Texts witnessed only in the Septuagint

[Edited by Ellopos from Wikipedia articles.]

The Letter of Aristeas or Letter to Philocrates [full text in the Greek original and in English is included here] is a Hellenistic work of the 2nd century BCE, assigned by Biblical scholars to the Pseudepigrapha.

Josephus who paraphrases about two-fifths of the letter, ascribes it to Aristeas and to have been written to a certain Philocrates, describing the Septuagint translation. Though some have argued that its story of the creation of the Greek translation of the Hebrew Bible is fictitious, it is the earliest text to mention the Library of Alexandria.