TWENTY-FIFTH ARMY CORPS.

[January.]-Since last return the following changes have been made in the organization of the corps: The number of the First Division is now Third, and the Third changed to the First Division, by virtue of General Orders, Numbers 8, from headquarters, dated December 31, 1864. The Forty-first U. S. Colored Troops taken from Second Brigade, First Division, and placed in First Brigade, Second Division; the One hundred and seventeenth U. S. Colored Troops taken from First Brigade, Second Division, and placed in Second Brigade, First Division, by virtue of General Orders, Numbers 2, from these headquarters, dated January 2, 1865. The One hundred and fifteen U. S. Colored Troops has been added to the corps, according to instructions from department headquarters, and assigned to the Second Division. During the month Brigadier General C. A. Heckman has been in command, Major-General Weitzel being absent with leave. A portion of the Third Division, commanded by Brigadier General C. J. Paine, forms a part of the expeditionary force that sailed from Fort Monroe, Va., January 6, under command of Brevet Major-General Terry. No official report of its operations has as yet been received. The remaining troops of the corps have participated in no general engagements during the month.

January 23 and 24.-The command was got under arms early in the morning, anticipating a move on the part of the enemy. All remained quiet, however, during the 23rd.

January 24.-In the morning the enemy's rams came down the James River. They were fired upon from our batteries, to which briskly replied. In the evening of the same day they were successful in returning.

The Second Division occupies Fort Burnham and a portion of the line in front of Richmond. The left of the line held by this division was severely bombarded, January 24, resulting in four casualties.

[February.]-Nothing worthy of special note has occurred during the month. The corps holds the same line at Chaffin's farm, Va., as per last return. The Third Division remains in the Department of North Carolina. The First and Second Divisions have drilled each day.

[March.]-The corps holds the same position (at Chaffin's farm, Va.) as per last return. No change of special note have occurred except that-

March 27.-The Second Division, commanded by Brigadier Gene. William Birney, moved to re-enforce the Army of the Potomac, near Hatcher's Run.

[April .]-March 27, the Second Division moved to re-enforce the Army of the Potomac. April 17, it rejoined the corps near Petersburg.

April 3.-That portion of the corps (First Division and Artillery Brigade) remaining at Chaffin's farm, Va., moved upon the evacuation of Richmond and took of the city, where it remained until the 13th instant, performing in and around the city the usual guard and fatigue duties.

April 13.-Moved to South Side Railroad, about three miles from Petersburg, and have remained at this station to the end of the month.

[June.]-May 25 to June 17, the corps embarked in ocean transports at City Point as rapidly as transports could be furnished.

June 7.-The headquarters of the corps embarked and proceeded toward Texas; put into Mobile Bay, Ala., to receive orders from the major-general commanding Military Division of the Gulf, and to coal and water, if possible; coal could not be obtained.