Greenland Gap was attacked yesterday afternoon by the advance of Jones' force-200 cavalry and 100 infantry. The fight lasted from 4 p.m. till dark. Our troops yet hold the gap. I fear the enemy will bring his artillery this morning and shell them out.

B. F. KELLEY,

Brigadier-General.

HARPER'S FERRY, VA., April 26, 1863.

Lieutenant-Colonel CHESEBROUGHT,

Baltimore, Md.:"

A telegram just received from New Creek says that the rebels captured most of the company at Greenland Gap, and have gone toward Oakland, by the Moorefield and Alleghany and Northwestern turnpikes. They are about 3,000 strong-all cavalry. The line is not working west of Piedmont; has no doubt been cut by some rebel residing on the line. They cannot operate with cavalry at Rowlesburg. Can do no other damage between Oakland and Rowlesburg, except to burn the Youghiogheny Bridge.

B. F. KELLEY,

Brigadier-General.

HARPER'S FERRY, VA., April 26, 1863-1.30 p.m.

Lieutenant-Colonel CHESEBROUGH,

Assistant Adjutant-General, Baltimore, Md.:

Telegrams just received from Romney and New Creek. Jones had not advanced on either place to-day. Colonel Smith will arrive at New Creek at about 5 p.m. I think the post will then be safe. Nothing from Roberts, Wilkinson, or Mulligan to-day. Jones could not cross his artillery at Moorefield on account of high water. If General Elliott reaches there to-night, I trust he will capture it.

B. F. KELLEY,

Brigadier-General.

BALTIMORE, MD., April 26, 1863.

Brigadier-General KELLEY,

Harper's Ferry:

It will not do to weaken Maryland Heights by any movements your order. Milroy reports Fitzhugh Lee probably at Markham Station, on Manassas Gap Railroad and the Shenandoah, about 2 miles east of the Blue Ridge, with about 2,000 cavalry and two batteries; was 16 miles from Castleman's Ferry and 10 miles from Berry's Ferry. Besides these, a large force of infantry and cavalry, under General Trimble, is understood to be following from Culpeper Court-House, consisting of five brigades, three of them near Orleans, in Fauquier County, and two Winchester. I have ordered another full, good regiment (One hundred and fifty-first New York) from here to Monocacy Bridge, to await orders. They may not move for some hours.

ROBT. C. SCHENCK,

Major-General.

(Copy to General Halleck.)