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Lace-webbed Spiders.
Morphology. The adult spiders 4–15 mm long; of medium build, or decidedly plump-bodied; decidedly short-legged, or with legs of medium length (about as long to about 2.5 times as long as the body); with eight eyes. The eyes in two horizontal rows of 4; all clear and glassy (“light in colour”). The palpal organs of the male of complex structure and enclosed by the specialized, hollowed tarsal segment (the cymbium). Metatarsus IV of the females with a dorsal series of curved bristles (the calamistrum, which is reduced in the males); the bristles in two rows. Tarsal claws 3. The abdomen conspicuously patterned dorsally. The abdomen of the females furnished with a plate-like cribellum anterior to the spinnerets (this being reduced in the males).
The adults making snare-webs; constructing tangled webs (these fuzzy, with a circular retreat, in walls or tree bark).
Representation in Britain and Ireland. 3 species in Britain; in the genus Amaurobius.
Illustrations. • Amaurobius fenestralis, with dissections. 88, Amaurobius fenestralis (Stroem): a, female; b, male; c, eyes; d, maxillae, labium and chelicerae; e, spinnerets; f, palpal organs of the male; g, the hind leg, showing the calamistrum; h, the calamistrum, enlarged. From Blackwall (1861). • Amaurobius fenestralis and A. similis. 88, Amaurobius fenestralis (Stroem): a, female; b, male (see preceding image for details). 89, Amaurobius similis (Bl.): a, female; b, male; c, palpal organs of the male; d, the same in profile. From Blackwall (1861). • Amaurobius ferox. Amaurobius ferox (Walck.): a, female; b, male; c, a dark variety of the female; e, palpal organs of the male; e, upper surface of radial and digital joints; f, the same in profile, from the outer side. From Blackwall (1861). See next image for another form of the female. • Amaurobius ferox. This is Ciniflo mordax Bl., = another form of the female Amaurobius ferox (Walck.). From Blackwall (1861).
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, 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. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. The spider families of Britain and Ireland. Version: 5th August 2019. delta-intkey.com’.
