The families of British spiders
Morphology. The adult spiders 4–15 mm long; of medium build; decidedly short-legged; with eight eyes. The eyes comprising four small ones at the extremities constituting a large quadrilateral, with the other four in a small, anterior-median, trapezoid arrangement whose anterior side is shorter and the inner pair of which are the largest of all. Metatarsus IV of the females with a dorsal series of curved bristles (the calamistrum, which is reduced in the males). Tarsal claws 3. The abdomen conspicuously patterned dorsally (the male), or plain dorsally (the female); predominantly bright red, with black markings (in the male), or without any red coloration (the female being almost uniformly velvety black). The abdomen of the females furnished with a plate-like cribellum anterior to the spinnerets (this being reduced in the males).
The adults constructing a terrestrial retreat in the form of a silk tube (this mostly buried, up to 8 cm deep); making snare-webs; constructing tangled webs to constructing horizontal sheet webs (the uppermost, exposed part of the silken tube is extended on one side into a roof-like structure, from which threads extending into the surounding vegetation constitute a small sheet web for snaring ground-running invertebrates).
British representation. 1 species in Britain; in the genus Eresus (E. sandaliatus). Confined to southern England (and known from only one locality).
Illustrations. • Eresus sandaliatus.
To view the illustrations with detailed captions, go to the interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. The families of British spiders. Version: 4th January 2012. http://delta-intkey.com’.