IN our third volume we have found it impossible to retain the order of the Books of the Septuagint followed by Dr Swete. The Books of Esther, Judith and Tobit are found in many of the MSS. which contain the Historical Books. It seemed therefore desirable to publish them first in this Volume before dealing with the Sapiential Books which are generally found in a different set of MSS. Some time ago we decided to defer the publication of the Psalter till a later date. The three books which we now publish form the third group in Dr Rahlfs's Verzeichnis. They are sometimes found in the MSS. which have the Historical Books, but more often new MSS. have to be quoted, and we have had to make a separate selection for each Book, and to give separate lists of the MSS. used for each Book. The symbols used for MSS. in the earlier volumes have been retained, but those used for MSS. no longer cited have been re-assigned. The original scheme of adding a numeral after the letter (a2 etc.) to provide a separate symbol for each MS. used has proved unworkable. Where the number of authorities quoted is large, valuable space is lost. We find ourselves compelled to use a single letter for each minuscule quoted, and to provide a separate list for each Book.