The highest story contains the large single windows which light the cross arm and the gynecaeum, the former flanked by two semicircular niches, the latter by two brick roundels with radiating joints. Between them, above the west angle compartment window, is a flat niche with a Turkish arch. It is possible that there was originally a break here extending to the cornice, and that this was filled up during Turkish repairs. The cornice has two ranges of brick dentils and is arched over the two large windows. The domes on the building have flat angle pilasters supporting an arched cornice. The masonry is in stripes of brick and stone courses, with radiating joints to the arched niches and a zigzag pattern in the spandrils of the first-story arches. At this level are four carved stone corbels with notches on the upper side, evidently to take a wooden beam. These must have supported the roof of an external wood cloister. The inscribed string-course already mentioned between the ground and first stories bears a long epitaph in honour of Michael Glabas Tarchaniotes.[248] (Fig. 49.) The three apses at the east end are of equal height. The side ones are much worn but were apparently plain. The centre apse is in three stories with alternately flat and circular niches in each side. It is crowned by a machicolated cornice similar to that on the east end of S. Theodosia. The general composition, as will be seen from the description, arises very directly from the internal arrangements of the chapel and is extremely satisfactory. The ranges of arches, varying in a manner at first irregular, but presently seen to be perfectly symmetrical, give a rhythmic swing to the design. The walls are now heavily plastered and the effect of the horizontal bands of brick and stone is lost; but even in its present state the building is a very delightful example of Byzantine external architecture. Evidently the foundress of the chapel wished the monument she reared to her husband's memory to be as beautiful both within and without as the taste and skill of the times could make it. [Illustration: PLATE XLII. S. MARY PAMMAKARISTOS. SOUTH SIDE OF THE PARECCLESION. _To face page 156._]