Bioacoustics of Agyneta amersaxatilis

Female : Total length 2.24; carapace length 0.88, width 0.62. CEPHALOTHORAX: Carapace yellow-orange, shiny, finely reticulate. Clypeus height 2. Chelicerae promargin six teeth, retromargin five teeth. Cheliceral stridulatory organ ~ 30 striae, well spaced, slowly getting closer basally. ABDOMEN: Uniformly light gray. LEGS: Yellow; palpal tarsal claw absent; leg I total length: 2.99; leg III total length: 2.40; Tm I: 0.26, Tm IV: absent. GENITALIA: Epigynum with wide, concave proximal part of scape with oblique sides; epigynal slits oval; pit hook depression deep ( Fig. 471 ); lateral lobes elongated, folded; stretcher small; pit deep ( Fig. 472 ). Median part of scape short; genital pores situated at base of lateral lobes pockets ( Fig. 473 ). Internal genitalia with elongated ventral and dorsal receptacula, obliquely positioned ( Figs 472, 473 ).

Diagnosis: Males are easily diagnosed from all Agyneta by their rounded, rugose dorsal palpal tibial apophysis ( Fig. 466 ). Females are differentiated from all species by their sunken proximal part of scape ( Fig. 471 ). Description: Male : Total length 2.25; carapace length 1.01, width 0.74. MAP. 31. Localities of Agyneta amersaxatilis Saaristo & Koponen 1998 . CEPHALOTHORAX: Carapace dark orange-brown, shiny, finely reticulate; margin, radiating lines suffused with dark gray; trident mark present. Clypeus height 2. Sternum strongly suffused with dark gray. Chelicerae dark orange, excavated; ~ 12 seta-tipped tubercles; promargin three teeth, retromargin two tiny denticles; both margins with triangular projection at base of fang. Cheliceral stridulatory organ ~ 19 striae, very well spaced the last seven striae close together. ABDOMEN: Uniformly dark gray LEGS: Dark orange; leg I total length: 3.04; leg III total length: 2.17; Tm I: 0.26, Tm IV: absent. GENITALIA: Palpal retrolateral tibial apophysis pointed, rugose; dorsal tibial apophysis rounded, rugose; two retrolateral and one dorsal trichobothria ( Fig. 466 ). Cymbium triangular; glabrous depression present ( Fig. 466 ); cymbial turbercles absent; prolateral notch shallow ( Fig. 467 ). Paracymbium apical pocket short, anterior pocket absent, posterior pocket spine-like ( Fig. 466 ). Embolus tip pointed; basally with one sharp spike and a row of small ones; ventrally with small spines; Fickert’s gland absent; ventral lamella short, serrated apically; thumb exceptionally short ( Fig. 468 ). Embolus proper set medially, anterior part shorter, serrated ( Fig. 468 ). Anterior terminal apophysis pointed, basally well-sclerotized, with numerous short and long protrusions; posterior terminal apophysis bifid, one part smooth, one part striated; lamella characteristica short with well sclerotized dentate tip ( Fig. 469 ). GENITALIA VARIATION: Two males from NWT, Involuted Hills, show variation. The retrolateral palpal tibial apophysis is absent, the dorsal tibial apophysis is longer. Futhermore, the lamella characteristica is less sclerotized with reduced prongs ( Fig. 470 ) and the base of the embolus lacks the row of spines.