Aglaoctenus yacytata sp. nov.

(Figs 7–9, 18 b, 19b, 21)

Type material. Female holotype from Argentina: Misiones: Departamento Cainguás, Parque Provincial Salto Encantado, Salto Agutí (ca. S 27.0619444° W 54.8352778° -+ 3479 m), 11.I.2005, Grismado, C., Lopardo, L., Piacentini, L., Quaglino A. and Rubio, G. (MACN-Ar 24106; temporary preparation LNP-00604). Four females paratypes from the same province, Departamento de San Pedro, Parque Provincial Cruce Caballero (26°28’S, 53°58’W GPS), 13–16.I.2005, Grismado, C., Lopardo, L., Piacentini, L., Quaglino, A. and Rubio, G. (MACN-Ar 24105; temporary preparations LNP-00578 and LNP-00579).

Other material examined. ARGENTINA: Misiones: No further locality (ca. S 26.928333° W 54.598056° -+ 203397 m) XI-XII.1957, Cranwell, J. A., 1 female (MACN-Ar 24111); same locality and collector, XI-XII.1957, 1 female (MACN-Ar 24107); same data as holotype [1 juvenile] (MACN-Ar 20394); Departamento Manuel Belgrano, San Antonio (ca. S 26.060538° W 53.737163° -+ 1077 m), I.1966, Galiano, M. E., 1 female (MACN-Ar 24108); Piñalitos (ca. S 25.982358° W 53.897255° -+ 1556 m), 1954, Partdridge, 1 female (MACN-Ar 24109); Yacu-Poí, 30 Km de Puerto Bemberg (ca. S 25.937071° W 54.256221° -+ 3025 m), II.1951, Cranwell, J. A., 1 female (MACN-Ar 3340); same data, 1 female [4 juveniles] (MACN-Ar 3341); same locality, X.1954, Orfila, R., 1 female (MACN-Ar 24110); Yacuí (ca. S 25.671686° W 54.162192° -+ 9516 m), 27.IX.1947, Duret, P. J., 1 female (MACN-Ar 4111).

Diagnosis. This species is distinguished from other Aglaoctenus, except for A. lagotis (Fig. 17) and A. castaneus, by the inverted T-shape of the median septum, without lateral projections (Fig. 8 a). The anterior lateral eyes on small tubercles (Figs 19 b, e) and the colour pattern of the carapace (Figs 7 a, c) distinguish this species from A. lagotis (Figs 16 a, c) and A. castaneus .

Description. Female (holotype). Colour in ethanol (Figs 7, 19 c): carapace, dark reddish-brown, covered by dark setae, with light submarginal bands enhanced by white setae (orange in live specimens (Fig. 9)). Chelicerae, endites and labium, dark brown. Sternum reddish-brown, coxae brown. Venter of femora, patellae and basal third of tibiae, light brown, dorsally brown with darker areas; distal tibiae, metatarsi and tarsi brown. Scopulae dense from the tibiae through tarsi. Abdomen dorsally brown without clear pattern, ventrally light brown.

Epigyne (Fig. 8 a), median septum with inverted T-shape, without lateral projections, covered by plumose setae. Internal genitalia (Figs 8 b, 18b), spermatheca with a long and medially curved stalk, vulval chamber semioval. Head of spermatheca branched and with small projections. Fertilization duct small and membranous, connected to the base of spermatheca posteriorly.

TL 18.09, CL 9.40, CW 7.45, CH 2.79. Eyes: AME 0.33, ALE 0.27, PME 0.57, PLE 0.47, POQ length 0.93, POQ posterior width 1.93, POQ anterior width 0.40. Anterior eye row slightly procurved, ALE on small tubercles (Fig. 19 b). Chelicerae: 4.27 length, three promarginal teeth, the median largest; retromargin with three equal equidistant teeth. Abdomen: length 8.25, width 6.38. Anterior lateral spinnerets conical, two-segmented, distal segment short, truncated. Legs: length of segments (femur + patella/tibia + metatarsus + tarsus = total length): pedipalp 3.19 + 2.10 + - + 2.75 = 10.04, I 7.98 + 11.04 + 7.18 + 3.86 = 30.06, II 7.98 + 10.37 + 6.65 + 3.72 = 28.72, III 7.58 + 8.65 + 6.65 + 3.72 = 26.6, IV 8.78 + 11.70 + 9.98 + 4.26 = 34.72. Leg formula 4123. Spination pattern: femur I p 0-0-2ap d 1-1-1, II p d1-0-d1 d 1-1-1 r 0-d1-d1, III p d1-0-d1 d 1-1-1 r d1-0-d1, IV p d1-0-d1 d 1-1-1 r 0-0-d1; patella II p 1, III p 1 r 1, IV p 1 r 1; tibia I p 0-0-1 v 2-2 -2ap, II p 1-0- 1 v r1-2-2, III p 1-0-1 d 0-1-0 r 1-0-1 v 2- 2 -2ap, IV p 1-0-1 r 1-0- 1 v p1-2-2ap; metatarsus I p 1ap r 1ap v 2-2 -1ap, II p 1ap r 1ap v 2-2 -1ap, III p 1-1-2ap r 1-1-2ap v 2-2 -1ap, IV p 1-1-2ap r 1-1-2ap v 2-2 -1ap.

Male. Unknown.

Variation. Range, mean ± SD. TL 14.64 – 20.62, 17.96 ± 1.95; CL 7.32 – 10.11, 9.10 ± 0.90; CW 5.59 – 7.71, 6.94 ± 0.65; TCR 1.40 – 1.51, 1.45 ± 0.04; n = 10.

Etymology. The specific name is a noun in apposition after the fire of the Moon in the Guarani language.

Natural history. The female holotype (who at the moment of capture carried an eggsac attached to the spinnerets) was found on a fallen trunk, in a dense white tubular retreat, similar to the retreat in the web of A. lagotis . The web lacked the horizontal mesh web described for A. lagotis (Santos and Brescovit, 2001) . The juvenile (MACN-Ar 20394) was collected in cracks on a rocky wall over a small water body, no web was observed there. The female illustrated in Fig. 5, was collected in a web, similar to that of A. lagotis, but smaller in proportion to the size of the spider (Gonzalo Rubio, personal communication).

Distribution. Known only from rain forest in Misiones province (Fig. 21).