Much history is also contained in the carvings of the pulpit and bishop's throne. The altar has a marble canopy over it, which is a magnificent piece of work, but perhaps hardly suitable for its position. The mosaic pavement is remarkably fine. We now pass into the _Choir Aisles_, which have Norman vaulted roofs, and formerly had apsidal ends, but these were removed when Abbots Ashton and Kirton built the _New Building_ or square end to the church, or perhaps earlier, as there are some aumbreys and double piscinæ of the thirteenth century, and also on the south wall some painted shields and a scroll border of the same date. The windows are later insertions as in the nave. Traces of the old entrance to the destroyed Lady Chapel may be seen in the north wall. We have noticed the building of the ambulatory called the New Building from the exterior of excellent Perpendicular work. Perhaps the most striking features of the interior is the fan-tracery of the roof, the curious bosses, the rebuses of the two Abbots Ashton and Kirton, and the monuments. The principal ones in the choir and aisles are a modern memorial stone of Catherine of Arragon (the old tomb was destroyed by the Puritans, of which fragments have been discovered); the tablet in memory of Mary Queen of Scots; Archbishop Magee's marble monument; Sir Humprey Orme's mutilated tomb; several abbots' tombs and tablets to bishops; Late Saxon tombs of two Archbishops of York, and the famous Monks' Stone which popular tradition associates with the massacre of the Peterborough monks by the Danes in 870. Recent investigators have assigned a later date, and attribute it to Norman work, but we are inclined to favour the Saxon theory. We will now visit the _Transepts_, which are of Norman character. Norman fish-scale ornament and cable and saw-tooth mouldings are plentiful. In both north and south transepts there is an eastern aisle separated by pillars and forming several chapels, which are divided off by Perpendicular screens. The Morning Chapel occupies the aisle of the north transept, formerly the Chapels of SS. John and James, and here is preserved two pieces of old Flemish tapestry, and portions of the old nave screen, and ancient tiles. In this transept are some interesting Saxon coffin lids. In the south transept are the Chapels of SS. Oswald and Benedict. In the former the relics were kept. Here Abbot Sutton's heart was buried. The window is modern. A pre-Reformation inscription is carved round the edge of a stone much worn by time. The old chapter-house, now a music-room, is on the west of this transept. It is Late Norman. A Perpendicular doorway has been inserted here instead of the old Norman door.