Yes - looking at it from my Mac, it is marked as invisible. It contains infocache as well as the (empty) index subdirectory.In the phone's own file manager, it is invisible.
Just now I've downloaded the dictionaries direct to my phone from skydrive.live.com (I couldn't download from the lingoes server choice which is why I used my Mac). I copied them to the GoldenDict directory and they work - good! I'd like to delete the dictionaries which didn't work. I see that I have, for example, English-French Dictionary.ld2 and English-French_Dictionary.ld2. Which ones should I delete? With or without underscore?