MoIlxain's Hotel, 14 . miles west of HcConnbllsburg, June 25.—The rebels in force entered MeConellsburg last night at 8 o’clock. The telegraph operator after a six hours journey through tho mountain8,reaehed this place and established an office. The rebel advance was met by the 12th Pennsylvania cavalry, and a brisk skirmish ensued. The 12th was finally compelled to retreat be fore the superior numbers, with a loss of three wounded.. A regiment of militia, under Col. Seink fell baca kfc the advance of the enemy, but anindependent company; under Capt. Wallace, took ita position in the mountains, bushwhacking tbe.reb.els with great success* Numbers of rebels are known to have been, killed,imt the extent of their loss is nnksowa* WV