Here's a link (via Amy Crehore's always delightful blog Little Hokum Rag) to a collection of hand-colored vintage postcards of performers from the Casino de Paris.  These ladies were the forerunners of the Vegas showgirl by a line of direct transmission -- the legendary topless revues in Vegas were staged by artists who'd worked at places like the Casino de Paris.
  Donn Arden, for example, who created Jubilee! more than twenty years ago, once worked for the Cafe Lido in Paris, home of the famous Bluebell girls and one of the classic French topless revues.  Jubilee! is one of the two traditional showgirl revues still surviving on the Vegas Strip.