AUTOLYCUS, of Pitane in Aeolia, Greek mathematician and astronomer, flourished about 31 o B.C. His extant works are : Peri Kinoumenes Sphairas, the oldest Greek mathematical treatise preserved to us entire, which contains some simple propositions on the motion of points on the sphere and its circular sections ; and Peri Epitolon kai Duseon, which treats of the apparent rising and setting of the fixed stars. The former is interesting for the light it throws on the development of the geometry of the sphere even before Autolycus and Euclid. (See THEODOSIUS of TRIPOLIS.)