Chthonius pygmaeus Beier 1934
Creators: name: Gardini, Giulio
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Pseudoscorpiones
Chthoniidae
Chthonius
Chthonius pygmaeus

description: Chthonius pygmaeus Beier, 1934
(Figs 358–372, 408)
Chthonius (Neochthonius) pygmaeus Beier, 1934: 53, fig. 1.
Chthonius (Chthonius) carinthiacus: Gardini 2004: 125 (in part, see C. carinthiacus).
Type locality: Slovakia, Banská Bystrica, Železná Breznica (48°37’N, 19°01’E).
Distribution. Austria, Switzerland, Italy (Eastern Alps), Slovenia, Croatia, Hungary, Slovakia.
Diagnosis (♂ ♀). An eyed epigean Chthonius that differs from other species of the ischnocheles group in the following combination of characters: anterior margin of carapace without preocular microsetae; posterior margin of carapace with 2 macrosetae, without lateral microsetae; chelicerae with 1 lateral microseta; palpal hand mostly darker than the fingers, slightly conical in dorsal view; chela length 0.63–0.98 mm; movable chelal finger 0.395– 0.60 mm; chelal fingers with contiguous, cuspidate and slightly reclined teeth, mainly with a convex distal side; fixed and movable chelal fingers with 31–52 and 26–38 teeth respectively; fixed finger at level of est-it with 7–11 (♂) or 6–9 (♀) teeth occupying 0.1 mm, distance between successive apices 0.008 –0.014 (♂) or 0.009 –0.019 (♀) mm.
Type material examined. Slovakia — 2 ♂ (paratypes, in poor condition), “ Baris m. Vihnye völgy. 1932.V.12. Lg. Dudich ” “ Chthonius pygmaeus n. sp. Paratypen ♂ det. Beier ” “1293 / tr., regen. 1997” (NMW).
Other material examined. AUSTRIA — Kärnten — 1 ♂ 1 ♀ (det. M. Beier), Gazarka, nördl. Klopeiner See, [46°36’43”N, 14°35’38”E], 16.VII.1947, Schweiger leg. (NMW).
CROATIA — Istria — 1 ♂ (C. carinthiacus, det. G. Gardini), Učka (Monte Maggiore), 800 m a.s.l., 17.VI.1982, M. Seriani leg.
ITALY — Venezia Giulia: Gorizia Prov. — 1 ♂ 2 ♀, Cormons, Bosco Romagno, 12.XII.1982, M. Seriani leg., leaf litter; 1 ♂ 1 ♀, Doberdò del Lago, Lago di Doberdò, 12.IV.1981, E. Bognolo leg.; 1 ♂ 1 ♀, Gorizia, Devetachi, 1982, M. Seriani leg.; 8 ♂ 8 ♀ 6 T 3 D, Monfalcone, marsh of Fiume Cavana, 1 m a.s.l., 29.XI.2001, G. Tomasin & F. Stoch leg., damp meadow (MFNB). Venezia Giulia: Trieste Prov. — 1 ♀, Monrupino, 3.I.1982, M. Seriani leg., hollow on Quercus; 2 ♂ 6 ♀, Opicina, Banne, 15.XII.1982, M. Seriani leg.; 2 ♂ 1 ♀ 1 T, Sgonico, Grotta dell’Orso 7 VG/TS, 30. VIII.1987, G. Gardini & R. Rizzerio