I. An ancient city of Egypt, capital of the nome or district of Arsinoitis, W. of the Nile, and not far from Lake Mœris. Ptolemy Philadelphia gave it that name in honor of his favorite sister and queen Arsinoe. Originally, however, it was called Crocodilo-polis by the Greeks, because the crocodile there received divine honors from the Egyptians. The ruins of the city may be seen in the vicinity of the modern Medinet el-Fayoom.
II. An ancient city of Egypt, capital of the Heroopolite nome, at the N. W. extremity of the Red sea, near the site of the present town of Suez. Ptolemy Philadelphus considerably en- larged and improved it, and gave it its name, Arsinoe was connected with the Kile by the Ptolemaean canal, and was long the great east-ern emporium of Egypt. Its revenues belonged to Queen Arsinoe and her successors.