In this, which may be called the level part of the necropolis, the tombs have left but slight and ill-defined traces. Their superstructures have almost entirely disappeared, and yet some which have now completely vanished were seen by travellers to Thebes in the first half of the present century. By comparing what they tell us with the figured representations in bas-relief and manuscript, we may form some idea of the aspect which this part of the cemetery must formerly have presented. The tombs which it contained were built upon the same principles as those of Abydos; a square or rectangular structure with slightly sloping walls was surmounted by a small pyramid. There was, however, an essential difference between the two. At Abydos the nature of the subsoil compelled the architect to contrive the mummy chamber in the interior of his own structure; at Thebes, on the other hand, there was nothing to prevent him from being faithful to a tradition which had manifest advantages, and to intrust the corpse to the keeping of the earth, at a depth below the surface which would ensure it greater safety both from violence and from natural causes of decay. At Thebes the rock was soft enough to be cut with sufficient ease, and yet firm enough to be free from all danger of settlement or disintegration. The soil of all this region is honeycombed with mummy pits, which have long ago been pillaged and are now filled up with sand. The superstructure was built above the well and inclosed the funerary chapel. Sometimes it was surmounted by a small pyramid; sometimes it was a quadrangular mass standing upon a surbase, with a pilaster at each angle and a boldly projecting cornice at the top. The oldest of the known tombs of Apis may be taken as specimens of this latter class, which must also have been represented at Thebes. These are contemporary with the eighteenth dynasty, and were discovered by M. Mariette at Sakkarah.[266] [266] _Athenæum Français_, 1855, p. 55 (_Renseignements sur les soixante quatre Apis trouvés dans le Sérapeum de Memphis_). [Illustration: FIG. 189.--Theban tomb from a bas-relief. (From Wilkinson, ch. xvi.)] These little monuments have either been destroyed since 1851 or covered by the sand (see Fig. 190). The other type is that of the _Speos_. We have here seen that it dates from the Ancient Empire, but came into general employment and obtained its full development under the First and Second Theban Empires. We have already given some idea of the architectural character and of the decoration of the royal sepulchres, we must now indicate the peculiarities which in these respects distinguish the tombs of the kings from those of their subjects.