linyphiidae spider (unknown spp.) 6mm long body.