The eastern dome arch is prolonged into a barrel-vaulted bema, flanked by shallow niches leading to the prothesis and diaconicon, and beyond the bema is the semicircular apse. Only the diaconicon now remains, covered by a cross-groined vault, and its apse pierced by a door leading to the hall of the Teké. The place of the prothesis has been taken by a similar door and a small Turkish dome. The western dome arch is filled in with a triple arcade resting on two marble columns with finely carved cubical capitals. Above the arcade is a group of three windows whose heads are circular on the inside, but pointed on the outside. To the west of this arcade is an oblong passage corresponding to the 'inner narthex' of S. Theodosia. It is in three bays. The central long bay is barrel-vaulted; the two outer bays open into the north and south 'aisles'; the bay to the north is covered by a Turkish dome, while that to the south has a cross-groined vault which seems to be original. Beyond this to the west is the outer narthex, a fine piece of work, and, from the character of its details, of the same period as the western dome arcade. It is in five bays. The three central bays correspond to the 'inner narthex'; the middle bay is covered by a low saucer dome on pendentives, and is separated from the two side bays by columns set against flat pilasters. The latter bays are covered by groined vaults springing from the imposts of the capitals, which are of the Byzantine Ionic type, with high carved imposts. They resemble the capitals in the gallery of SS. Sergius and Bacchus, and are worthy of particular notice. [Illustration: PLATE XXVIII. (1) S. ANDREW IN KRISEI. OUTER NARTHEX. (2) S. ANDREW IN KRISEI. INNER NARTHEX, LOOKING SOUTH. _To face page 114._] The two outer bays are separated from the central compartment of three bays by strongly projecting pilasters. They are covered by low saucer domes similar to the dome over the central bay, and communicate on the east with the 'aisles.' Both outer and inner narthexes are in one story, above which rise the windows of the western dome arch and the semi-domes on north and south. Turning now to the exterior, the south wall is the only outer wall which is exposed at the ground level. It is faced with finely dressed and polished stone, with thin joints, no tiles, and a stone-moulded cornice. The windows are covered with four centred Turkish arches and are evident insertions. Above the stone cornice rise the low drums of the semi-domes. These, as well as the square base of the dome and the dome itself, are faced with polished stone alternating with courses of three bricks set in thick beds of mortar. The angles are plain, without shafts, and the drums, dome base, and dome are crowned with stone cornices moulded to a reversed ogee.