leg., cave entrance; 1 ♀, id., 29.III.1991, M. Bodon leg., cave entrance. Friuli: Pordenone Prov. — 1 ♀ (C. baccettii, det. G. Callaini), Clauzetto, Pradis, 10.IV.1983, M. Seriani leg. (MSNV); 1 ♀ (C. baccettii, det. G. Callaini), Maniago, Colvere, 17. V.1982, M. Seriani leg. (MSNV); 1 ♀, Tramonti di Sotto, Bosco Selvaz, 21. VI.1987, L. Dreon leg. Friuli: Udine Prov. — 1 ♀, Ampezzo, marsh of Cima Corso, 839 m a.s.l., 12.X.2001, G. Colombetta leg., pitfall trap in wood (MFNB); 1 ♂ 1 T, Bertiolo, Risorgive di Virco, 23 m a.s.l., 31.III.2001, A. Zanetti, A. Tagliapietra, G. Tomasin & G. Governatori leg., basic peat (MFNB); 2 ♂, Carlino, 29.XII.1980, M. Seriani leg., Querco-Carpinetum; 2 ♂ 2 ♀ 1 T, Cervignano, Bosco Pradiziolo, 9.I.1982, M. Seriani leg., Querco-Carpinetum; 7 ♂ 1 ♀ 1 T, id., 16.I.1983, M. Seriani leg., Quercus wood; 6 ♂ 8 ♀, id., 4. III.1983, M. Seriani leg.; 2 ♂ 3 ♀, id., 6. V.1983, M. Seriani leg.; 1 ♀, id., 21. VI.1986, M. Seriani leg.; 1 ♀, Claut, Alta Val Cellina, Pian de Cea, towards Casera Casavento, 930 m a.s.l., 30. V.2002, A. Dall’Asta leg., beech wood (MFNB); 4 ♀, id., 17. VI.2002, A. Dall’Asta leg., beech wood (MFNB); 1 ♀ 1 T, id., 1.VII.2002, A. Dall’Asta leg., beech wood (MFNB); 2 ♂, Claut, Val Settimana, between Stalle Parigina and Stalla Pustrin, 650 m a.s.l., 16. V.2002, A. Dall’Asta leg., beech wood (MFNB); 1 ♂ 1 ♀, id., 30. V.2002, A. Dall’Asta leg., beech wood (MFNB); 2 ♀, id., 17. VI.2002, A. Dall’Asta leg., beech wood (MFNB); 4 ♀, id., 1.VII.2002, A. Dall’Asta leg., beech wood (MFNB); 2 ♀, id., 13.VII.2002, A. Dall’Asta leg., beech wood (MFNB); 3 ♂ 5 ♀ 1 T, id., 29.VII.2002, A. Dall’Asta & L. Lapini leg. (MFNB); 1 ♂ 1 ♀, id., 13.VII.2002, A. Dall’Asta leg., beech wood (MFNB); 1 ♀, Fagagna, Quadris, 171 m a.s.l., 21. VI.2001, G. Colombetta leg., damp wood (MFNB); 6 ♂ 1 ♀, Gonars, Paludi del Corno, 15 m a.s.l., 1.IV.2001, A. Zanetti, A. Tagliapietra, G. Tomasin & G. Governatori leg., basic peat (MFNB); 2 ♂ 1 ♀ 2 T, id., 21. VI.2001, G. Colombetta leg., pitfall traps in wood and basic peat (MFNB); 2 ♂ 8 ♀ 2 T 3 D, id., 23.XI.2001, G. Tomasin leg., basic peat (MFNB); 1 ♂ 4 ♀, Lusevera, Alta Val Torre, near Case Tacia, 840 m a.s.l., 26. VIII.1992, M.M. Giovannelli leg., beech wood (MFNB); 1 ♂, Lusevera, Alta Val Torre, Isola Torrente Mea, 700 m a.s.l., 2.IX.1992, G. Governatori & C. Luppi leg. (MFNB); 6 ♀, Passo di Tanamea, 1000 m a.s.l., 5. VIII.1992, G. Governatori