A filemaker file saves a copy of itself at the very beginning and then your changes are automatically saved throughout. It's possible this file was saved to an unexpected location.
If you launch filemaker, can you find it in the Open Recent list? Can you open it from there?
Have you tried using a filesearch utility to search your hard drive for this file by name?
Note for the future: I and many other developers frequently back up our work through out a development session by choosing save as... copy from the file menu.
Thanks Phil for the help. I finally found it in the Time Machine and restored. Weird thing is not only the Catalogue Raisonne Data Base disappeared but so did the Mailing List Data Base from the desktop too. All is back now and thankful it was not lost.