• Codex Sinaiticus (4th century), labeled Aleph: Genesis...Numbers...Joshua (part); Judges...1-2 Chronicles; 1 Esdras; Ezra-Nehemiah; Tobit; Judith; 1 & 4 Maccabees; Isaiah; Jeremiah; Lamentations; the Twelve (incomplete); Psalms; Proverbs; Ecclesiastes; Song of Songs; Wisdom of Solomon; Sirach; Job.
Certain books are missing/lost. Psalms contains Psalm 151 as part of the regular Psalter.
• Codex Vaticanus (4th century), labeled B: Genesis - Deuteronomy; Joshua son of Nun; Judges; Ruth; 1-4 Kingdoms; 1-2 Chronicles; 1 Esdras; Ezra-Nehemiah; Psalms - Sirach; Esther; Judith; Tobit; the Twelve; Isaiah; Jeremiah; Baruch; Lamentations; Letter of Jeremiah; Ezekiel; Daniel
• Codex Alexandrinus (5th century), labeled A: Genesis - 2 Chronicles; the Twelve; Isaiah - Daniel; Esther; Tobit; Judith; 1 Esdras; Ezra-Nehemiah; 1-4 Maccabees; Psalms; Job; Proverbs; Ecclesiastes; Song of Songs; Widsom of Solomon; Sirach
Psalm 151 is included as "outside the number." the Psalms of Solomon is listed in the table of contents for the codex but is not found in the codex itself.
I'm also adding a great quote about the Septuagint from: "Exploring the Origins of the Bible (Acadia Studies in Bible and Theology): Canon Formation in Historical, Literary, and Theological Perspective" by Craig A. Evans & Emanuel Tov. This quote sums up what is so misunderstood.
"Most scholars do not actually believe that there was a book (codex) form of the Septuagint at the turn of the millennia, but they still talk about “the Septuagint,” as if Paul, for example, had gone to the local Alexandrian Bible Society bookstore in Tarsus and purchased his own bound copy of The Septuagint, from which he preached." (Evan & Tov, p.192).