Agyneta sheffordiana Dupérré & Paquin 2007

Dupérré, Nadine, 2013, Taxonomic revision of the spider genera Agyneta and Tennesseellum (Araneae, Linyphiidae) of North America north of Mexico with a study of the embolic division within Micronetinae sensu Saaristo & Tanasevitch 1996, Zootaxa 3674 (1), pp. 1-189 : 154-156

Agyneta sheffordiana Dupérré & Paquin 2007

Figs 503–510

Agyneta sheffordiana Dupérré & Paquin 2007: 3 , f. 1–9. (Description Ƥ).

Type material: Agyneta sheffordiana Dupérré & Paquin 2007 , 3 HOLOTYPE from Québec: Parc National de la Yamaska, 45.42°N, 72.39°W, 18–25.vii.2006, pitfall, deciduous forest in regeneration, A. Mochon ( AMNH). EXAMINED.

Diagnosis: Males are distinguished from most species in the genus by their elongated and narrow lamella characteristica, apically serrated ( Fig. 503 ) comparable to A. mollis . They can be differentiated from the latter by the absence of a retrolateral tibial apophysis ( Fig. 503 ). Females are diagnosed from all other species by their short, rectangular proximal part of scape ( Fig. 508 ).

Description: Male: Total length 1.35; carapace length 0.60, width 0.41.

CEPHALOTHORAX: Carapace light khaki-brown, shiny, finely reticulate; suffused with dark gray along margin, radiating lines; trident mark present. Sternum suffused with dark gray. Clypeus height 2. Chelicerae light khaki-brown with transverse gray band, not excavated; seta-tipped tubercles absent; promargin four teeth, retromargin four denticles. Cheliceral stridulatory organ ~16 strong striae, well spaced. ABDOMEN: Uniformly light gray. LEGS: Light yellow, prolateral and retrolateral surface of palpal femora and leg femora I–III suffused with dark gray; leg I total length: 2.38, leg III total length: 2.16, Tm I: 0.24, Tm IV: absent. GENITALIA: Palpal retrolateral tibial apophysis absent; dorsal tibial apophysis pointed, rugose; one retrolateral trichobothria and one dorsal ( Fig. 503 ). Cymbium triangular; glabrous depression present with keel ( Fig. 503 ); dorsal cymbial tubercle absent; ventral tubercle triangular, rugose; prolateral notch shallow ( Fig. 504 ). Paracymbium apical pocket short, anterior pocket absent, posterior pocket short ( Fig. 503 ). Embolus tip rounded; basally with three small spines; Fickert’s gland situated medially, globulous; ventral lamella transparent, pointed; thumb long going over the embolus proper ( Fig. 505 ). Embolus proper set apically, of equal part ( Fig. 505 ). Anterior terminal apophysis narrow, tip with few protrusions; posterior terminal apophysis reduced, not well sclerotized; lamella characteristica long, with a basal triangular process, a medially dentate process ( Fig. 506 ) and serrated tip (variable) ( Fig. 507 ).

Female: Total length 1.64; carapace length 0.62, width 0.42.

CEPHALOTHORAX: Same coloration as male. Chelicerae promargin four teeth, retromargin three denticles. Cheliceral stridulatory organ ~15 striae, well spaced. ABDOMEN: Same coloration as male. LEGS: Same coloration as male; palpal claw absent; total length leg I: 2.45, total length leg III: 2.22, Tm I: 0.22, Tm IV: absent. GENITALIA: Epigynum with proximal part of scape wide, sides parallel; epigynal slits small; pit hook depression very shallow ( Fig. 508 ); lateral lobes large; stretcher small; pit deep ( Fig. 509 ). Median part of scape narrow; genital pores situated at base of lateral lobes pockets ( Fig. 510 ). Internal genitalia with one large, rounded receptacula and a small triangular one ( Figs 509, 510 ).

Other material examined: For detailed localities (see Dupérré & Paquin 2007: 3).

Distribution: Northeastern Canada (see Dupérré & Paquin 2007, p.9, fig. 19).

The majority of the following species share one characteristic not found in the other species of Agyneta , the absence of the cymbial glabrous depression. Even so, differences in the embolus and the radical division morphology suggests that they are not closely related to each other.

Figures

FIGURES 503 – 510. Agyneta sheffordiana Dupérré & Paquin 2007. 503 – 507, Male. 508 – 510, Female. 503. Palp, retrolateral view. 504. Palp, prolateral view. 505. Embolus, prolateral view. 506. Radical division, retrolateral view. 507. Variation of tip of lamella characteristica, retrolateral view. 508. Epigynum, ventral view. 509. Internal genitalia, ventral view. 510. Internal genitalia, dorsal view.