leg., beech wood (MFNB); 1 ♀ 1 T, id., 2.IX.1992, G. Governatori leg., beech wood (MFNB); 1 ♀, id., 12.IX.2006, L. Dorigo leg., beech wood (MFNB); 4 ♂ 1 ♀, id., 6. VI.2007, L. Dorigo leg., beech wood (MFNB); 2 ♂ 2 ♀, id., 12.VII.2007, L. Dorigo leg., beech wood (MFNB); 1 ♂, id., 29. VIII.2007, L. Dorigo leg., beech wood (MFNB); 2 ♀, id., 4.X.2007, L. Dorigo leg., beech wood (MFNB); 1 T, id., 20.XI.2007, L. Dorigo leg., beech wood (MFNB); 2 T, Lusevera, Plan di Tapou, 900 m a.s.l., 17.XI.2005, L. Dorigo & G. Tomasin leg., beech wood (MFNB); 1 ♂ 4 T, id., 6. VIII.2006, G. Colombetta & L. Dorigo leg., beech wood (MFNB); 2 ♀, id., 5.X.2006, G. Colombetta leg., beech wood (MFNB); 1 ♂ 1 ♀, Lusevera, Passo di Tanamea, 1050 m a.s.l., 7.XI.1992, G. Governatori leg., beech wood; 3 ♂ 1 ♀, Lusevera, near Passo di Tanamea, Valle del Rio Bianco, 800 m a.s.l., 6.X.1997, G. Governatori leg., beech wood; 1 ♀, Malborghetto Valbruna, N slope of Monte Montasio, 1400 m a.s.l., 25. VIII.1990, G. Governatori leg., beech wood (MFNB); 1 ♂, id., 1010 m a.s.l., 27.IX.1990, G. Governatori leg., mixed beech wood (MFNB); 3 ♀, Malborghetto Valbruna, Malga Saiseia, 1000 m a.s.l., 16. VI.1994, R. Poggi leg. (MSNG); 1 ♂ 3 ♀, Moggio Udinese, Stavoli Cuel Lung Alto, slope of Monte Zovet, 700 m a.s.l., 19. VI.2001, G. Governatori leg., pitfall traps in beech wood (MFNB); 6 ♀, id., 16.VII.2001, A. Dall’Asta leg., pitfall traps in beech wood (MFNB); 1 ♂ 1 ♀, id., 20. VIII.2001, G. Governatori leg., pitfall traps in beech wood (MFNB); 1 ♂, id., 31. V.2002, A. Dall’Asta & G. Governatori leg., beech wood (MFNB); 2 ♂ 1 ♀ 5 T, Moggio Udinese, Stavoli Tugliezzo, Rio Lavarie, 470 m a.s.l., 30.X.2001, G. Governatori &A Dall’Asta leg., beech wood (MFNB); 2 ♂, Muzzana, 15.X.1982, M. Seriani leg., Querco-Carpinetum; 1 ♂ 1♀ 3 T (together with 1 ♀ of C. carinthiacus), Paderno, Fiume Natisone, 90 m a.s.l., 23.IX.1983, M. Bodon leg.; 1 ♂, Pontebba, near Pietratagliata, 600 m a.s.l., 16. VI.1994, R. Poggi leg. (MSNG); 1 ♀, Resia, Lischiazze, 580 m a.s.l., 8. VI.1997, F. Gasparo leg., beech wood; 2 ♂ 4 ♀, Resia, near Uccea, 780 m a.s.l., 1. VI.1986, C. Torti & S. Zoia leg., beech wood; 6 ♂ 2 ♀, Resia, Sella Carnizza, 1080 m a.s.l., 19. VI.2001, G. Governatori & A. Dall’Asta leg., beech wood (MFNB); 1 ♀, id., 16.VII.2001, A. Dall’Asta leg., beech wood (MFNB); 1 ♀, id., 20. VIII.2001, G. Governatori leg., beech wood (MFNB); 1 ♂, id., 17.VII.2002, A. Dall’Asta & L. Merluzzi leg., beech wood (MFNB); 1 ♀, id., 9. VIII.2002, A. Dall’Asta & L. Lapini leg., beech wood (MFNB); 1 ♀, Resia, Clen, near Casera Coot, Jamma, 950 m a.s.l., 30.X.2001, A. Dall’Asta & G. Governatori leg., beech wood (MFNB); 3 ♀, Resia, Clen, between Casera Coot and Slatina Superiore, 1000 m a.s.l., 19. VI.2001,A. Dall’Asta & G. Governatori leg., beech wood (MFNB); 6 ♂ 14 ♀ 2 T, id., 20. VIII.2001, G. Governatori leg., pitfall traps in beech wood (MFNB); 1 ♂ 5 ♀, id., 26.IX.2001, A. Dall’Asta leg., pitfall traps in beech wood (MFNB); 1 T, id., 30.X.2001, G. Governatori leg., pitfall trap in beech wood (MFNB); 2 ♀, id., 26.VII.2002, A. Dall’Asta leg., beech wood (MFNB); 1 ♂ 1 ♀, id., 21.IX.2002, A. Dall’Asta leg., beech wood (MFNB); 2 ♂ 5 ♀ 3 T, Resia, Val Uccea, near Casera Malicuc, 760 m a.s.l., 20. VIII.2001, G. Governatori leg., beech wood (MFNB); 1 ♂ 2 ♀, id., 27.IX.2001, A. Dall’Asta leg., beech wood (MFNB); 1 ♂, Resia, Val Uccea, near Stalli Rasuga, 905 m a.s.l., 14. VIII.2007, G. Colombetta & L. Dorigo leg., beech wood (MFNB); 1 ♂ 1 ♀ 1 T, id., 16.X.2007, P. Glerean & L. Dorigo leg., beech wood (MFNB); 1 ♀, id., 29. V.2008, L. Dorigo leg., beech wood (MFNB); 2 ♂ 3 ♀, Resia, Val Uccea, near Stalli Tanatemea, 980 m a.s.l., 2. VIII.2006, G. Colombetta & L. Dorigo leg., beech wood (MFNB); 1 ♀ 1 T, id., 1.IX.2006, G. Colombetta leg., beech wood (MFNB); 1 ♀, id., 7.XI.2006, G. Colombetta leg., beech wood (MFNB); 1 ♀, id., 15. V.2007, G. Colombetta & L. Dorigo leg., beech wood (MFNB); 1 ♀, id., 12.VII.2007, G. Colombetta leg., beech wood (MFNB); 1 T, Resia, Val Uccea, near Torrente Uccea, 587 m a.s.l., 17.XI.2005, L. Dorigo & G. Tomasin leg., near the river (MFNB); 11 ♂ 2 ♀ 2 T, Rivignano, Risorgive Zarnicco, 13 m a.s.l., 31.III.2001, A. Zanetti, A. Tagliapietra, G. Tomasin & G. Governatori leg., basic peat (MFNB); 1 ♂, id., 19. VI.2001, G. Colombetta leg., basic peat (MFNB); 2 ♀, id., 16.X.2001, G. Colombetta leg., basic peat (MFNB); 6 ♂ 3 ♀ 2 T, id., 26.XI.2001, G. Tomasin & F. Stoch leg., basic peat (MFNB); 1 ♂, near Savogna, 28. VI.1994, S. Zoia leg., beech wood; 1 ♂, Sella Nevea, tributary of Torrente Raccolana, 8. V.1981, E. Bognolo leg.; 2 ♀, Sella Nevea, ENE slope of Monte Canin, 840 m a.s.l., 2.XI.1990, G. Governatori leg., beech wood (MFNB); 1 ♀, id., NE slope of Monte Canin, 1220 m a.s.l., 14. VI.1991, G. Governatori leg., subalpine Salicetum (MFNB); 1 ♀, Talmassons, Risorgive