four boxes at
the angles of the cross, while in S. Mary Pammakaristos and SS. Peter
and Mark it is absent (pp. 149, 193). But though no longer a structural
part of the church, a gynecaeum appears over the narthex in the latest
type of church (p. 215). It is generally vaulted in three bays,
corresponding to the three bays of the narthex below, and opens by three
arches into the centre cross arm of the church and into the aisles.

_The Narthex._--Unlike the gynecaeum, the narthex tends in later times
to become of greater importance, and to add a narthex was a favourite
method of increasing the size of a church. In basilican churches, like
S. John of the Studion, the narthex was a long hall in three bays
annexed to the west side of the building, and formed the east side of
the atrium. In domed cross churches with galleries the passage under the
western gallery was used as a narthex, being cut off from the central
area by the screen arcade which supported the gallery. Such a narthex
has been styled a 'structural narthex,' as forming an essential part of
the central building. It occurs in several of the churches of the city
(p. 114).

In domed cross churches without galleries, and in churches of the 'four
column' type, neither narthex nor gallery was possible within the cross,
and accordingly the narthex was added to the west end. It is usually in
three bays and opens into the aisles and central area. Frequently the
ends of the narthex terminate in shallow niches (p. 198). In many
churches a second narthex was added (p. 166) to the first, sometimes
projecting an additional bay at each end, and communicating with halls
or chapels on the north or south, or on both sides of the church (p.
128). S. Mark's at Venice presents a fine example of such an extension
of the narthex.

When a church could not be sufficiently enlarged by additional
narthexes, a second church was built alongside the first, and both
churches were joined by a narthex which extended along the front of the
two buildings. S. Mary Panachrantos (p. 128) is a good example of how a
church could be thus enlarged from a simple square building into a maze
of passages and domes.

_The Interior._--The natural division, in height, of an early church,
whether basilican or domical, was into three stories--the ground level,
the gallery level, and the clearstory or vault level. In the West these
structural divisions were developed into the triple composition of
nave-arc