Mesabolivar macushi Huber 2018, sp. n.

Mesabolivar macushi sp. n.

Figs 90–97, 104–105, 128–129

Diagnosis. Easily distinguished from similar congeners (M. aurantiacus, M. cyaneus, M. spinosus) by shape of procursus (Figs 96–97; short distal sclerite with small subdistal parallel side branch), by armature of male chelicerae (Figs 92–93; pair of strongly curved, blade-shaped frontal apophyses), and by female external and internal genitalia (Figs 94–95, 128–129; epigynum without pocket, without processes; small pore-plates; weakly sclerotized median sac-like structure).

Etymology. The specific name honors the Macushi, an indigenous people living in eastern Venezuela, southern Guyana, and northern Brazil; noun in apposition.

Type material. VENEZUELA: Bolívar: ♂ holotype, ZFMK (Ar 18962), forest near base of Salto Angel (5°58.0’N, 62°31.7’W), ~ 720 m a.s.l., domed webs near ground, 7.xii.2002 (B.A. Huber).

Other material examined. VENEZUELA: Bolívar: 1♀ 2 juvs, together with holotype.

Description. Male (holotype)

MEASUREMENTS. Total body length 3.7, carapace width 1.7. Distance PME-PME 180 µm, diameter PME 170 µm, distance PME-ALE 120 µm, distance AME-AME 35 µm, diameter AME 50 µm. Sternum width/length: 1.15/ 0.85. Leg 1: 61.7 (14.7 + 0.7 + 14.1 + 27.9 + 4.3), tibia 2: 9.1, tibia 3: 6.8, tibia 4: 8.7; tibia 1 L/d: 88. Femora 1–4 width (at half length): 0.21, 0.23, 0.26, 0.23.

COLOR (in ethanol). Carapace ochre-yellow with large brown mark covering most of posterior half, ocular area brown, clypeus not darkened, sternum light brown; legs light brown, without dark or light rings; abdomen ochregray, with many dark internal marks dorsally and laterally, with small light brown plate in front of gonopore.

BODY. Habitus similar to M. aurantiacus (cf. Figs 78, 80); ocular area raised; carapace with distinct median furrow; clypeus and sternum unmodified.

CHELICERAE. With pair of strongly curved, blade-shaped frontal apophyses (Figs 92–93) with finely granulated surface.

PALPS. As in Figs 90–91; coxa with retrolateral apophysis; trochanter with short rounded ventral process; femur with retrolateral apophysis proximally, widened distally; tarsus with three small dorsal processes; procursus S-shaped, short distal process with small subdistal parallel side branch (Figs 96–97); genital bulb process slender, with weakly sclerotized bifid distal process (Figs 104–105).

LEGS. Without spines and curved hairs, few vertical hairs; retrolateral trichobothrium on tibia 1 at 3%; prolateral trichobothrium present on tibia 1; tarsus 1 with ~60 pseudosegments, distally fairly distinct.

Female. In general similar to male; tibia 1: 12.4. Epigynum as in Figs 94, 128; anterior plate without pocket, with very indistinct and shallow median furrow, lateral parts more heavily sclerotized but not elevated; in lateral view slightly protruding towards posterior edge; posterior plate large, simple. Internal genitalia as in Figs 95, 129, with small pore-plates, weakly sclerotized median sac.

Natural history. The spiders were collected from domed webs hidden in sheltered cavities of the ground. Distribution. Known from type locality in Bolívar state (Venezuela) only (Fig. 725).