Chthonius
Creators: name: Gardini, Giulio
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Pseudoscorpiones
Chthoniidae
Chthonius

description: [Chthonius (E.) giustii Callaini, 1981]
(Figs 98–105)
Chthonius giustii Callaini 1981: 309, figs Ia–g, IIa–b.
Type locality: France, Corsica, Dept. Haute-Corse, Corte, Forêt de Cervello (42°11ʹN 9°07ʹE). Distribution. Corsica.
Diagnosis (Ƥ). An eyed epigean Chthonius (Ephippiochthonius) from Corsica that differs from other species of the C. fuscimanus group in the following combination of characters: movable cheliceral finger without isolated subapical tooth (di); fixed chelal finger with 10–12 triangular teeth, at level of est-it, with 5–6 teeth occupying 0.1 mm (distance between successive apices 0.019–0.021 mm); length of chela 0.47–0.54 (3), 0.53–0.61 (Ƥ) mm, length of pedipalpal movable finger 0.28–0.31 (3), 0.30–0.35 (Ƥ) mm; chela 4.8–5.15 (3), 4.1–4.3 (Ƥ) times as long as deep; ratio of pedipalpal femur/carapace 1.1–1.2 (3Ƥ).
Type material examined. FRANCE— Corsica— 2 3 1 Ƥ (paratypes), “ Corsica, Bois de Cervello, muschi e terriccio di Arbutus sp., 21.IV.1980 ” “G. Callaini det., paratypus ” (1 3 1 Ƥ MSNG, unusable permanent microscope slides, left chela of female deformed; 1 3 MSNV, depository not stated by Callaini 1981: 315).
Other material examined. FRANCE— Corsica –1 3, Castagniccia, near Cervione, 4.VI.1982, A. Torchia & S. Zoia leg., sieved in Quercus ilex wood; 1 3 1 Ƥ, Foresta di Vizzavona, 1000–1400 m a.s.l., 28.V.1982, A. Torchia & S. Zoia leg., Fagus sylvatica wood.
Description of adults (Ƥ). Integument pigmented, carapace, tergites, chelicerae and pedipalps brown; lateral surfaces of carapace, cheliceral palm, ventrodistal surface of pedipalpal hand and base of movable chelal finger with weakly cuticular hispid granulation. Carapace 1.0–1.1, subquadrate; anterior margin (figs 98–99) dentate between median macrosetae, weakly prominent; ocular area as in fig. 100, anterior eyes with weakly convex lens (diameter 0.028 mm), posterior eyes reduced to cuticular smooth area, both eyes with tapetum; distance from anterior eyes to anterior margin of carapace 0.030 mm; chaetotaxy mm(or m) 4mm (or m):6:4:2:2 (18), macrosetae fine; length of anteromedian macrosetae 0.06–0.08 mm. Chaetotaxy of tergites I–X 4:4:4:4:6:6:6:6:6:4. Chaetotaxy of sternites II–X 10:(3)8(3):(2)7(2):8:6:6:6:6:7; genital opening of males flanked by 5–7 setae on each side. Chelicerae (figs 101–102) 2.0–2.1 times as long as broad, palm with 6 setae and 2 microsetae laterally; fixed finger with 6–9 teeth proximally reduced in size and 5–6 proximal tubercles; movable finger without isolated subapical tooth (di), with 5–7 teeth proximally reduced in size and 3–4 proximal tubercles; gl ratio 0.59–0.61; spinneret large and prominent, apically rounded, similar in both sexes; rallum with 11 blades; serrulae interior and exterior respectively with 12 and 14 blades. Coxal setae: pedipalp 5 (including 2 on manducatory process), I 3 + 3 marginal microsetae, II 4, III 5, IV 6; coxa II with 4–8 (mostly 5–6) coxal spines, coxa III with 2–5 (mostly 3) coxal spines; intercoxal tubercle bisetose. Pedipalp: femur 5.0–5.4 (3), 4.6–5.15 (Ƥ) times as long as broad; chela (figs 103– 105) 4.8–5.15 (3), 4.1–4.3 (Ƥ) times as long as deep; hand of chela 2.1–2.25 (3), 1.9–2.0 (Ƥ) times as long as deep, depressed at level of ib-isb; fixed chelal finger with 10–12 teeth with dental canals: the first distal tooth smaller, the 1–2 proximal teeth apically rounded, the others upright, large, triangular and weakly reclined; base of fixed finger with 5–7 microtubercles; tip of fixed finger with a modified accessory tooth (td) on antiaxial face; pedipalpal fixed finger at level of est-it with 5–6 teeth occupying 0.1 mm (distance between successive apices 0.019–0.021 mm); distal half of movable finger with 5–7 upright, large, triangular teeth with dental canals and 1 very small distal tooth; proximal half of movable finger with thick marginal lamina, weakly undulated, sometimes with vestigial teeth; coupled sensilla pc level with sb; trichobothria as in figs 104–105, eb-esb-ist placed mostly in a straight line, or with ist at level of esb or proximad of esb; basal apodeme of movable finger strongly sclerotized, squad, apically truncated; ratio of movable finger/hand of chela 1.2–1.4 (3), 1.2–1.3 (Ƥ); ratio of pedipalpal femur/ movable finger 1.2 (3Ƥ); ratio of pedipalpal femur/carapace 1.1–1.2 (3Ƥ).
Measurements (in mm). Body length 1.0–1.1. Carapace 0.28–0.33 × 0.26–0.30 (0.24–0.26 anteriorly) (3), 0.32–0.35 × 0.315–0.35 (0.29–0.30 anteriorly) (Ƥ). Chelicerae 0.22–0.25 × 0.11–0.12 (3), 0.26–0.30 × 0.13–0.15 (Ƥ), movable finger length 0.12–0.13 (3), 0.14–0.16 (Ƥ). Pedipalp: femur 0.33–0.36 × 0.06–0.07 (3), 0.37–0.43 × 0.07–0.09 (Ƥ); chela 0.47–0.54 × 0.095–0.11 (3), 0.53–0.61 × 0.12–0.145 (Ƥ); hand length 0.21–0.23 (3), 0.25– 0.29 (Ƥ); movable finger length 0.28–0.31 (3), 0.30–0.35 (Ƥ).
Remarks. Among the species of the Chthonius fuscimanus group, C. giustii is related to C. corsicus and C. siscoensis, both from Corsica. It differs from the epigean C. corsicus by its smaller size [length of chela 0.33–0.36 mm (3) in C. giustii, 0.655–0.67 mm (3) in C. corsicus], in the shape of pedipalpal hand (depressed at level of ibisb with a square profile in C. giustii, weakly depressed at level of ib-isb with a rectangular profile in C. corsicus) and in having less slender pedipalps [chela 4.8–5.15 (3) times as long as deep in C. giustii, 5.5–5.8 (3) in C. corsicus]. C. giustii differs from the hypogean C. siscoensis in most troglomorphic characters.
The above redescription of C. giustii incorporates the original one of Callaini (1981).
description: Published as part of Gardini, Giulio, 2013, A revision of the species of the pseudoscorpion subgenus Chthonius (Ephippiochthonius) (Arachnida, Pseudoscorpiones, Chthoniidae) from Italy and neighbouring areas, pp. 1-151 in Zootaxa 3655 (1) on pages 54-57, DOI: 10.11646/zootaxa.3655.1.1, http://zenodo.org/record/223358