...boat De Soto.--The National cavalry, under General Milroy, had a skirmish with the rebels, at a point six miles from Winchester, Va., in which they killed six and captured seven prisoners.--Richmond, Clay County, Mo. , was captured, together with the National force occupying it, by a band of rebel guerrillas, after a severe fight, in which two officers of the Twenty-fifth Missouri regiment were killed. A lieuten...