San Pietro, however, has one very great peculiarity. It has no façade, but is built with the usual Lombard three apses at one end, and a single semi-circular tribune at the other. The only door is at the side. The priest, who is naturally proud of his church, and learned in its history, told us that by this peculiar form the builders wished to represent a ship, and pointing out the great square pilasters that break the line of columns at the fourth arch from the west, he showed how the raised poop of a vessel was expressed by the greater height and width of the four arches at the west end. Certainly the narrowing effect being towards the chancel instead of the reverse, is most remarkable. I was not, however, convinced by his symbolism, and realizing the greater proportions of the west end, where three arches with fluted columns stretched across a tribune, now turned into an organ-loft, I felt convinced that the present form was not the original. Either the ancient altar once stood at the west end, and the church, like so many Lombard ones, had formerly faced the opposite way; or else the semi-circular tribune, which seems to be of later work, has been added by restorers, to cover in the three arches of the ancient façade. That, in fact, the large solid pilasters in the nave marked the ancient wall of the interior, and the four arches on the other side of them formed the narthex. To support the first theory, is the fact that the altar called St. Peter's altar stands now isolated in that west end, and the canopy in the form of an ancient Lombard _ciborium_ stands on four columns above it, carved in stone in very early style. The opposite theory of the narthex having been at that end, may on its side be confirmed by one of the frescoes, the last but two on the south wall, which represents the church itself as it was prior to A.D. 1000. Here the artist has, with a curious mediæval disregard of perspective and possibility, represented both ends of the church in one view, and here we see plainly the three apses with their marble perpendicular ribs on one side, and the façade of large arches with a row of smaller ones across the building above them on the other. I leave the question of this puzzling west tribune to wiser judges than myself, and trust that some new Fergusson, Hope, or Street may some day discover the truth.