3. Daughter of Ptolemy III. Euergetes, sister and wife of Ptolemy IV. Philopator. She seems to be erroneously called Eurydice by Justin (xxx. 2), and Cleopatra by Livy (xxvii. 4). Her presence greatly encouraged the troops at the battle of Raphia (217), in which Antiochus the Great was defeated. Her husband put her to death to please his mistress Agathocleia, a Samian dancer (between 210 and 205). She was worshipped as [Greek: Thea Philopator]; she and her husband as [Greek: Theoi Philopatores] (Polybius v. 83, 84, xv. 25-33). 4. Youngest daughter of Ptolemy XIII. Auletes, and sister of the famous Cleopatra. During the siege of Alexandria by Julius Caesar (48) she was recognized as queen by the inhabitants, her brother, the young Ptolemy, being then held captive by Caesar. Caesar took her with him to Rome as a precaution. After Caesar's triumph she was allowed to return to Alexandria. After the battle of Philippi she was put to death at Miletus (or in the temple of Artemis at Ephesus) by order of Mark Antony, at the request of her sister Cleopatra (Dio Cassius xlii. 39; Caesar, _Bell. civ._ iii. 112; Appian, _Bell. civ._ v. 9). AUTHORITIES.--For general authorities see article PTOLEMIES. The article "Arsinoe" in Pauly-Wissowa's _Realencyclopadie_ contains a full list of those who bore the name, and also of the numerous towns which were called after the various princesses. FOOTNOTE: [1] The appendix to pt. ii. of the Tebtunis series of papyri (Grenfell, Hunt and Goodspeed, 1907) contains a lengthy account of the topography of the Arsinoite nome. ARSINOITHERIUM (so called from the Egyptian queen Arsinoe), a gigantic horned mammal from the Middle Eocene beds of the Fayum, Egypt, representing a sub-order of Ungulata, called Barypoda. The skull is remarkable for carrying a huge pair of horn-cores above the muzzle, which seem to be the enlarged nasal bones, and a rudimentary pair farther back; the front horn-cores, like the rest of the skull, consist of a mere shell of bone, and were probably clothed in life with horny sheaths. The teeth form a continuous even series, the small canines being crowded between the incisors and premolars; the crowns of the cheek-series are tall (hypsodont), with a distinctive pattern of their own. Although the brain is relatively larger, the bones of the limbs, especially the short, five-toed feet, approximate to those of the Amblypoda and Proboscidea; but in the articulation of the astragalus with both the navicular and cuboid _Arsinoitherium_ is nearer the former than the latter group.