Mesabolivar macushi, Huber, 2018

Huber, Bernhard A., 2018, The South American spider genera Mesabolivar and Carapoia (Araneae, Pholcidae): new species and a framework for redrawing generic limits, Zootaxa 4395 (1), pp. 1-178 : 24-29

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).