I have loaded through Font Book a whole font collection. After this Font Book stopped working so I got rid of the fonts and the files that keep track of them in Font Book. Now Font Book works correctly and the fonts in that particular collection don't appear. The problem is that they still appear available in inDesign, Illustrator and Photoshop, making my font menu extremely long and slowing down the application!.
These fonts don't appear in other non-Adobe applications. I have done a search for the font files and they are nowhere!
Many thanks for your views and advice!