The Basilican church of the period has been so often described that it will not be necessary to give a detailed description of it. It generally consisted of a nave, with two aisles separated from the nave by arcades; at one end (sometimes at both) the building terminated in an apse, of which the floor was raised; this raised floor in later times projected into the nave and was protected by a railing.[110] The altar was in the centre of the string of the arc of the apse, and round the arc were seats for the clergy, the bishop's throne being in the centre, in the place which would be occupied in a Roman heathen Basilica by the presiding magistrate. Beneath the raised floor of the apse was the _confessio_ or crypt, in which the body or relics of the saint to whom the church was dedicated were deposited. Plans of several Saxon crypts still remaining in England will be found in Mr. Micklethwaite's valuable paper in the _Archæological Journal_, New Series, vol. iii. No. 4. At a little later period a further change was made; on the floor of the nave from the chancel westward a space was divided off by a low screen, in each side of which was a _bema_ or pulpit; from which the Gospel and Epistle were read, and the services sung by the Canonical singers.[111] A very complete screen of a little earlier date than St. Augustine may still be seen in the church of San Clemente, Rome; the ancient church from which it was removed is underneath the present church; westward of the church was the atrium, an open court surrounded by a colonnade; the atrium seems to have been used in some British churches for the canons, who had cells round it. [Illustration: S. CLEMENTE, ROME. INTERIOR SHOWING ANCIENT SCREEN. _To face page 146._] St. Cadoc early in the sixth century built a church in Lancarvan monastery, which monastery he rebuilt; each of the thirty-six canons had a residence _in atrio_,[112] the residence being probably a cell with a door opening into the atrium, such as may still be observed in some old monastic cloisters on the Continent. There is evidence of an atrium at the west end of Brixworth church, and the construction of the basements of the towers at St. Mary, Deerhurst, at Monkswearmouth, and Barton-on-Humber, seems to show that there was a similar construction at the west end of those churches. The church of S. Ambrogio, Milan, possesses an atrium built by the Comacines, but it is of much later date, and would therefore afford a general idea of an early Saxon church atrium only in plan.