di Flambro, 22 m a.s.l., 31.III.2001, A. Zanetti, A. Tagliapietra, G. Tomasin & G. Governatori leg., Quercus robur wood (MFNB); 4 ♂, id., 19. VI.2001, G. Colombetta leg., pitfall traps (MFNB); 4 ♂, id., 16.X.2001, G. Colombetta leg., pitfall traps (MFNB); 3 ♂ 1 ♀, Tarvisio, near Lago del Predil, 1000 m a.s.l., 26. V.1986, S. Zoia leg.; 2 ♂ 2 ♀, Venzone, Monte Plauris, near Malga Confin, 1315 m a.s.l., 19. VI.2007, G. Colombetta & L. Dorigo leg., beech wood (MFNB); 1 ♂ 1 D, id., 25.VII.2007, G. Colombetta & L. Dorigo leg., beech wood (MFNB); 1 T, Venzone, Monte Plauris, near Casera Ungarina, 1325 m a.s.l., 20. VI.2006, G. Colombetta & L. Dorigo leg., beech wood (MFNB); 1 ♂, id., 2. VIII.2006, G. Colombetta & L. Dorigo leg., beech wood (MFNB); 1 ♂, id., 1.IX.2006, G. Colombetta & L. Dorigo leg., beech wood (MFNB); 2 ♂ 2 T, Venzone, Val Verzonassa, Rio Bruschie near Casera Frassin, 630 m a.s.l., 29. V.2008, L. Dorigo leg., beech wood (MFNB); 1 T, id., 9.X.2007, G. Colombetta leg., beech wood (MFNB); 1 ♀, Verzegnis, Sella Chianzutan, 954 m a.s.l., 1. VI.1986, R. Poggi leg. (MSNG); 2 ♂ 2 ♀, Codroipo, Sorgente Codroipo, 30. V.1986, M.G. Paoletti leg. Veneto: Belluno Prov. — 1 ♀ (C. ischnocheles, det. M. Beier), Cadore, [no date, G. Marcuzzi leg.] (MZUP); 1 ♀ (C. tenuis, det. M. Beier), Cadore, [no date, G. Marcuzzi leg.], leaf litter Fagus wood (MZUP); 1 ♀ (C. pygmaeus carinthiacus, det. M. Beier), Cadore, [no date, G. Marcuzzi leg.] (MZUP); 1 ♂ (C. pygmaeus carinthiacus, det. M. Beier), Cadore [no date, G. Marcuzzi leg.], (MZUP). Veneto: Treviso Prov. — 36 ex. (C. Rayi, det. G. Canestrini), Trevisano, 1873 (MZUP); 12 ex. (C. Rayi, det. G. Canestrini), Treviso, 1873 (MZUP). Veneto: Verona Prov. — 1 ♂ 1 T, Fumane, Cavalo, 600 m a.s.l., 21.XI.1998, R. Monguzzi leg. (RMM). Veneto: Vicenza Prov. — 2 ♂ 6 ♀ (C. baccettii, det. G. Callaini), Monte Grappa, 13.VII.1980, C. Bellò leg. (MSNV). Trentino: Trento Prov. — 1 ♀, Trento, Monte Celva, 19.IX.2019, N. Massimo leg. (NMM). Lombardy: Bergamo Prov. — 1 ♂ 1 ♀, Orezzo, Gazzaniga, Val Dé, 9.III.2000, R. Monguzzi leg. (RMM). Lecco Prov. — 1 ♂ 1 ♀, near Civate, 700 m a.s.l., 12. V.1912, S. Zoia leg.; 1 ♂ 3 ♀, Lecco, near Ballabio, 550 m a.s.l., 29.I.1994, S. Zoia leg.; 1 ♂ 1 ♀ 1 T, Lecco, Monte Barro, 800 m a.s.l., 24.XI.1990, S. Zoia leg.; 1 ♀, Primaluna, Val di Contra, 20. V.2010, G. Goggi leg. (GGI); 4 ♀, Val di Contra, 12.X.2010, G. Goggi leg. (GGI).
