A rider was shot dead on a New York City bus Monday afternoon, with the gunman then fleeing, cops said. The 41-year-old victim was blasted in the stomach around 2:30 p.m. on a BX36 bus at East Tremont Avenue and White Plains Road in Parkchester in The Bronx, police said. The injured MTA rider was rushed to Jacobi Medical Center, where he succumbed to his injuries, police said. The gunman — who wore a white t-shirt and used a black handgun in the killing — fled south on White Plains Road and had