An autopsy will be performed today on the body of a man discovered in the Mississippi River. People at the Green Gables Marina on Canal Shore Drive in LeClaire saw the body floating about 50 feet from shore and notified authorities a little before noon on Friday. No positive identification has been made, but the body is believed to be that of Brian Hylton of Riverdale. Hylton, who was in his 20s, was last seen September 11th leaving the area of his houseboat on Canal Shore Drive.