CETRA, or CAETRA, a target, _i.e._ a small round shield, made of the hide of a quadruped. It formed part of the defensive armour of the Osci, and of the people of Spain, Mauritania, and Britain, and seems to have been much the same as the target of the Scotch Highlanders. The Romans do not appear to have used the cetra; but we find mention of _cetratae cohortes_ levied in the provinces. Livy compares it to the _pelta_ of the Greeks and Macedonians, which was also a small light shield. CHALCĬOĒCĬA (χαλκιοίκια), an annual festival, with sacrifices, held at Sparta in honour of Athena, surnamed _Chalcioecus_ (Χαλκίοικος), i.e. the goddess of the brazen-house. Young men marched on the occasion in full armour to the temple of the goddess; and the ephors, although not entering the temple, but remaining within its sacred precincts, were obliged to take part in the sacrifice. CHALCUS (χαλκοῦς), a denomination of Greek copper-money. Bronze or copper (χαλκός) was very little used by the Greeks for money till after the time of Alexander the Great. The χαλκία πονηρὰ at Athens issued in B.C. 406 were a peculiar exception; and they were soon afterwards called in, and the silver currency restored. It is not improbable, however, that the copper coin called χαλκοῦς was in circulation in Athens still earlier. The smallest silver coin at Athens was the quarter-obol, and the χαλκοῦς was the half of that, or the eighth of an obol. Its value was somewhat more than 3-4ths of a farthing. The χαλκοῦς in later times was divided into lepta, of which it contained seven. In later times the obol was coined of copper as well as silver. CHĂRISTĬA (from χαρίζομαι, to grant a favour or pardon), a solemn feast among the Romans, to which none but relations and members of the same family were invited, in order that any quarrel or disagreement which had arisen amongst them might be made up. The day of celebration was the 19th of February. CHEIRŎNŎMĬA (χειρονομία), a mimetic movement of the hands, which formed a part of the art of dancing among the Greeks and Romans. In gymnastics it was applied to the movements of the hands in pugilistic combat.