DIONYSIUS, a learned geographer, to whom is attributed a Periegesis, or Survey of the Earth, in Greek verse. Some suppose that he lived in the time of Augustus; but Scaliger and Salmasius place him under the reign of Severus, or of Marcus Aurelius. He wrote many other works, but his Periegesis is the only one we have remaining, the best and most useful edition of which is that improved with notes and illustrations by Hill.