Architis gracilis Santos sp. nov.

Figures 1–3, 11

Type material. Holotype: male from Reserva Extrativista Catuaba, Senador Guiomard, state of Acre, BRA- ZIL, 10o04’S 67o38’W, 2002, E.F. Morato coll. (IBSP 91473).

Etymology. The specific name is a Latin adjective meaning slender or thin, and refers to the small size and fragile appearance of this species.

Diagnosis. Architis gracilis Santos sp. nov. differs from all the remaining species of the genus by the combination of a DTP which is not curved retrolaterally, a large conductor and the exposed portion of embolus which is long and bent apically (Fig. 2).

Description. Male (based on holotype from Senador Guiomard, Brazil). Carapace orange, with a pair of longitudinal black stripes. Anterior eye row slightly procurved, with eyes equally sized and smaller than posterior eyes (Fig. 1). Clypeus orange, chelicerae orange with a frontal median black spot. Labium, endites and sternum orange. Legs orange, darker from basal third of femur to apex of tarsus. Pedipalpus orange, with a black ventral spot on trochanter and a black prolateral spot on apical third of femur. Pedipalpal patella and tibia black on prolateral surface. Abdomen orange, gently suffused with dark-grey and with a black ring around the base of spinnerets. Spinnerets and anal tubercle black (Fig. 1). Total length 2.9. Carapace 1.1 long, 1.0 wide. Tibia I length 2.3, II 2.0, III 1.7, IV 1.8. Abdomen 1.8 long, 0.7 wide. Pedipalpal tibia as long as cymbium. Ventral tibial apophysis strongly bent retrolaterally and acuminated. Ventral branch of retrolateral tibial apophysis absent, dorsal branch well developed, concave ventrally. Distal area of cymbium long and narrow. Subtegulum visible in baso-prolateral corner of cymbium. Median apophysis well developed and rounded (Figs 2–3).

Female. Unknown.

Natural history. The type specimen was collected by beating undergrowth foliage in a secondary forest.

Distribution. Known only from its type locality in western Brazilian Amazonia.