Easton's Bible Dictionary (1897)
Ten cities=deka, ten, and polis, a city, a district on the east and south-east of the Sea of Galilee containing “ten cities,” which were chiefly inhabited by Greeks. It included a portion of Bashan and Gilead, and is mentioned three times in the New Testament (Matt. 4:25; Mark 5:20; 7:31). , “city of the Scythians”, (ancient Bethshean, the only one of the ten cities on the west of Jordan), Hippos, Gadara, Pella (to which the Christians fled just before the destruction of Jerusalem), Philadelphia (ancient Rabbath-ammon), Gerasa, Dion, Canatha, Raphana, and Damascus.
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
DECAP'OLIS (ten cities), a region noticed three times in the Bible. Matt 4:25; Map of Decapolis. ") Mark 5:20; Mark 7:31 It lay near the Sea of Galilee probably on both sides of the Jordan. c. 65; but as other cities grew up, writers are not agreed as to the names of the ten cities. Pliny gives them as follows: Scythopolis, Hippos, Gadara, Pella, Philadelphia, Gerasa, Dion, Canatha, Raphana, Damascus. Six are deserted, and none have many inhabitants except Damascus.
Hitchcock's Bible Names (1869)
containing ten cities