Upon these arches is raised what has been called an elliptical dome. But in no part has it the character of a true ellipse, nor does it spring from its supporting arches in the simple regular manner of a dome, but in the complex manner of a vault built upon arches of unequal curvature. It should therefore rather be called a domical vault. Where it shows above the roof it has the appearance of a modified and very low cone covering an irregular elliptical drum. The eastern bay of the nave is square on plan, bounded by semicircular arches, all extended so as to form short barrel vaults. The western arch is joined to the eastern arch of the western bay, thus forming a short barrel vault common to both bays. The vault to the east runs to the semi-dome of the apse; whilst the vaults to north and south, like the corresponding vaults in the western bay, extend to the outer walls and cover the eastern portions of the aisles and galleries. Above the supporting arches regular pendentives are formed, and above these there is a drum carrying a dome. The apse to the east of the nave is semicircular within and covered by a semi-dome. Between that semi-dome and the eastern barrel vault of the nave a break is interposed, giving the bema arch two orders or faces, with their external and internal angles rounded off, and the whole surface of the semi-dome and of the bema arch is covered with mosaic. At one time the mosaic extended also over the surface of the barrel vault. The decoration in the semi-dome consists of a large cross in black outline upon a gold ground; below the cross there are three steps set upon a double band of green that runs round the base of the semi-dome. A geometrical border bounds the semi-dome, and then comes the following inscription, an extract from Psalm lxv. verses 5, 6 (the lxiv. in the Septuagint version), on the inner face of the arch: [Greek: (DEUT EI)SOMETHA EN TOIS AGATHOIS TOU OIKOU SOU, HAGIOS O NAOS SOU THAUMASTOS EN DIKAIOSYNÊ EPAKOUSON HÊMÔN O TH[EO]S O S[ÔT]ÊR HÊMÔN HÊ ELPIS PANTÔN TÔN PERATÔN TÊS GÊS KAI TÔN EN THALASSÊ MAK(RA)[N]]. (Come we will go?) in the good things of thy house. Holy is thy temple. Thou art wonderful in righteousness. Hear us, O God our Saviour; the hope of all the ends of the earth and of them who are afar off upon the sea. The letters enclosed within curved brackets and the accents[141] above them are paint only; the letters within square brackets are not in the inscription, but are supplied where evident contractions render that course necessary. The remaining letters are in unrestored mosaic. Probably [Greek:(Deut ei) sometha] is a mistake of the restorer for the word [Greek: plêsthêsometha] in the original text. 'We shall be filled with the goodness (or the good things) of thy house.' Three other geometrical patterns in mosaic succeed, after which follows a broad wreath of foliage on the outer face of the bema arch and the words: