l ye
who labour and are heavy laden.'[538] In the corresponding frame to the
south is the figure of the Virgin, and, above it, an arch of overhanging
acanthus leaves enclosed within a square frame with half figures of
angels in the spandrils. The arch encloses a medallion bust, the head of
which is defaced, but which represented the Saviour, as is proved by the
indication of a cross on the aureola. The spaces at the sides of the
medallion are filled in with a pierced scroll showing a dark slab of
porphyry behind it, making a very beautiful arrangement. These frames
are distant from the eikonostasis, which stretched across the front of
the bema arch, nearer to the apse. On the south side are two doors
leading to the parecclesion, and on the north side above the cornice is
a small window from the north gallery.

The dome rests on a ribbed drum of sixteen concave segments, and is
pierced by eight windows corresponding to the octagonal form of the
exterior. The original crown has fallen and been replaced by the present
plain Turkish dome. The prothesis and the diaconicon are represented by
chapels to north and south of the apse. As already stated, they do not
now communicate with the bema, although the position of the old passages
between them and the bema is marked by niches in the marble revetment.
From the fact that the Byzantine marble work is continued across these
passages it is evident that the chapels were cut off from the apse in
Byzantine days. The north chapel is covered by a drum dome of eight
concave sections, and is entered from the lower story of the gallery on
the north side of the church. It should be noticed that the chapel is
not placed axially to this gallery. The south chapel is covered by a
plain drum dome, and is now entered from the parecclesion, evidently as
the result of the alterations made when the parecclesion was added.

The exterior is very simply treated. The side apses show three sides of
an octagon. The central apse has five sides of a very flat polygon, and
is decorated with hollow niches on each side of a large triple window.
It was at one time supported by a large double flying buttress, but the
lower arch has fallen in. As the buttress does not bond with the wall it
was evidently a later addition.

The inner narthex is entered from the outer narthex by a door to the
west. It is with its resplendent marble revetment and brilliant mosaics
a singularly perfect and beautiful piece of work