Chthonius (C.) euganeus Gardini, 1991: 169 Chthonius mingazzinii Callaini, 1991: 265 The Italian species of the Chthonius ischnocheles group (Arachnida, Pseudoscorpiones, Chthoniidae), with reference to neighbouring countries Gardini, Giulio Zootaxa 2021 2021-06-17 4987 1 1 131 V3BL Gardini, 1991 Gardini 1991 [151,582,402,429] Arachnida Chthoniidae Chthonius Animalia Pseudoscorpiones 41 42 Arthropoda species euganeus  ( Figs 117–126, 409)      Chthonius (C.) euganeus Gardini, 1991: 169, figs 1–7.     Chthonius mingazzinii Callaini, 1991: 265, figs Ia–f (n. syn.).     Typelocality: Italy, Veneto, Padua Province, Rovolon, Busa de l’Orso 1398 V/ PD( 45°23’22”N, 11°40’24”E)   Distribution. Italy( Veneto, Romagna).   Diagnosis ( ♂ ♀).An anophthalmic subterranean  Chthoniusthat differs from other species of the  ischnochelesgroup in the following combination of characters: anterior margin of carapace strongly denticulate, with widely prominent epistome, and with 1 preocular microseta on each side; posterior margin of carapace with 2 macrosetae, without lateral microsetae; chelicerae with 2 or 3 lateral microsetae; chela length 0.97–1.10 mm; chela 5.8–6.35 times as long as deep; chelal fingers with contiguous teeth; fixed and movable chelal fingers with 60–84 and 50–59 teeth respectively; ratio of pedipalpal femur/carapace 1.45–1.55.   Type material of  C. euganeusexamined.  ITALY—  Veneto: Padua Prov.— 1 ♂( holotype), 2 ♀( paratypes), Rovolon, Busa de l’Orso 1398 V/ PD,  43 ma.s.l.,  28.V.1983, E. Piva& I. Ferrarileg. ( MSNV).  Other material examined.  ITALY—  Veneto: Padua Prov.— 2 ♀, Rovolon, Busa de l’Orso 1398 V/ PD,  43 ma.s.l.,  28.XII.1991, E. Pivaleg.   Veneto: Vicenza Prov.— 1 ♀, Alonte, near  La Fontana,  45 ma.s.l.,  16.VI.1996, E. Pivaleg.   Description of adults ( ♂ ♀).Weak troglomorphic facies; integument slightly pigmented, carapace, tergites, chelicerae and pedipalps pale reddish brown; weak hispid granulation on lateral surfaces of carapace, on cheliceral palm and on base of fixed chelal finger. Carapace 0.9–1.0 times longer than broad, trapezoidal, constricted posteriorly; anterior margin between median macrosetae with denticles and a broad, rather flat epistome in both sexes ( Figs. 117–118); no eyes or eye-spots; chaetotaxy m 4m:6:4:2:2(20); length of anteromedian macrosetae 0.10–0.12 mm. Chaetotaxy of tergites 4:4:4:4:6:6:6:6:1T2T1:4:1T2T1:0. Chaetotaxy of sternites 10:(3)8–10(3):(2)7–10(2):7– 8:6: 6: 6: 6:2T1T2:0:2; genital opening of male flanked by 6–9 setae. Chelicerae ( Fig. 119) 2.3 ( ♂ ♀) times as long as broad, palm with 6(7) setae and (2)3 lateral microsetae; fixed finger with 2 distal large teeth followed by 8–10 small teeth proximally reduced in size; movable finger with an isolated subapical tooth ( di) at level ( ♂) or just distad ( ♀) of the spinneret, followed by a large tooth and 6–10 teeth proximally reduced in size; gsratio 0.57–0.58; spinneret weakly raised in males, more prominent and rounded in females ( Figs 119–120); rallum with 11 blades; serrulae interior and exterior respectively with 14 and 17–18 blades. Coxal setae: pedipalp 5 (including 2 on manducatory process), I 3 + 3 marginal microsetae, II 4, III (5)6(7), IV 6–7; coxa II with 9–10 coxal spines, coxa III with 4–6 coxal spines; intercoxal tubercle bisetose. Pedipalp: femur 5.8 ( ♂) or 5.7–5.9 ( ♀) times as long as broad, femoral chaetotaxy 3:6:2:6:1; chela ( Figs 122–123) 6.35 ( ♂) or 5.8–6.15 ( ♀) times as long as deep; hand of chela 2.1 ( ♂) or 1.9–2.05 ( ♀) times as long as deep, long ovoid in dorsal view ( Fig. 121); fixed chelal finger with 78–84 ( 60 in ♀from Alonte) contiguous teeth, cuspidate and slightly inclined backwards in the distal half of the finger, apically rounded