Second Syrian War
The Second Syrian War was fought between Antiochus I and Ptolemy II when Antiochus invaded Syria, this time in 260 B.C. Antigonus, Macedonian ally of Antiochus, this time wasn't busy fighting a war that Ptolemy had instigated to keep him occupied, and so the forces of Ptolemy II were defeated by Antigonus in a naval battle off Cos in 258 B.C. Ptolemy made peace in 255 B.C.
Encyclopedia of Military History, Dupuy & Dupuy, 1979