...er the command of Commodore Porter, arrived at Fortress Monroe, Va., having left the south-west pass of the Mississippi on the seventeenth of the month.--The rebel steamer Memphis was captured by the United States gunboat Magnolia, she having run the blockade of Charleston, S. C., on the night of the twenty-seventh.--Simeon Draper, of New York, was appointed by the War Department a Special Commissioner to supe...