in the proximal half ( Figs 124–126); all teeth with dental canal; fixed finger at level of est-itwith 10–11 ( 9 in ♀from Alonte) teeth occupying 0.1 mm, distance between successive apices  0.009 –0.010mm( 0.011 in ♀from Alonte); tip of fixed chelal finger with apical sensilla af  1-2, distal paraxial seta gradually curved and thin; movable chelal finger with 50–59 contiguous teeth, reclined and apically pointed in the distal third of the finger, apically rounded and increasingly reduced towards finger base, reaching back to level of b; between sband bteeth mainly recognizable by the presence of dental canal ( Figs 124–126); movable finger at level of st-twith 9–10 teeth occupying 0.1 mm, distance between successive apices  0.010 –0.011mm; coupled sensilla pcat level of sbor just distad of sb; tip of movable chelal finger with apical sensilla am  1-2; trichobothria as in figs 122–123; ratio sb -st/sb -b= 1.3–1.7; ratio of movable finger/hand of chela 2.0 ( ♂) or 1.9–2.1 ( ♀); ratio of pedipalpal femur/movable finger 1.0 ( ♂ ♀); ratio of pedipalpal femur/carapace 1.45–1.55 ( ♂ ♀). Measurements (in mm). Body length 1.55–1.6 ( ♂ ♀). Carapace 0.45 × 0.45 ( ♂) or 0.44–0.47 × 0.47–0.51 ( ♀). Chelicerae 0.455 × 0.20 ( ♂) or 0.47–0.50 × 0.205–0.22 ( ♀); movable finger length 0.23 ( ♂) or 0.24–0.26 ( ♀). Pedipalp: femur 0.70 × 0.12 ( ♂) or 0.66–0.74 × 0.115–0.13 ( ♀); chela 1.02 × 0.16 ( ♂) or 0.97–1.10 × 0.165–0.18 ( ♀); hand length 0.34 ( ♂) or 0.31–0.37 ( ♀); movable finger length 0.68 ( ♂) or 0.65–0.74 ( ♀).   Remarks.  Chthonius mingazziniiwas described by Callaini (1991)from a female collected at Crepaccio, Pietramora near Brisighella (Ravenna Province, Romagna). Crepaccio presumably corresponds to the cave Crepaccio a Ovest di Ca’ Masiera 764 E/ RA. The female holotypeis currently unavailable and presumably lost (Callaini, in litt.: April 7, 2019). Morphological characteristics and measurements of the  Chthonius euganeusfemales examined here almost perfectly match the description and figures of  C. mingazzinii, apart from the number of coxal spines (coxa II 9–10, III 4–6 in  C. euganeusvs. coxa II 6–7, III 2–4 in  C. mingazzinii).  Chthonius mingazzinii Callaini, 1991is therefore proposed as a junior subjective synonym of  Chthonius euganeus Gardini, 1991( n. syn.). Among the species of the  Chthonius ischnochelesgroup,  C. euganeusis morphologically similar to the subterranean  C. herminiifrom which it differs in the following characters: no eyes (anterior eyes with flat lens, posterior eyes absent in  C. herminii); chelicerae with 2 or 3 lateral microsetae (with 1 lateral microseta in  C. herminii); fixed and movable chelal fingers ( ♂ ♀) with 60–84 and 50–59 teeth respectively (55–62 and 48–52 in  C. herminii); fixed and movable chelal fingers ( ♂ ♀) at level of est -istand st -twith 9–11 and 9–10 teeth, respectively, occupying 0.1 mm; distance between successive apices 0.009 –0.011and  0.010 –0.011mmrespectively (with 6–9 and 6–8 teeth occupying 0.1 mm, distance between successive apices 0.011 –0.017and  0.012 –0.016mm, in  C. herminii); ratio of movable finger/hand of chela ( ♂ ♀) 1.9–2.1 ( 2.2–2.4 in  C. herminii). The above description of  Chthonius euganeusgiven here incorporates the previous one by Gardini (1991). 3323445952 [151,1384,608,635] V, PD de l'Orso Italy 45.389446 Busa de l'Orso 19 11.673334 Padua Province 41 42 1 Veneto holotype 3323445405 1983-05-28 V, PD, MSNV E. Piva & I. Ferrari Italy Padua Prov. 43 Busa de l'Orso Rovolon 41 42 3 2 1 Veneto holotype 3323445903 1991-12-28 V, PD de l'Orso & E. Piva Italy Padua Prov. 43 Busa de l'Orso Rovolon 41 42 2 2 Veneto 3323445622 1996-06-16 La Fontana & E. Piva Italy Vicenza Prov. 45 La Fontana Alonte 41 42 1 1 Veneto