Mesabolivar guaycolec Huber 2018, sp. n.

Mesabolivar guaycolec sp. n.

Figs 323–324, 359–364, 372–373

Mesabolivar “CAS 344”: Huber 2014: 139.

Diagnosis. Easily distinguished from most known congeners (except M. xingu, M. amanaye) by series of parallel ridges ventrally on procursus (Fig. 360). From M. xingu and M. amanaye by armature of male chelicerae (Figs 361–362; three pairs of frontal processes of distinctive shape and in distinctive pattern), and by shape of epigynum (square-shaped, with sclerotized round internal pouch visible through cuticle; Figs 363, 372) (female of M. xingu unknown).

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

Type material. ARGENTINA: Formosa: ♂ holotype, CAS (9058810), 5♂ 4♀ paratypes, CAS (9027305), 25 km N Formosa, Estancia Guaycolec [25.985°S, 58.16°W, 185 m a.s.l.], 26.ii.–10.iii. 1999 (S.L. Heydon, J.M. Ledford).

Other material. None

Description. Male (holotype)

MEASUREMENTS. Total body length 3.4, carapace width 1.4. Distance PME-PME 130 µm, diameter PME 120 µm, distance PME-ALE 100 µm, distance AME-AME 30 µm, diameter AME 50 µm. Sternum width/length: 0.95/ 0.55. Leg 1: 45.6 (11.7 + 0.5 + 11.5 + 19.9 + 2.0), tibia 2: 7.2, tibia 3: 5.2, tibia 4: 6.9; tibia 1 L/d: 88. Femora 1–4 width (at half length): 0.20, 0.20, 0.18, 0.18.

COLOR (in ethanol). Carapace ochre-yellow, with brown median mark including ocular area; clypeus not darkened; legs light brown, tips of femora and tibiae whitish, slightly darker rings on femora (subdistally) and tibiae (proximally and subdistally); abdomen pale gray, with darker internal marks dorsally and laterally, light brown mark in front of gonopore.

BODY. Habitus as in Figs 323–324; ocular area raised; carapace with distinct median furrow; clypeus and sternum unmodified.

CHELICERAE. With three pairs of frontal apophyses; only most proximal pair visible in lateral view (Figs 361– 362).

PALPS. As in Figs 359–360; coxa with retrolateral apophysis; trochanter barely modified; femur with retrolateral process proximally, widened distally; procursus with ~7 ventral parallel ridges, proximal ridges indistinct, procursus tip distinctive; genital bulb process mostly unsclerotized, with fine sclerotized tip.

LEGS. Without spines and curved hairs, few vertical hairs; retrolateral trichobothrium on tibia 1 at 2%; prolateral trichobothrium present on tibia 1; tarsus 1 with ~30 pseudosegments, indistinct.

Male (variation). Tibia 1 in three other males: 9.7, 11.5, 16.9.

Female. In general similar to male. Tibia 1 in three females: 7.3, 8.2, 8.2. Epigynum as in Figs 363, 372; anterior plate square-shaped, with medially slightly protruding posterior margin and sclerotized round internal pouch visible through cuticle, without external pocket; posterior plate large but weakly sclerotized and barely visible. Internal genitalia as in Figs 364, 373, with large pore-plates, distinctive posterior folds, and internal pouch originating from uterus externus and directed towards ventral cuticle.

Distribution. Known from type locality in Formosa Province (Argentina) only (Fig. 735).