SLOVENIA — Gorenjska regija — 1 ♂, Triglavski narodni park, 1000 m a.s.l., 6. VIII.1995, S. Vit leg. Jugovzhodna Slovenija regija — 2 ♀, Ribnica, Dolenja vas, near Jasnica, 577 m a.s.l., 3. V.2008, S. & T. Novak leg., Picea and Fagus wood; 1 T, Kočevski Rog, near Novo Mesto, 750 m a.s.l., 7. VIII.2007, S. Zoia leg., mixed wood. Notranjsko-Kraška regija — 1 ♂ 3 ♀ (C. carinthiacus, det. G. Gardini), Kalič near Postojna, 780 m a.s.l., 10. V.1992, F. Gasparo leg. Obalno-Kraška regija — 4 ♂ 3 ♀ 1 T (C. carinthiacus, det. G. Gardini), Sežana, Pliskovica, 11.III.1984, M. Seriani leg.; 2 ♂ 1 ♀ 1 T, Škocjanske Jame (= San Canziano), 29. VIII.1987, G. Gardini & R. Rizzerio leg., entrance. Spodnjeposavska regija — 2 ♂ 2 ♀, Brežice, 28. VIII.1987, G. Gardini & R. Rizzerio leg. Zasavska regija — 1 ♂, Cemšeniška planina, Sv. Primož, 21.VII.2002, S. & T. Novak leg.
SWITZERLAND — Ticino — 2 ♂ 1 ♀ 1 T, Monte Generoso, Cribbietta, 350 m a.s.l., 6.V.1987, G. Cotti leg., under Ulmus; 3 ♂ 1 T, Monte Generoso, Val Corta, 860 m a.s.l., G. Cotti leg., mixed wood; 1 ♂ 2 ♀ 1 T, Monte Generoso, Castellaccio, Val Molino, 420 m a.s.l., 14.V.1987, G. Cotti leg., mixed wood with Ulmus.
Description of adults (♂ ♀). Integument pigmented, carapace, tergites, chelicerae and chelal hand brown; weak hispid granulation on lateral surface of carapace, on cheliceral palm, on base of fixed chelal finger and on dorsodistal surface of chelal hand. Carapace (Fig. 360) almost square shaped, moderately constricted posteriorly, 0.9–1.0 times longer than broad; anterior margin between median macrosetae strongly denticulate, with weakly prominent epistome in both sexes (Figs 358–359); ocular area as in fig. 360, anterior bulging eyes with convex lens (diameter 0.04–0.05 mm), posterior ones reduced, at most with flat lens; distance from anterior eyes to anterior margin of carapace 0.020 –0.035 mm, distance from anterior to posterior eyes 0.04–0.05 mm, all eyes with tapetum; chaetotaxy 4:6:4:2:2(18); length of anteromedian macrosetae 0.085–0.12 mm. Chaetotaxy of tergites 4:4:4:4:6:6:6:6:1T2T1:4: 1T2T1:0. Chaetotaxy of sternites II–X: 10–11:(2–3)7–10(2–3):(2)7–8(2):8:8:6:6:6:2T1T2; genital opening of males flanked by 7–8 (rarely 6) setae on each side. Chelicerae (Fig. 361) 1.9–2.1 (♂ ♀) times as long as broad, palm with 6 setae and 1 lateral microseta; fixed finger with 2 distal large teeth followed by 5–8 small teeth proximally reduced in size and few proximal microtubercles; movable finger with an isolated subapical tooth (di), at level with the spinneret, followed by a large tooth and 6–8 teeth proximally reduced in size; gs ratio 0.55–0.61; spinneret largely rounded, weakly prominent in male but more prominent in female (Figs 361–362); rallum with 11 blades; serrulae interior and exterior with 12–14 and 14–16 blades respectively. Coxal setae: pedipalp 5 (including 2 on manducatory process), I 3 + 3 marginal microsetae, II 4, III 5, IV 6; coxa II with 3–9 (mainly 5–6) coxal spines, coxa III with 2–4 (mainly 3) coxal spines; intercoxal tubercle bisetose. Pedipalp: femur 4.2–4.8 (♂ ♀) times as long as broad, femoral chaetotaxy 3:5:2:5:1; chela (Figs 365, 369) 4.9–5.5 (♂) or 4.3–5.0 (♀) times as long as deep; hand of chela 1.85–2.05 (♂) or 1.55–1.95 (♀) times as long as deep, mainly darker than fingers, slightly conical in dorsal view (Figs 363–364); fixed chelal finger with 36–52 (♂) or 31–50 (♀) contiguous teeth, cuspidate and slightly inclined backwards, with the distal side mainly convex, rarely straight, except for the 4–9 proximal teeth that are low and rounded; all teeth with dental canal (Figs 366–368, 370–372); fixed finger at level of est-it with 7–11 (♂) or 6–9 (♀) teeth occupying 0.1 mm, distance between successive apices 0.008 –0.014 (♂) or 0.009 –0.019 (♀) mm; tip of fixed chelal finger with apical sensilla af 1- 2, distal paraxial seta gradually curved and thin; movable chelal finger with 26–38 (♂ ♀) teeth that in the distal half of the finger are similar in shape to those of the fixed finger but have a wider base, in the proximal half of the finger they are rounded and gradually reduced backwards to halfway between sb-b; (between sb and b they are sometimes recognizable only by the presence of dental canal) (Figs 366–368, 370–372); movable finger at level of st-t with 7–10 (♂) or 6–8 (♀) teeth occupying 0.1 mm, distance between successive apices 0.009 –0.015 (♂) or 0.010 –0.018 (♀) mm; coupled sensilla pc at level of sb or just distad of sb; tip of movable chelal finger with apical sensilla am 1- 2; trichobothria as in figs 365, 369; ratio sb -st/sb -b = 1.8–2.0; ratio of movable finger/hand of chela 1.5–1.8 (♂), 1.4–1.85 (♀); ratio of pedipalpal femur/movable finger 1.05–1.2 (♂ ♀); ratio of pedipalpal femur/carapace 1.2–1.35 (♂ ♀).
Measurements (in mm). Body length 1.1–1.5 (♂) or 1.5–1.85 (♀). Carapace 0.36–0.405 × 0.38–0.45 (0.34–0.42 anteriorly) (♂) or 0.42–0.54 × 0.47–0.60 (0.43–0.56 anteriorly) (♀). Chelicerae 0.305–0.39 × 0.155 –0.195 (♂) or 0.39–0.50 × 0.20–0.26 (♀); movable finger length 0.16–0.20 (♂) or 0.205–0.26 (♀). Pedipalp: femur 0.42–0.54 × 0.095–0.12 (♂) or 0.53–0.675 × 0.11–0.15 (♀); chela 0.63–0.81 × 0.10–0.155 (♂) or 0.72–0.98 × 0.15–0.215 (♀); hand length 0.235–0.31 (♂) or 0.26–0.39 (♀); movable finger length 0.395 –0.495 (♂) or 0.44–0.60 (♀).
Description of tritonymph. Integument with weak pigmentation, hispid granulation less marked than in adults. Carapace 0.90 times longer than broad, form of anterior margin and eyes as in adults; chaetotaxy 4:6:4:2:2(18), length of anteromedian macrosetae 0.08 mm. Chaetotaxy of tergites as in adults. Chaetotaxy of sternites II–IX 5:(2)8(2):(1)6(1):7:6:6:6:6. Chelicerae 1.9 times as long as broad, palm with 5 setae and 1 lateral microseta; fixed finger with 5–7 teeth, proximally reduced in size, and a few proximal microtubercles; movable finger with an isolated subapical tooth (di) and 5–7 teeth; gs ratio 0.57; spinneret prominent and apically rounded as in females. Coxal setae: pedipalp 5 (including 2 on manducatory process), I 3 + 2 marginal microsetae, II 4, III 5, IV 5; coxa II with 3–4 coxal spines, coxa III with 2–3 coxal spines; intercoxal tubercle bisetose. Pedipalp: femur 4.0–4.1 times as long as broad; chela 4.7–4.75 times as long as deep; hand of chela 1.8 times as long as deep; fixed chelal finger with 31–39 contiguous teeth, all with dental canal; movable chelal finger with 25–30 teeth, reduced in size towards finger base, reaching back between st and b; coupled sensilla pc nearer to b than to st; ratio of movable finger/hand of chela 1.55–1.6; ratio of pedipalpal femur/movable finger 1.05; ratio of pedipalpal femur/carapace 1.1.
