These are the fifteen extra books that are in the Greek Septuagint (though the same book may be referred to differently):
1. Tobit/Tobias
2. Judith
3. Wisdom of Solomon/Wisdom
4. Ecclesiasticus / Sirach
5. I Maccabees
6. II Maccabees
7. Baruch/Baruch 1-5
8. Epistle of Jeremiah/Baruch 6
9. Additions to Esther/Esther 10:4-16:24
10. Prayer of Azariah and the Song of the Three Young men/Daniel 3:24-90
11. Susanna/Daniel 13
12. Bel and the Dragon/Daniel 14
13. I Esdras/3 Esdras (sometimes called I Esdras)
14. 2 Esdras/4 Esdras (sometimes called 2 Esdras)
15. Prayer of Manasseh
Since Catholics consider these books canon, therefore they do not call them Apocrypha but deuterocanonical, meaning later canon. The Council of Trent in 1546, declared the Apocrypha as canon, except for 3 Esdras, 4 Esdras and the Prayer of Manasseh which they call apocryphal. In the Catholic Bible, these additional writings within the books themselves, for example, “Susana” becomes Daniel 13, and “Bel and the Dragon” becomes Daniel 14, while the Protestant Bible only has 12 chapters to the book of Daniel. (from http://www.truthnet.org/Bible-Origins/6_The_Apocrypha_The_Septugint/index.htm#_ftn2)
Also, from http://en.wikipedia.org/wiki/Septuagint:
All the books of western canons of the Old Testament are found in the Septuagint, although the order does not always coincide with the Western ordering of the books. The Septuagint order for the Old Testament is evident in the earliest Christian Bibles (4th century).[10]
Some books that are set apart in the Masoretic text are grouped together. For example, the Books of Samuel and the Books of Kings are in the LXX one book in four parts called Βασιλειῶν ("Of Reigns"). In LXX, the Books of Chronicles supplement Reigns and it is called Paraleipoménon (Παραλειπομένων—things left out). The Septuagint organizes the minor prophets as twelve parts of one Book of Twelve.[10]
Some scriptures of ancient origin are found in the Septuagint but are not present in the Hebrew. These additional books are Tobit, Judith, Wisdom of Solomon, Wisdom of Jesus son of Sirach, Baruch, Letter of Jeremiah (which later became chapter 6 of Baruch in the Vulgate), additions to Daniel (The Prayer of Azarias, the Song of the Three Children, Susanna and Bel and the Dragon), additions to Esther, 1 Maccabees, 2 Maccabees, 3 Maccabees, 4 Maccabees, 1 Esdras, Odes, including the Prayer of Manasseh, the Psalms of Solomon, and Psalm 151.
Finally, from http://www.justforcatholics.org/a48.htm:
The Protestant and Catholic Bible are identical except for a set of books called the apocrypha or deuterocanonicals.
The apocrypha consists of 15 pieces of Jewish literature written around 200 years B.C. They are included with the Greek translation of the Hebrew scriptures known as the Septuagint. Seven of these books (First and Second Maccabees, Tobit, Judith, Wisdom, Baruch and Ecclesiasticus, also known as Sirach) and additions to Esther and Daniel, are considered canonical by the Roman Catholic Church. Protestants do not accept them as part of the Holy Scriptures.
Hope that helps!
God bless you and yours!