Sac spider
The
sac spiders of the family
Clubionidae have a very confusing taxonomic history. Once this family was a large catch-all taxon for a large group of disparate collection of
spiders, similar only in that they had eight eyes arranged in two rows, conical anterior spinnerets that touched and were wandering predators that built silken retreats, or sacs, usually on plant terminals, between leaves, under bark or under rocks. These are now recognized to include several families, some of which are more closely related to the three-clawed spiders, like lynx and
wolf spiders, than to true "clubionoids."
Among the families formerly classified as sac spiders, some of which have common names including the words "sac spider", include:
as well as the remnant Clubionidae (now consisting of a little over 500 species in 15 genera worldwide). However "sac spider" used on its own should imply a member of the family Clubionidae.
In North America the family as it is now recognised consists of only two genera, Clubiona and Elaver (formerly Clubionoides). Clubiona is nearly worldwide in distribution.
