BETULEIUS, SIXTUS, a grammarian, Latin poet, and philosopher, born at Memmingen, A.D. 1500. His real name was Birck. He taught the belles-lettres and philosophy with reputation, and became principal of the college of Augsburg, where he died in 1554. He published various works in prose; and several dramatic pieces. See Betulei Vita, per Jo. Nyseum Scripta; and Adam's Vita Eruditorum.