On the march to this ground, a skirmish ensued with a small party of the enemy posted to defend a narrow causeway, who were pursued for a mile, when a considerable body appearing in front, behind stone walls and in woods, some companies of light infantry and a part of the chasseurs were detached to dislodge them, which they did effectually; Lieutenant-Colonel Musgrave commanding the first battalion of light infantry, and Captain Evelyn of the Fourth regiment, were both wounded; the latter is since dead, and much to be regretted as a gallant officer; but Lieutenant-Colonel Musgrave is in a fair way of recovery; three soldiers were killed and twenty wounded; the enemy's loss upon this occasion was a Lieutenant-Colonel killed, a Major wounded, and about ninety men killed and wounded.[1] The part of the Sixteenth Light Dragoons that arrived with Lieutenant-Colonel Harcourt on the third instant (one transport being still missing) and the whole of the Seventeenth Light Dragoons, joined the army on the 20th. On the 21st the right and centre of the army moved to a position about two miles to the northward of Rochelle, on the road to the White Plains, leaving Lieutenant-General Heister, with two brigades of Hessians and one of British, to occupy the former ground. Lieutenant-Colonel Rogers,[2] with his corps of Rangers was detached to take possession of Mamaroneck, where the carelessness of his centries exposed him to a surprize from a large body of the enemy, by which he lost a few men killed or taken; nevertheless, by a spirited exertion he obliged them to retreat, leaving behind them some prisoners and several killed and wounded. The sixth brigade, commanded by Brigadier Agnew, was moved the 22d to sustain the post of Mamaroneck. On the same day Lieutenant-General Knyphausen, with the second division of Hessians and regiment of Waldeckers, having arrived the 18th at New York, landed at Rochelle, was ordered to remain there to cover the disembarkation of the stores and provisions. Upon the movement of the army to Frog's Neck the enemy detached a corps to White Plains, and quitted their position about King's Bridge with some precipitation, leaving two thousand men for the defence of Fort Washington, extending their force behind the Bronx, from Valentine's Hill to White Plains, in detached camps every where entrenched. Their left by this means covering an upper communication with Connecticut, as well as the road along the North River, it was judged expedient to move to White Plains and endeavour to bring them to action.