Mnaseas is reckoned to have been a pupil of a scholar who was chief librarian at what library?
Eratosthenes Eratosthenes of Cyrene ( ; Greek: Ἐρατοσθένης ὁ Κυρηναῖος , ] ;  – ) was a Greek mathematician, geographer, poet, astronomer, and music theorist. He was a man of learning, becoming the chief librarian at the Library of Alexandria. He invented the discipline of geography, including the terminology used today.
Theodas of Laodicea Theodas (or Theudas) of Laodicea, was a Pyrrhonist philosopher and physician of the Empiric school, in the 2nd century. He is mentioned by Diogenes Laertius as being a native of Laodicea, a pupil of Antiochus of Laodicea, and a contemporary of Menodotus. A physician of this name is also quoted by Andromachus.