Several monarchs of the Sin series--i.e. monarchs into whose names the word Sin, the name of the Moon-god, enters as an element--now present themselves. The most important of them has been called Zur-Sin. This king erected some buildings at Mugheir; but he is best known as the founder of the very curious town whose ruins bear at the present day the name of Abu-Shahrein. A description of the principal buildings at this site has been already given. They exhibit certain improvements on the architecture of the earlier times, and appear to have been very richly ornamented, at least in parts. At the same time they contain among their debris remarkable proofs of the small advance which had as yet been made in some of the simplest arts. Flint knives and other implements, stone hatchets, chisels, and nails, are abundant in the ruins; and though the use of metal is not unknown, it seems to have been comparatively rare. When a metal is found, it is either gold or bronze, no trace of iron (except in ornaments of the person) appearing in any of the Chaldaean remains. Zur-Sin, Rim-Sin, and three or four other monarchs of the Sin series, whose names are imperfect or uncertain, may be assigned to the period included between B.C. 1700 and B.C. 1546. Another monarch, and the only other monumental name that we can assign to Berosus’s fourth dynasty, is a certain Nur-Vul, who appears by the Chaldaean sale-tablets to have been the immediate predecessor of Rim-Sin, the last king of the _Sin_ series. Nur-Vul has left no buildings or inscriptions; and we seem to see in the absence of all important monuments at this time a period of depression, such as commonly in the history of nations precedes and prepares the way for a new dynasty or a conquest. The remaining monumental kings belong almost certainly to the fifth, or Arabian, dynasty of Berosus, to which he assigns the period of 245 years --from about B.C. 1546 to B.C. 1300. That the list comprises as many as fifteen names, whereas Berosus speaks of nine Arabian kings only, need not surprise us, since it is not improbable that Berosus may have omitted kings who reigned for less than a year. To arrange the fifteen monarchs in chronological order is, unfortunately, impossible. Only three of them have left monuments. The names of the others are found on linguistic and other tablets, in a connection which rarely enables us to determine anything with respect to their relative priority or posteriority. We can, however, definitely place seven names, two at the beginning and five toward the end of the series, thus leaving only eight whose position in the list is undetermined.