Is mentioned and depicted here in a German article by Brauckmann et al. (1997) about rare arthropod fossils from the German Lower Carboniferous:

http://www.ap-h.de/download/1997_3.pdf

So you could ask Carsten Brauckmann from Clausthal-Zellerfeld:

http://www.geologie.tu-clausthal.de/abteilungen/palaeontologie/mitarbeiter/

or, because original describer August Goldfuss was primarily working in Bonn, you could address the working group of Jes Rust/ Bonn University and ask them about the holotype specimen:

https://www.researchgate.net/profile/Jes_Rust/