THE RECRUITING SERGEANTS of Pennsylvania for the old regiments, in Philadelphia, assembled, to the number of nearly one hundred and fifty, yesterday afternoon, and proceeded, with an excellent band, to the Baltimore depot, to receive General McCLELLAN, their gallant commander, who it was expected would have arrived at 5 o'clock. The company was commanded by Sergeant FIX, assisted by Sergeant KELLY, of the Sixty-ninth Regiment, and Sergeant SINEXON [sic] [probably Robert Sinex (D)], of the Ninety-first [sic] Regiment, and presented a very soldierly appearance. General McCLELLAN not arriving, they proceeded to the house of Dr. J.R.B. McCLELLAN, where the band played all the national airs, winding up with "Hail to the Chief."