Citharoceps Chamberlin, 1924

Giroti, Andre Marsola & Brescovit, Antonio Domingos, 2015, Revalidation of the spider genus Citharoceps Chamberlin, 1924 (Araneae, Segestriidae), ZooKeys 495, pp. 1-19 : 3-4

Taxon classification Animalia Araneae Segestriidae

Citharoceps Chamberlin, 1924 gen. reval.

Citharoceps Chamberlin, 1924: 607.

Type species.

Citharoceps fidicina Chamberlin, 1924

Diagnosis.

The genus Citharoceps is distinguished from other segestriid genera by the presence in males, females and immatures of a conspicuous stridulatory apparatus composed of two patches of grooves on both sides of cephalic region (Figs 1 A–C) and a stridulatory thorn located on the prolateral region of femur I (Figs 2 A–B; 5C, H; 7C, H). Citharoceps has a labium with the distal region narrowed (Fig. 1F; 9C), differing from Segestria (Fig. 9D; Giroti and Brescovit 2011: fig. 8) and Gippsicola (Fig. 9B), which have a nearly parallel-sided labium. It is distinguished from Ariadna (Fig. 9A) by the presence of a labium-sternum junction with equal or smaller length than the endite-sternum junction (Fig. 9C); by a ventral spine on the median region of male metatarsi I (Figs 5E; 7E), and by the females with an interpulmonary fold strongly sclerotized, forming a conspicuous median flap (Figs 4 D–E; 6C; 8D), which is absent in Ariadna (Fig. 10A).

Description.

Medium-sized synspermiata spiders (see Michalik and Ramírez 2014). Total length 5.0-11.92, carapace 2.64-4.44 long, 1.76-2.76 wide. Carapace and chelicerae coloration ranging from orange to dark reddish orange. Eyes bounded by dark outlines (Figs 5A, F; 7A, F). Endites orange to reddish orange; labium dark orange to dark reddish orange. Sternum orange to reddish orange, with darker margins (Figs 5B, G; 7B, G). Legs orange to reddish orange with pair I–II darker. Femur, patella and tibia I–II distally marbled with darker pigment (Figs 5 C–E, H–I; 7 C–E, H–I). Abdomen greyish, with a dorsal pattern composed by dark chevrons, and irregularly distributed dark spots on the ventral region (Figs 5 A–B, F–G; 7 A–B, F–G). Carapace oblong, with cephalic region narrower than thoracic region, and sparsely distributed setae usually concentrated in the cephalic region. Posterior eyes positioned in a slightly recurved line (Figs 1 A–B; 5A, F; 7A, F). Chelicerae: with prominent basal lateral ridge (Fig. 1D), and lateral proximal depression near the carapace (Fig. 1B); cheliceral teeth composed by three promarginal and one retromarginal, all with ridged cuticle (Figs 1E, G). Labium with 2/3 of the length of the endite, separated from the sternum by a partially membranous suture (Figs 1F, 9C; Labarque and Ramírez 2012: 6). Sternum longer than wide, with anterior region truncated and procurved anterior margin (Figs 5B, G; 7B, G). Male palp with a short and distally notched cymbium, piriform bulb and a hook-like embolus, with small tubercles (Fig. 4 A–C). Female palps with one articulated claw, followed by scattered prolateral spines (Fig. 2C). Legs robust (Figs 5 C–D, H–I; 7 C–D, H–I). Tarsal organ exposed (following Labarque and Ramírez 2012) with edges, and usually three rimmed receptors (Fig. 2E; following Platnick et al. 2012). Trichobothria on the dorsal subdistal region of metatarsi I–IV, dorsal subproximal and subdistal region of tibia I–IV, and dorsal region of the male and female palpal tibia; trichobothrial bases with a transverse ridge, curved inwards; trichobothrial shaft filiform (Fig. 2F). Legs with three tarsal claws, paired claws pectinated, and unpaired one with only a small tooth (Fig. 2D); chemosensory setae on the distal ventral region of tarsi I–II in males (Fig. 2D, G; according to Foelix and Chu-Wang 1973: figs 17 a–b). Preening comb of metatarsi IV with 5-7 spines (Fig. 2H). Abdomen uniformly hairy, longer than wider (Figs 5 A–B, F–G; 7 A–B, F–G). Spinnerets: ALS with three segments, the basal segment crossed by a diagonal membranous stripe (Fig. 3A), and one MAP spigot with 8 PI (Fig. 3D); PMS with just one mAP spigot (Fig. 3C); PLS with 4 AC spigots (Fig. 3B). Colulus triangular and pilose (Fig. 3E). Internal female genitalia: anterior receptaculum bilobated with a hyaline external cuticle, a short dorsal lobe, and a small plate of glandular ducts restricted to the ventral and lateral region of the dorsal lobe; posterior receptaculum membranous, with pores (Figs 4 D–G; 6 C–D; 8 C–D).