Two men began to fight on the first floor of the WhitehallFerry terminal at 10:30 a.m. Mon. Oct. 6 and one of them fled onto a Staten Island-bound ferry with five dollars he had taken from his adversary, police said. The suspect, Ernesto DeJesus, 41, of 35 Holland Ave., Staten Island, was arrested when the ferry landed at the Staten Island terminal and was charged with robbery, police said. The victim was taken to Bellevue Hospital in stable condition with lacerations of the scalp.