Cytis, is, f.,
an island at the entrance of the Arabian Gulf, producing chrysolite; now Perim , Plin. 6, 29, 34, § 170.
cytis, is, f., = κύτις, an unknown precious stone , Plin. 37, 10, 56, § 154. ...
A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.