My desire is to delete the folder(s).  I have various pieces of content from various sources, and my plan was to migrate them from individual company names to groups, like clothes, sci-fi, animals, etc.

I've managed to migrate content, but they weren't in explicit sub-directories, even though the Poser library pallette seemed to have them that way.  Now that the pallette directories are empty, I can't find anything to remove to make those directories go away in the pallette. 

In an ideal situation, the library pallette would just allow you to move/delete files and folders just like any file manager.  Maybe this should be a feature request....