The Spider Genus Theridula In North And Central America And The West Indies

Author : Raymond R. Forster
Publisher :
ISBN 13 :
Total Pages : 120 pages
Book Rating : 4.3/5 ( download)

DOWNLOAD NOW!

Download or read book A Proposal and Review of the Spider Family Synotaxidae (Araneae, Araneoidea) written by Raymond R. Forster and published by . This book was released on 1990 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The previously monotypic subfamily Physogleninae Petrunkevitch is redefined to include Physoglenes Simon--containing P. vivesi Simon and three new species from Chile--and three new genera: Meringa, containing nine new species from New Zealand; Tupua, containing four new species from Tasmania; and Paratupua, containing one new species from Victoria. The physoglenine genera are united by unique modifications of the male pedicel and anterior abdominal region. The new subfamily Pahorinae is established for five new genera from New Zealand: Pahora (containing nine new species), Pahoroides (containing two new species), Wairua (containing two new species), Nomaua (containing five new species and N. crinifrons (Urquhart), transferred from the linyphiid genus Bolyphantes), and Runga (containing five new species). The pahorine genera are united by a carapace-abdomen stridulatory system, secretory pores on the male pars cephalica, and a deeply excavated paracymbial area on the male palp. Three other genera seem closely related to physoglenines and pahorines: Mangua, new genus, containing 13 new species and M. forsteri (Brignoli), transferred from Linyphia, all from New Zealand; Chileotaxus, new genus, containing one new species from Chile; and the Neotropical genus Synotaxus Simon. These spiders have been widely separated in some past classifications; Physoglenes has been variously considered a leptonetid, pholcid, theridiid, or araneoid incertae sedis, whereas the other previously described taxa have generally been considered theridiids or linyphiids. All 12 genera are united by the presence of a small, basally situated and dorsally excavated paracymbium, a longitudinal incision of the retrolateral cymbial margin, thickened (and sometimes spiniform) dorsal macrosetae on the male palpal femur, patella, and/or tibia, and greatly elongated, spineless legs, with the first pair much the longest and all femora basally thickened. The known web forms are diverse, including an irregular sheet (Mangua and at least some physoglenines), an inverted bowl (pahorines), and a latticelike structure (Synotaxus). The absence of a comb on tarsi IV and widened aggregate spigots on the posterior lateral spinnerets, and the presence of a basal paracymbium, indicate that these genera do not belong to the Theridiidae, and the male palpi lack the distinct embolic division including a radix typical of the Linyphiidae. The oldest family-group name available for the assemblage is Synotaxidae, based on Synotaxeae Simon. Synotaxidae is hypothesized to be the sister group of Nesticidae plus Theridiidae. Wunderlich's synonymy of the families Hadrotarsidae and Theridiidae appears to be justified by paracymbial morphology; two possibly monophyletic groups can be recognized among the genera that are currently considered valid members of those families. The genera Anatea Berland, Audifia Keyserling, Dipoena Thorell, Dipoenata Wunderlich, Euryopis Menge, Gmogola Keyserling, Guaraniella Baert, Hadrotarsus Thorell, Lasaeola Simon, and Yoroa Baert are apparently united by a suite of characters (a dorsoventrally flattened female palpal claw, shortened chelicerae with elongated fangs, specialized ventral setae on tarsus I, a series of parallel ridges on the medial surface of the anterior lateral spinnerets, and four rather than two spermathecae) and may all be specialized predators of ants; the earliest available name for the assemblage is Hadrotarsinae Thorell. At least the genera Anelosimus Simon, Chrosiothes Simon, Chrysso O.P.-Cambridge, Coleosoma O.P.-Cambridge, Helvibis Keyserling, Nesticodes Archer, Rugathodes Archer, Spintharus Hentz, Tekellina Levi, Theridula Emerton, Thwaitesia O.P.-Cambridge, and Thymoites Keyserling are apparently united by a distinctive paracymbial hood. The name Spintharinae Simon is available for this assemblage; if Spintharinae is monophyletic, the genera Achaearanea Strand and Anelosimus, as currently construed, may be polyphyletic assemblages that require relimitation"--Page 3