A new species and new records of linyphiid spiders ( Araneae : Linyphiidae ) from Amazonas , Brazil

Linyphiidae is currently the second richest family of spiders in the order Araneae but is poorly known and studied in Brazil, particularly in the northern states. In this contribution we describe a new species of Exechopsis Millidge, 1991 from the State of Amazonas, based on both males and females. The male of Meioneta adami Millidge, 1991 is described for the first time. Mermessus conjunctus (Millidge, 1991), Novafrontina uncata (F. O. Pickard-Cambridge, 1902), Sphecozone fastibilis (Keyserling, 1886), Sphecozone ignigena (Keyserling, 1886) and Vesicapalpus simplex Millidge, 1991 are recorded for the first time from Amazonas. Sphecozone crassa (Millidge, 1991) are presented additional record from

The Linyphiidae consists mainly of very small spiders, which are sheetweb builders (ROBERTS 1987, DRANEY & BUCKLE 2005, MILLER 2007).The presence of a discrete, intersegmental paracymbium (rarely missing); stridulatory striae file on the ectal side of the chelicerae; and autospasy of the legs at the patella-tibia junction distinguish this family from all others, except Pimoidae (DRANEY & BUCKLE 2005).Linyphiids distinguished from Pimoidae by lacking a retrolateral cymbial sclerites attached to the cymbium via a membrane (DRANEY & BUCKLE 2005).Linyphiidae, with 4,412 extant species in 587 genera (PLATNICK 2012) is the second richest family of spiders in the order Araneae in terms of number of species.Despite of this, taxonomic studies on Neotropical Linyphiidae are rare.
Most species of Linyphiidae were described from South America by MILLIDGE (1991), and only two species are known to occur in the state of Amazonas, in the northern portion of Brazil -Meioneta adami Millidge, 1991 andTutaibo niger (O. Pickard-Cambridge, 1882).
The examination of specimens from State of Amazonas, in Brazilian collections, allowed the recognition and description of a new species of Exechopsis Millidge, 1991, based both males and females, as well as the description of the male of Meioneta adami Millidge, 1991 for the first time.The following species are recorded for the first time from Amazonas: Mermessus conjunctus (Millidge, 1991), Novafrontina uncata (F.O.Pickard-Cambridge, 1902), Sphecozone fastibilis (Keyserling, 1886), Sphecozone ignigena (Keyserling, 1886) and Vesicapalpus simplex Millidge, 1991.Additional records of Sphecozone crassa (Millidge, 1991) are presented.

MATERIAL AND METHODS
All specimens examined and studied herein are deposited in the arachnological collections of the Instituto Butantan, São Paulo (IBSP, D.M.B. Battesti, curator); Instituto Nacional de Pesquisas da Amazônia, Manaus (INPA, C. Magalhães) and Museu de Ciências Naturais da Fundação Zoobotânica do Rio Grande do Sul, Porto Alegre (MCN, R. Ott).For illustrations, the specimens were examined under a Leica ® MZ9.5 with camera lucida.The study of the reproductive structures of both males and females was performed by immersing the epigynum and the embolic division in methyl salicylate and/or clove oil for approximately 30 minutes until the internal structures could be perfectly visualized.The palp was immersed in 10% potassium hydroxide for approximately two hours, and after that immersed in distilled water (LEVI 1965).This process expands it and allows for a better visualisation of the parts.The specimens are preserved in 70-80% ethanol.All measurements were made using a scale reticle on the objective of the stereomicroscope, and are expressed in millimeters.The descriptions and terminology follow MILLIDGE (1980) andMILLER (2007), respectively.The tibial spine formula follows ROBERTS (1987).Abbreviations: (AME) anterior median eyes, (ALE) anterior lateral eyes, (PLE) posterior lateral eyes and (PME) posterior median eyes.

A new species and new records of linyphiid spiders (Araneae:
Linyphiidae) from Amazonas, Brazil Diagnosis.The male of Exechopsis eberhardi sp.nov.resembles that of E. versicolor Millidge, 1991(MILLIDGE 1991: 56, figs 184, 185, 188) in the shape of the tegulum and subtegulum; the radix developed (Fig. 2) and large eyes with AME protuberant (Fig. 5).It differs from it in the radix mesally rounded near the margin of cymbium (Fig. 2), tegulum wider distally and lamella characteristica with blunt end (Figs 1 and 2).The female of E. eberhardi sp.nov. is characterized by epigynum with a relatively large atrium, without median septum; ventral plate wider than long and dorsal plate developed, wider in the posterior region (Fig. 7).