The enemy dashed rapidly up the canal, driving in the patrols, and attacked Captain Deane's company, I, Sixth Michigan Cavalry, on duty at Seneca locks. Captain Deane fell back toward Poolesville, forming line three times, and only retreating when nearly surrounded. The enemy followed to within 3 miles of Poolesville, when he rapidly retired, destroying the camp of Captain Deane, and recrossing the river at the point where he had crossed. Our loss is 4 men killed, 1 man wounded, and 16 men missing. The men above reported "missing" are men who were absent from Captain Deane's camp, doing patrol duty along the canal, along a line extending to Muddy Branch, more than 13 miles from my headquarters, and were not reported by me in my telegraphic dispatches because they were not then considered to be properly "missing, " in the absence of any information to that effect. The enemy left killed on the field their commanding officer, Captain [W. G.] Brawner, and his second lieutenant. A statement of our loss in detail is inclosed.

Very respectfully, your obedient servant,

A. B. JEWETT,

Colonel, Commanding Brigade.

Lieutenant Colonel J. H. TAYLOR, Chief of Staff.

Numbers 2. Report of Major John S. Mosby, Virginia Patrisan Rangers.

MIDDLEBURG, VA., June 10, 1863.

GENERAL: I left our point of rendezvous yesterday for the purpose of making a night attack on two cavalry companies of the enemy on the Maryland shore. Had I succeeded in crossing the river at night, as I expected, I would have had no difficulty in capturing them; but, unfortunately, my guide mistook the road, and, instead of crossing by 11 o'clock at night, I did not gen over until after daylight. The enemy (between 80 and 100 strong), being apprised of my movement, were formed to receive me. A charge was ordered, the shock of which the enemy could not resist, and they were driven several miles in confusion with the loss of 7 killed, a considerable number wounded, and 17 prisoners; also 20 odd horses or more. We burned their tents, stores, camp equipage, &c. I regret the loss of 2 brave officers killed - Captain Brawner and Lieutenant [George H.] Whitescarver. I also had 1 man wounded. Respectfully, your obedient servant,

JNO. S. MOSBY,

Major of Partisan Rangers.

J. E. B. STUART.

Major-General.