plete separation results in the formation of double or Siamese-like twins. Compare Balanoglossus; and consult A. Willey, Amphioxus and the Ancestry of the Vertebrates (New York, 1894). See the articles on the evolution of the alimentary, circulatory, muscular, nervous, and respiratory systems, under Alimentary System, etc.
AMPHIP'ODA (Gk. nom. neut. pi., from a/upc, amphi, around + noig, pons, foot). An order of crustaceans, distinguished by the sessile, lateral eyes, and the greatly compressed body. They are mostly of small size, and some very minute. Their name alludes to the peculiar
arrangement of the so-called walking-feet, four
pairs of which point forward and three back-
ward. The abdomen or "tail" is also a powerful
locomotive organ, and assists the animal in jump-
ing, which is its usual mode of progression. Even
in swimming its movements are chiefly a succes-
sion of jumps. The amphipods are usually
plainly colored, but some forms are very hand-
some. A large number of species is known, liut
zoologists are by no means agreed as to their
classification, some making only two, and some
as many as nine, families. They occur in both
fresh and salt water, and are especially abundant
along sandy beaches, where they skip about in
such a lively manner that they are called beach-
fleas or sand-hoppers. They are widely distrib-
uted over the world, occurring even in the Arctic
regions, and are of great practical importance as
food for fishes. See Beach-flea, and Crustacea.
AMPHIP'OLIS (C4k. ' Afi<f,iwo2.ic) . A city
of ancient Macedonia, situated in a deep bend
of the Strj'mon, about three miles from the sea
(Map: Turkey in Europe, D 4). Its position
made it important as the port of entry for the
fertile Strymon Valley and Thrace; and the
neighborhood yielded timber for ships, as well as
gold and silver. It belonged originally to the
Edonians, a Thracian people, and was called, on
account of the roads which met here, 'Ewea
'o6ot (Nine Ways). The first who attempted to
colonize .it, Aristagoras of Miletus, was cut off
with his followers by the Edonians. The Atheni-
ans next tried to gain possession of it. Their first
army, amounting to 10,000 men, was utterly cut
to pieces at Drabescus, 465 B.C, but their second,
437 B.C. under Hagnon, son of Nicias, was suc-
cessful. The Thracians were expelled and a new
city built, to which Hagnon gave the name Am-
phipolis, because it had the river on both sides.
Owing to its mixed population, Amphipolis was not friendly to Athens, and in 424 B.C. readily joined the Spartan Brasidas. The Athenian general, Cleon, having been sent to recover the city, was defeated and slain in a battle fought near its walls in 422 B.C., Brasidas also falling in the engagement. Though nominally restored to Athens by the peace of Nicias, Amphipolis seems to have remained independent until its surrender to Philip of Macedon. At Amphipolis was situated the chief mint of the Macedonian kings, and under the Romans it was the capital of Eastern Macedonia. In the Middle Ages it was called Popolia. Its site is now occupied by a Turkish town, but a few of its ruins are still visible. Consult: Leake, Travels in Northern Greece (London, 1835); and Heuzey and Daumet, Mission archéologique en Macédonie (Paris, 1876).
AM'PHISB.ÆNA (Gk. afifiQ, amphis, on both ends + (ialveiv, bainein, to go). The type genus of a family of degraded, limbless lizards, of the general appearance of snakes or worms, found only in the West Indies and South America. The best known is the sooty or dusky species, Amphislxiena fuliginosa. The body is 18 to 24 inches long and nearly the same thickness throughout; head small, eyes small, ears covered with skin, and tail very short. It tunnels under ground, feeding on insect larva; and worms. As it moves either way with equal ease, rumor
gave it two heads, and asserted that when cut in
twain the parts would find eacli other and re-
unite. Its dried and jmlverized flesh was sup-
posed to possess miraculous curative properties.
AMPHIS'SA (Gk. "A/i^iaaa). The official
name of Salona, the capital of the Greek nome of
Phocis (Map: Greece, D 3). It is situated
31 miles northeast of Lepanto, at the western
foot of the Parnassus, a few miles from the site
of Delphi. The town lies in a fertile plain,
and has trade in oil, tobacco, and grain. A
road runs to the harbor of Itea, five miles to
the south, on the Bay of Salona. It is on the
site of the ancient Amphissa. Pop., 1896, 5416.
AM'PHITHE'ATRE (Gk. ἀμφιθέατρον, amphitheatron, a double theatre, from ἀμφί, amphi, on both sides + θέατρον, theatron, a theatre). An architectural structure invented by the Romans for exhibiting gladiatorial combats, fights of wild beasts, and other spectacles. These contests were at first given in the Roman Forum, within hastily contrived wooden scaffoldings, or in the Circus. But in 59 B.C., Curio, wishing to surpass all his predecessors in the sumptuousness of his shows, erected two wooden theatres, back to back, where dramatic performances were given simultaneously; and when these were over the two theatres were made to revolve and close up. Their tiers of seats inclosed an arena suited for the contests which then followed. Perhaps the model was found in the cities of Campania; for Pompeii had an amphitheatre as early as 70 B.C. Cæsar first erected, in 46 B.C., a permanent structure of this kind in wood, and it was called amphitheatre, from its shape, or theatrum venatorium or "theatre of the chase," from the kind of contests held in it. Still, combats of gladiators and wild beasts continued to be given in the Circus and the Forum. In 30 B.C., under Augustus, Statilius Taurus built the first amphitheatre that was partly of stone, in the Campus Martius: it remained the only one in Rome not entirely of wood until the erection of the Coliseum by Vespasian, whose son and successor, Titus, dedicated the edifice in 80 A.D. Even the upper part of the Coliseum itself was originally of wood until the restoration, after a great fire, in 223. The example of Rome was followed by all the cities of any importance throughout the Empire, where the love of bloody sports, so repugnant to the Greeks, spread rapidly. Amphitheatres were erected throughout Italy and Sicily (Verona, Puteoli, Capua, Pola, Syracuse, Pompeii, etc.), Spain (Tarragona, Italica), France (Arles, Nîmes, Bordeaux, Saintes, etc.), England (Silchester, Cirencester), Germany, North Africa (El-Jemm), Asia Minor (Pergamum, Cyzicus), Greece (Corinth, Sparta.) The ruins of almost a hundred have been found. Those that are well preserved
