The architects of Ptolemaic times changed certain details of arrangement.

They erected chapels and oratories on the terraced roofs, and reserved space for the construction of secret passages and crypts in the thickness of the walls, wherein to hide the treasure of the god (fig.

81).

They, however, introduced only two important modifications of the original plan.

The sanctuary was formerly entered by two opposite doors; they left but one.
Also the colonnade, which was originally continued round the upper end of the court, or, where there was no court, along the facade of the temple, became now the pronaos, so forming an additional chamber.