Calling himself the new shepherd of Maine’s 193,000 Roman Catholics, Bishop Robert P. Deeley says he must get to know the smell of his sheep before being able to serve them well. His remarks came during his homily at the Mass installing him as bishop of the Diocese of Portland. Cardinal Sean P. O’Malley, archbishop of Boston, presided over the service Friday at the Cathedral of the Immaculate Conception in Portland. Deeley, who becomes the Portland Diocese’s 12th bishop, comes from Boston, where he was an auxiliary bishop. In Maine, he will oversee diocesan operations including three hospitals, a dozen schools, 55 parishes, and more than 100 priests.