Erigone cristatopalpus Simon, 1884

(Figs 1–6)

Material: Eastern Giant Mts. by the peak called Smogornia (PL)/ Stříbrný hřbet (CZ), 50°44'54"N, 15°41'20"E, 1410 m a.s.l., pitfall traps, 2 males, 11–31 May 2011 and 11–31 May 2012; a transborder subalpine mire with a mosaic of habitats, i.e. raised and transition parts and dwarf mountain pine .

Distribution: It is a very rare spider species, which distribution in the Central Europe is restricted to the highest mountain ranges, i.e. the Alps (Simon 1884, Thaler 1978, Muster & Hänggi 2009, Tanasevitch 2011) and Slovakian part of the Tatra Mountains (Miller 1971, Svatoň & Kovalčík 2006). The species has been found in Austria, France, Germany, Italy, Lichtenstein, Slovakia, Switzerland (van Helsdingen 2016). Lately, it was also reported in the Czech Republic, from the Hrubý Jeseník (Růžička 2016). E. cristatopalpus is also known in other parts of the Palaearctic (mountains of South Siberia, East Siberia, Russian Far East) and in the Nearctic (Tanasevitch 2011, 2013).

Remarks: There used to be numerous taxonomical ambiguities within the Erigone psychrophila -group (to which the presented species belongs; Crosby & Bishop 1928) and many old records might have been just a mistake (Muster & Hänggi 2009, Tanasevitch 2011). The male of E. cristatopalpus has a very distinctive, large mesial and posterior tooth in the embolic division of the palp (Figs 1, 3, 6) and small but clear dorsal apophysis on the palpal tibia, next to the very noticeable tibial pit (Figs 1, 2, 6).

Both of the collected E. cristatopalpus specimens have the cheliceral dentition as depicted in the Fig. 4, i.e. six anteriolateral teeth in total, the two terminal – very small, the four in between – conspicuous. This number may vary between four and six and it is variable within the species (Muster & Hänggi 2009, Tanasevitch 2011). The two specimens were caught in the subalpine peat bog. This fact stays in accordance with the previous information that this species has a strong affinity to wet habitats (Muster & Hänggi 2009).