A new species of Psilocymbium with the description of the male and new records of P . lineatum at South Brazil ( Araneae : Linyphiidae )

The Neotropical genus Psilocymbium Millidge, 1991 can be recognized by the presence of a non-flagelliform, rigid and spiral shaped embolus, the absence of a cymbial basal excavation on the palp (males), and by having prolonged spermathecae on the epigynum and strong pedipalp setae (females). In this paper Psilocymbium antonina sp. nov., is described based on male and female specimens from the state of Paraná, southern Brazil. Psilocymbium antonina sp. nov. is diagnosed by the following combination of characters: prominent tibial apophysis with gauged distal projection, acute dorsal cymbial apex and acute cymbial proximal region of the palp (male); fertilization ducts distant from each other and the coiled copulatory ducts of the female epigynum. The male of P. lineatum (Millidge, 1991) is described and recorded for the first time in the states of Paraná and Rio Grande do Sul, Brazil.


MATERIAL AND METHODS
Specimens are deposited at the collection of the Museu de Ciências Naturais, Fundação Zoobotânica do Rio Grande do Sul (MCN, Erica H. Buckup), Porto Alegre, Rio Grande do Sul, Brazil.Specimens were illustrated using a Leica ® MZ9.5 stereoscope with a camera lucida.Trichobothrium position on metatarsus I was calculated following DENIS (1949).The descriptions and the terminology of palpal morphology follow MILLIDGE (1991) and HORMIGA (2000).The tibial spine formula follows ROBERTS (1987).The study of reproductive structures of both male and female was performed by immersing the epigynum and the embolic division in lactic acid and/or clove oil for approximately 30 minutes until the internal structures could be perfectly visualized.For the expansion of structures the palp was immersed in 10% KOH for approximately two hours and after that immersed in filtered water.Measurements are expressed in millimeters.Abbreviations: (AME) anterior median eyes, (ALE) anterior lateral eyes, (PLE) posterior lateral eyes and (PME) posterior median eyes; (TmI) trichobothrium position on metatarsus I.
A new species of Psilocymbium with the description of the male and new records of P. lineatum at South Brazil (Araneae: Linyphiidae)  Diagnosis.The male palp of Psilocymbium antonina sp.nov.resembles that of P. tuberosum Millidge, 1991(MILLIDGE 1991: figs 785-787;MILLER 2007: figs 173a, b) by having an enlarged embolus with hooked tip (Figs 1 and 2), the anterior radical process projected and directed toward the cymbial apex, and a broad suprategulum (Fig. 2); it differs from the palp of P. tuberosum by the prominent tibial apophysis with gauged distal projection, acute dorsal cymbial apex and acute cymbial proximal region (Figs 1 and 2).The epigynum resembles that of P. tuberosum (MILLIDGE 1991: figs 789-790;MILLER 2007: figs 173e, 176c) in having a dorsal plate that is longer than wide (Fig. 3), and differs in the fertilization ducts, more separated from each other, the coiled copulatory ducts and the round spermathecae (Fig. 4).
Distribution.Only known from the type locality in Paraná, Brazil.
Etymology.The species epithet, in apposition, refers to the type locality.
Natural history.Collected with beating tray at bush and tree vegetational strata and in litter with pitfall-traps, all at Atlantic Forest areas.
Natural history.Collected from riparian and restinga forests of southern Brazil with a beating tray underneath bush and tree vegetational strata.
Remark.The description and illustrations MILLER (2007) and MILLIDGE (1991) render the examination of the type material of this species unnecessary.