As part of the fossil lot from the Skaly beds, that I purchased on E-bay, there were some Crinoid stem sections. Upon closer examination of some of the pieces I noticed evidence of Epibont attachments. The first three specimens appear to be Crinoid hold fasts or Bryozoan attachment bases.
Specimen #4 - This specimen has some "dimples" in it which might be the trace of a boring sponge.
Specimen #5 - This one is noteworthy because it has two epibonts - A Bryozoan and a possible Crinoid holdfast.
All the above specimens come from the Skaly beds (Devonian, Eifelian to Givetian stages) near Kielce, Poland.