SELEUCIS(Σελευκίς), a district of Syria, mentioned by Ptolemy,as containing the cities of Gephura, Gindarus, and Imma (5.15.15). Strabo calls it the best of all the districts: it was also called Tetrapolis, on account of its four most important cities, for it had many. These four were, Antioch, Seleuceia in Pieria, Apameia, and Laodiceia (16. p. 749). It also comprehended, according to Strabo, four satrapies; and it is clear that he uses the name in a much wider sense than Ptolemy, who places the four cities of the tetrapolis of Strabo's Seleucis in so many separate districts; Antioch in Cassiotis, Apameia in Apamene, Laodiceia in Laodicene, while he only implies, but does not state, that Seleuceia lies in Seleucis.
[G.W]