rosette of the side niches is omitted. Rooms 31 and 32 are 10·05 metres from east to west and 4·90 metres from north to south. Room 41, lying opposite to room 32, has an equal length and the same system of doors, but no decoration. Room 42, which corresponds with room 31, is only 7·25 metres from east to west, since space had to be allowed for the two stairs leading out of the central court, one to the roof and one to the underground chamber. In the south-east corner of No. 42 there is a small door giving access to a narrow passage behind the block of masonry which contains the upper stair. It turns at right angles into a short passage lying above the lower stair. The vaulted underground chamber corresponds in length and width with No. 42 (section _e-f_, Plate 5, Fig. 1). It is lighted by three small windows which are splayed upwards to the ground-level--one of these can be seen in Fig. 3 of Plate 29. The room was filled with débris, so that I cannot be certain of its height. In the west wall there is an arched niche or ṭâqchah. In the intense heat of southern Mesopotamia it is customary to provide all houses with underground chambers, wherein the inhabitants spend the greater part of their day in summer. They are known as serdâbs. To the authors of _Ocheïdir_ I am indebted for an interesting observation with regard to the vault of No. 41.[26] It was built in sections over a movable centering which has left its mark upon the concrete of which the vault was formed. Rooms 32 and 41 communicated by doors in the south wall with the columned chambers 33 and 40 (Plate 31, Fig. 2), which are exactly alike in every respect, except that No. 40 is connected by a door with the room to the south, No. 39, whereas there is no south door in No. 32. Both 33 and 40 have doors, covered with ovoid arches set back from the jambs, leading into the corridor 28, and both are divided into three aisles by two arcades of three arches carried on two masonry columns. The aisles run north and south. The innermost aisle in either case forms part of the vaulted corridor, 36, which runs round three sides of No. 30. This aisle is only 2·50 metres wide, as compared with the 2·85 metres of the other two aisles. All the aisles are roofed with barrel vaults. Though the columns are of stone masonry, the capitals, together with the arches and walls they carry, and the segmental vaults, are of brick. The columns are separated from one another from north to south by a distance of 2·50 metres, but the distance between each column and the wall behind it is only ·90 metre; hence the wide central arches rise almost to the spring of the vault, whereas the side arches are from their narrow span necessarily much lower (Plate 32, Fig. 1). The curve of all the arches is a pointed ovoid, and the narrow arches are considerably stilted. These last are built of concentric rings of small brick tiles, the inner band laid vertically, the outer horizontally. The