Measurements (in mm). Body length 1.1–1.2. Carapace 0.31–0.34 × 0.34–0.38 (0.31–0.34 anteriorly). Chelicerae 0.275–0.30 × 0.145–0.16, movable finger length 0.14–0.155. Pedipalp: femur 0.34–0.37 × 0.085–0.09; chela 0.52–0.57 × 0.11–0.12; hand length 0.20–0.22; movable finger length 0.32–0.345.
Remarks. Chthonius pygmaeus was described by Beier (1934) from specimens collected in the Tatra Mountains (Northern Carpathians) of Slovakia and compared with C. jonicus, from which it differs—according to Beier (1934) —in having the chelal teeth evidently triangular (deutlich dreieckigen) and the carapacal chaetotaxy with two setae on the posterior margin (4 setae in C. jonicus).
Subsequently, Beier (1951) described and attributed to this species specimens from Carinthia (Austria), pointing out few differences with type specimens, mainly the fixed chelal finger with 36–38 teeth (28–33 in Slovakian specimens) and coxa II with 5–6 coxal spines (11 in Slovakian specimens). It is however to be noted that the Slovak male’s chela design (Beier 1934: 54, fig. 1) shows both fingers slightly curved, while those of the Carinthian specimen (♀?) (Beier 1951: 165, fig. 1b) has straight fingers. We emphasize that the species should be redescribed from specimens collected at the type locality. At present these are unavailable.
Among the species of the Chthonius ischnocheles group, C. pygmaeus is morphologically similar to the epigean C. guglielmii, known from Veneto to Liguria, and to the epigean C. carinthiacus, known from Friuli to Trentino. It differs from C. guglielmii in the following characters: chelal teeth acuminate, cuspidate and slightly reclined, mainly with convex distal side (Figs 365–372) [chelal teeth low, cuspidate and slightly reclined, with sinuous distal side (Figs 150–157) in C. guglielmii], fixed and movable chelal fingers (♂ ♀) with 31–52 and 26–38 teeth respectively (with 49–61 and 37–49 teeth, respectively, in C. guglielmii), palpal hand brown, mainly darker than fingers, and slightly conical in dorsal view (Figs 363–364) [no darker than fingers and short ovoid in dorsal view (Figs 148–149) in C. guglielmii].
Chthonius pygmaeus differs from C. carinthiacus in the following characters: epistome prominent (epistome broadly rounded, not prominent in C. carinthiacus); chelal fingers with contiguous, slightly reclined teeth with convex distal sides (Figs 365–272) [with large, sharp, reclined and widely spaced teeth with sinuous distal sides (Figs 67–76) in C. carinthiacus]; fixed and movable chelal fingers (♂ ♀) at level of est -ist and st -t with 6–11 and 6–10 teeth occupying 0.1 mm respectively, distance between successive apices 0.008 –0.019 and 0.009 –0.018 mm respectively (both fingers with 4–7 teeth occupying 0.1 mm, distance between successive apices 0.014 –0.032 and 0.014 –0.028 mm, respectively, in C. carinthiacus).
description: Published as part of Gardini, Giulio, 2021, The Italian species of the Chthonius ischnocheles group (Arachnida, Pseudoscorpiones, Chthoniidae), with reference to neighbouring countries, pp. 1-131 in Zootaxa 4987 (1) on pages 111-115, DOI: 10.11646/zootaxa.4987.1.1, http://zenodo.org/record/4979653