Besides this class of burial we find still in use at this time the usual Babylonian trough coffins of terra-cotta, either with a separate cover, or tilted up over the body. The slipper sarcophagus is also naturalised in Babylon (Fig. 133), which, like many of the trough sarcophagi, has a beautiful blue glaze, which, however, easily flakes off. The necropolis in the principal court of the Southern Citadel was full of them. The shape of the slipper sarcophagus, in which the head of the corpse lay below an opening which was closed by a separate cover, appears to date back in Nippur to a very early period. It is evident that a great variety of types of burial were in use in Babylonia. The long trough sarcophagi which here in Babylon were first used in Neo-Babylonian times, and later, with the double-urn coffin and the short high pan coffin, were already common in Fara (Shuruppak), in the prehistoric period, only deeper in shape; while the double-urn coffin first appeared there with the beginning of writing (3000 B.C.). In prehistoric Surgul the body was burnt with the help of high inverted coffins. Interments in underground vaults, which are numerous in Assur, occur very rarely in Babylon, and only under Assyrian domination (?) The methods of burial and their sequence differ in every town where research has been carried on. If it appears amazing that burial by burning should have been practised in Surgul, it must be remembered that up to the present time, with the exception of the lowest levels of Fara, it is the only prehistoric site that has been explored in that part of the world. While the ethnologist and the student of western prehistoric and early culture possesses a wealth of material to illustrate the development of a few centuries, in Babylonia the prehistoric period embraces many thousands of years, and its material is confined to that derived from Surgul and Fara. From Bismaya, where, according to Banks the excavator, burnt interments were found, little has yet been gained, and nothing is known of Telloh in this connection. It also happens that the difference in time between the periods of these culture strata is very great. At Fara the upper layer belongs to the period of the beginning of writing in the fourth or fifth millennium, while the lowest strata 8 or 10 metres lower down belong perhaps to the tenth. This we can only surmise, we cannot prove it. Surgul after its time of prosperity apparently lay deserted for countless centuries, before its occupation in the time of Gudea of which the scanty remains now lie upon the surface. The interval between Nebuchadnezzar and Entemena, which is generally regarded as very long, is, in fact, remarkably short when compared with the duration of the prehistoric period in Babylonia, the length of which it is at present impossible for us to estimate. And what do we know of it? Only a few disconnected strophes from among the great, lengthy, and doubtless