De Morgan's excavations encompassed two groups of mastabas: The group of mastabas of the era of Snefru, situated near the pyramid of Usertesen III consists of monuments built of stone, while further south, near the tomb of Amenemhat II, we find only the mastabas of brick. (p. 2). No. 24 was one of the second group.Mastaba 24
From the entrance a narrow corridor leads to the main hall which contains two stelae. Three shafts are behind the stelae. To the west of this is another construction attached to the first. It contains a shaft and three rooms, including two (S and S') that are almost certainly serdabs.
de Morgan 1903, fig. 43
De Morgan Fouilles a Dahchour, 1894-95, 1903 pp. 18-21