The Philodromid crab spiders are the family Philodromidae, once considered to belong to a subfamily within the crab spiders, family Thomisidae.

However, studies have shown that these two spider groups, though similar, are not as closely related as previously thought. Unlike thomisids, philodromids tend to have few true setae (hairs or spines) on their bodies. They also lack the congruent eye tubercles of some thomisids. The second legs are usually the longer of the four pairs of walking legs and in the genus Ebo this is quite extreme, with the second pair of legs in some species twice as long as the first pair.

The most common genus is Philodromus which, like Ebo is widespread. Other common genera include the elongate grass-dwelling Tibellus and the widespread Thanatus, which includes the widely distributed Holarctic house crab spider Thanatus vulgaris. This species commonly captures flies on and in buildings.

[[Image:Philodromus%2520placcidus-3.gif]]

The spider shown above is a specimen of Pholodromus placcidus, a rather small spider whose behavior is much like that of a jumping spider. It remained calm while exploring the photographer's hand, and seemed somewhat inclined to take occasional short-cuts by jumping. It took shelter for the night in a protected nook in a spare part made of plastic that was lying on the photography stage.

The family contains over 500 species in nearly 30 genera. Most are dull colored- brown, gray, yellowish or mottled, and seldom reach above 10 mm in body length. Most have a leaf-like cardiac mark on the anterior dorsal abdomen. None of the species build webs, but they do use silk for draglines and for egg sacs.

External link

• Platnick, N.I. 2003. World Spider Catalog (http://research.amnh.org/entomology/spiders/catalog81-87/index.html)