Bioacoustics of Stenosfemuraia

Description. Male. Total body length 2.5–3.5; carapace width 1.0–1.4. Carapace posteriorly elevated ( Figs 3 , 16 , 29 ), with deep median furrow; ocular area weakly raised, eight eyes relatively close together, AME very small. Clypeus high, unmodified. Chelicerae never with stridulatory ridges, with one or two pairs of frontal apophyses ( Figs 11 , 24 , 37 ), without modified hairs. Palpal coxa with retrolatero-ventral apophysis; trochanter barely modified; femur with retrolatero-ventral process proximally and ventral apophysis distally; procursus simple ( Figs 43–44, 47–48, 51–52 ); bulb with slender distal apophysis and two dorsal processes ( Figs 41–42, 45–46, 49–50 ). Legs relatively short, leg 1 length 13–24, tibia 1 length 3.1–5.7, tibia 2/tibia 4 length 0.9–1.1. Tibia 1 L/d ~25– 60. Femora sometimes thickened ( S. parva , S. pilosa ). Legs without spines, with curved hairs on tibiae and metatarsi, retrolateral trichobothrium at 6–9%, prolateral trichobothrium always present (also on tibiae 1). Tarsal pseudosegments distinct. Abdomen round to oval, higher than long, with dark internal marks dorsally and laterally ( Figs 2–3 , 15–16 , 28–29 ). Female. Very similar to male ( Figs 4–5 , 17–18 , 30–31 ), carapace less elevated, legs usually without curved hairs, legs shorter than in male, leg femora never thickened. Epigynum with large protruding weakly sclerotized area in front of epigynal plate ( Figs 6–7 , 19–20 , 32–33 ), the latter weakly curved, without processes or pockets; simple posterior plate. Internal female genitalia with anteriorly diverging sclerites/‘wings’, membranous median sac, and pair of pore plates ( Figs 14 , 27 , 40 ). Relationships. Previous molecular phylogenies have suggested a close relationship of Stenosfemuraia with the Venezuelan (or mostly Venezuelan) genera Mecolaesthus , Coryssocnemis , and Systenita ( Bruvo-Mađarić et al. 2005 ; Astrin et al. 2007 ). This is also supported in our most recent molecular phylogeny of the family (J. Eberle et al. , unpublished data). Relationships among and within these genera remain poorly resolved. Even the monophylies of the genera need further study, i.e. some genera may actually be nested within a paraphyletic Mecolaesthus (as for example Coryssocnemis - but not Stenosfemuraia - in our most recent molecular phylogeny of the family; J. Eberle et al. , unpublished data). Natural history. All newly collected specimens below were found near the ground, mostly in forest litter, but also under larger objects like logs and rocks. Males and females were often found in close proximity. When disturbed, the spiders vibrated rapidly.