ibooks won't accept files

Hi , i just got a new mac as the other was getting old,i assumed i would be able to transfer epub books via time machine to ibooks,i have tried several methods to no avail.I can see them in finder as encoded books (no titles on display) and they even have the ibooks icon at the side of them,but i cant seem to add them and see them in ibooks.Pdf's have been easily t/f and i can open and see them.I have tried dragging them to itunes and it seemed to be accepting them ,but they dont appear in ibooks.I also tried "add new books/files "and selected the encoded files,but again nothing........

Any ideas please?

Thanks

Aaron