A new Peruvian species of Enna (Araneae, Lycosoidea, Trechaleidae).

The spider genus Enna O. Pickard-Cambridge, 1897 comprises 38 species, distributed from Mexico to Southern Brazil, and is the most diverse genus of Trechaleidae (Platnick, 2013). Enna was revised by Silva et al. (2008) and 13 further species were described by Silva & Lise (2009a, 2009b), Carico & Silva (2010), Silva & Lise (2011) and Silva et al. (2012). Silva & Lise (2010) and Silva et al. (2012) also synonymised two Enna species. Currently, there are 11 Enna species known from Peru (Silva et al. 2008; Silva & Lise 2009a, 2009b, 2011; Carico & Silva 2010; Silva et al. 2012). In this work, a new species of Enna is described and illustrated from Peru. A distribution map is provided. The material examined is deposited in Museo de Historia Natural de la Universidad Mayor de San Marcos, Lima, Peru (MUSM) and The Field Museum of Natural History, Chicago, USA (FMNH). The nomenclature of the female epigynum structures follows Carico (1993) and Silva et al. (2008). To study the excised epigyna, the soft tissue was removed by a combination of dissection with a small surgical blade and immersion in the enzyme trypsin for 48 hours at 25°C. All the measurements are in millimeters. The photos of the female genitalia were obtained using a Nikon D1X Camera Body adapted to an Infinity K1 Long Distance Microscope with an Infinity Achrovid 5x Objective. Photos of habitus were obtained using a Sony W560 camera attached to a Zeiss SV6 stereomicroscope. Images were edited using Adobe Photoshop CS2 and Adobe Lightroom 4.4. The distributional map was made with the program Croizat version 1.16b (Cavalcanti 2009). Abbreviations related to eye measurements: AE row = width of anterior eye row, PE row = width of posterior eye row, OQA = width of ocular quadrangle anteriorly, equivalent to the outer distance of anterior median eyes, OQP = width of ocular quadrangle posteriorly, equivalent to the outer distance of posterior median eyes, OQH = height of ocular quadrangle, equivalent to the outer distance of anterior median eyes and posterior median eyes, PLE = posterior lateral eye, PME = posterior median eye, ALE = anterior lateral eye, AME = anterior median eye, PLE-PME = distance between posterior lateral eye and posterior median eye, PME-PME = distance between posterior median eyes, ALEAME = distance between anterior lateral eye and anterior median eye, AME-AME = distance between anterior median eyes. Abbreviations related to female genitalia: AS, accessory spermatheca; FD, fertilization duct; HS, head of spermatheca; LL, lateral lobes; MF, middle field of epigynum; SC, scape.