Still at large.
--The convict, Bill McDonald, who escaped from the penitentiary on Wednesday last, was still at large yesterday evening. From a description of the prisoner furnished the city police, we learn that he was born in New Orleans, is five feet six inches high, dark hair, (what he has left,) sallow complexion, dark eyes, and Roman nose. The left elbow of prisoner has been broken, and he has on one arm the figure of a fireman, done in India ink.