Thrandina cosanga, sp. nov.

(Figs 25–29, 37–42)

Type material. Holotype male in QCAZ with data: " ECUADOR: Napo: Vinillos, near Cosanga . S 0.6025 W 77.8508. 2080 m elev. 29–30 October 2010. W & D Maddison, M Vega, M Reyes. WPM#10-036", "Male W606", UBC-SEM AR00195

Etymology. Named after the type locality.

Diagnosis. Closely similar to T. bellavista, from which it can be distinguished by the narrower tip of embolus (Fig. 25), the more robust median apophysis (Fig. 27), and the lack of two large pale spots on the back of the abdomen. Although there are few records, T. cosanga and T. bellavista may be allopatric, with T. cosanga on the eastern slopes of the Andes. Like T. bellavista, T. cosanga differs in many respects from T. parocula, including the smaller median apophysis, embolus with a single curve, cymbium clothed entirely in white setae (compare Figs 39 and 51), paler base of the first leg metatarsus (compare Figs 38 and 48), and epigynal opening more anteriorly placed.

Description. Male (holotype). Carapace length 2.5; abdomen length 2.5. PME large. Chelicerae not particularly enlarged, with 3 promarginal and 2 retromarginal teeth. Palpus (Figs 25–27): curved embolus arises prolaterally. Median apophysis large, shaped almost like a human ear. Conductor pale, triangular, between embolus and median apophysis. Tibia of first leg with 3 pairs of ventral macrosetae; first metatarsus with 3 prolateral and 2 retrolateral macrosetae. Colour (Figs 37–40): In general dark brown. Thorax with pale medial longitudinal stripe. Palpus dark but with white setae covering almost the entire cymbium, dorsum of the tibia, and parts of the patella. The extreme prolateral edge of the cymbium has dark setae. Legs medium to dark brown, the first legs especially dark, with paler patella and pale annulae at the bases of the metatarsi and tarsi. Abdomen with paler chevrons.

Female (paratype in UBC-SEM, #UBC–SEM AR00196, from: ECUADOR: Napo: Cosanga, Yanayacu Biological Station, forest. S 0.600 -1 W 77.888 -890. 2100 m elev. 7 Nov. 2010. W & D Maddison, M Vega, M Reyes. WPM#10-058). Carapace length 2.0; abdomen length 2.6. PME large. Chelicerae with 3 promarginal and 2 retromarginal teeth. Palp with tarsal claw. Tibia of first leg with 3 pairs of ventral macrosetae; first metatarsus with 3 prolateral and 2 retrolateral setae. Epigynum (Fig. 28–29) with openings in single round anterior cavity. Colour (Figs 41–42): as in male except first legs not so dark.

Additional material examined. 7 males, 8 females, in UBC-SEM, from: ECUADOR: Napo: Reserva Ecologica Antisana, Sendero Jumandy. S 0.624 -5 W 77.840 - 2. 2260 m elev. 29 Oct. 2010. W & D Maddison, M Reyes. WPM#10-035 (1 male); ECUADOR: Napo: Vinillos, near Cosanga . S 0.6025 W 77.8508. 2080 m elev. 29–30 October 2010. W & D Maddison, M Vega, M Reyes. WPM#10-036 (3 male and 1 female paratypes, and an additional 2 males and 3 females); ECUADOR: Napo: Cosanga, Yanayacu Biological Station, forest. S 0.600 -1 W 77.888 -890. 2100 m elev. 7 Nov. 2010. W & D Maddison, M Vega, M Reyes. WPM#10-058 (1 male paratype, 1 female paratype, and 3 additional females).

Natural history. All specimens were found in moist forests, usually on mossy tree trunks and branches. Partial courtship behaviour was observed once (Fig. 38, video http://www.youtube.com/watch?v=ZtB4G4fXH0k). The first legs were held down and forward, and the palpi angled outward over the femora of the first legs. The male flickered the palpi and first legs occasionally. Another video of a living male is available: http://www.youtube.com/watch?v=-8Xx8rN5IKU.