Geneaphantom

Genea-phantom – those people in your tree who you know existed, family history has always treated as a given, but when you go looking, you cannot find a shred of evidence they ever existed.  Also known as Census-dodgers.

Source: http://indianadillmans.blogspot.com/2011/03/saturday-night-genealogy-fun.html#ixzz3BmeoCBYQ