FENIAN MOBILIZATION AT MALONE AND ELSEWHERE--GEN.

MEADE'S PROMPT ACTION STOPS THE INVASION--ARREST OF GEN.

SWEENY AND STAFF.
The principal points of rendezvous for the Fenians who were intended to operate on the St.Lawrence frontier were Ogdensburg, Watertown, Malone and Potsdam, in the State of New York, and at these places large bodies of men began concentrating during the first two or three days in June.
General Sweeny was in personal command of the troops of the Irish Republican Army in that department, and had made every arrangement to invade Canada along that line, in accordance with his original plan of campaign.

He made his headquarters at Ogdensburg for a time, and from there directed the mobilization of his columns for the contemplated attacks on Prescott, Cornwall and other points on the Canadian border.
Meanwhile Gen.

Michael J.Heffernan, Gen.