Monkey Squirrel is not a monkey but is a squirrel. It is NOT a primate but IS a rodent.
The actual name of the squirrel is a Fox Squirrel (I know there are a lot of squirrely commentators on FOX but that is a different story).
Look at the link I provided here about the Big Cypress Fox Squirrel and see if that looks like the critter you saw. They have been mistaken for monkeys many times.
http://www.dickbrewer.org/fox_squirrel.html