Carapoia tapajos sp. n.

Figs 561–563, 573–580, 631–632

Diagnosis. Easily distinguished from known congeners by shape of procursus (strongly curved, distinctive bifid tip; Figs 574–577), by bulbal processes (slender apophysis with proximal serration, large dorsal protrusion; Fig. 573), by armature of male chelicerae (pair of frontal apophyses near median line close to laminae and pair of low lateral humps more proximally; Fig. 578), and by female external and internal genitalia (semicircular epigynum with distinctive scape-like process carrying pocket; large oval pore-plates consisting of many platelets; Figs 579– 580, 631–632).

Etymology. The specific name is derived from the type locality; noun in apposition.

Type material. BRAZIL: Pará: ♂ holotype, 1♀ paratype, UFMG (21542–43), and 3♂ 5♀ paratypes, ZFMK (Ar 19237), Floresta Nacional de Tapajós, km 67, ‘site 1’ (2.847°S, 54.972°W), 180 m a.s.l., 15.x.2016 (B.A. Huber, L.S. Carvalho).

Other material examined. BRAZIL: Pará: 2♀ 1 juv. in pure ethanol, ZFMK (Br 16-262), same data as types . 1♂ 4♀, ZFMK (Ar 19238), Floresta Nacional de Tapajós, km 67, ‘site 2’ (2.875°S, 54.941°W), 190 m a.s.l., 15.x.2016 (B.A. Huber, L.S. Carvalho).

Description. Male (holotype)

MEASUREMENTS. Total body length 1.9, carapace width 0.9. Distance PME-PME 60 µm, diameter PME 75 µm, distance PME-ALE 60 µm, distance AME-AME 10 µm, diameter AME 25 µm. Sternum width/length: 0.57/ 0.40. Leg 1: 20.8 (4.6 + 0.3 + 5.0 + 9.5 + 1.4), tibia 2: 3.1, tibia 3: 2.3, tibia 4: 2.7; tibia 1 L/d: 71. Femora 1–4 width (at half length): 0.15, 0.16, 0.16, 0.16.

COLOR (in ethanol). Carapace ochre-yellow with brown median band and lateral margins, ocular area only laterally brown; clypeus brown; sternum brown; legs light brown, without dark rings, tips of femora and tibiae lighter; abdomen bluish gray, many internal dark marks dorsally and laterally, ventrally with large brown genital plate and brown book lung covers, short median mark behind genital plate.

BODY. Habitus as in Figs 561–562; ocular area slightly raised; carapace with distinct median furrow; clypeus unmodified; sternum unmodified.

CHELICERAE. As in Fig. 578, pair of frontal apophyses near median line close to laminae and pair of low humps more proximally.

PALPS. As in Figs 573–574; coxa with small retrolateral apophysis; trochanter barely modified; femur with large retrolatero-ventral process proximally with small sclerite pointing towards prolateral, small dorsal hump; procursus strongly curved, with distinctive bifid tip (Figs 575–577); genital bulb with slender apophysis with serrated sclerotized ridge, large mostly membranous dorsal protrusion.

LEGS. Without spines, without curved hairs, few vertical hairs; retrolateral trichobothrium on tibia 1 at 3.5%; prolateral trichobothrium present on tibia 1; tarsus 1 with ~20 pseudosegments, poorly visible in dissecting microscope.

Male (variation). Tibia 1 in four other males: 4.3, 4.7, 5.1, 5.1.

Female. In general similar to male (Fig. 563). Tibia 1 in ten females: 3.5–3.9 (mean 3.8). Epigynum as in Figs 579, 631; anterior plate semicircular, dark brown, weakly protruding, with distinctive mostly membranous scapelike process carrying pocket; with pair of diverging sclerites in membrane behind anterior plate; narrow posterior plate. Internal genitalia as in Figs 580, 632, with large oval pore-plates consisting of many platelets.

Natural history. The spiders were collected from leaf litter and small cavities in the ground. Their small webs usually extended beyond the shelter in which males and females were often found together. When disturbed they vibrated very rapidly and ran away quickly.

Distribution. Known from type locality in Pará state (Brazil) only (Fig. 741).