PISCES (the fishes)  , in astronomy, the twelfth sign of the zodiac (q.v.), represented by two fishes tied together by their tails and denoted by the symbol X . It is also a constellation, mentioned by Eudoxus (4th century B.e.)and Aratus (3rd century B.C.); and catalogued by Ptolemy (38 stars), Tycho Brahe (36) and Hevelius (39) . In Greek legend Aphrodite and Eros, while on the banks of the Euphrates, were surprised by Typhon, and sought safety by jumping into the water, where they were changed into two fishes . This fable, however, as in many other similar cases, is probably nothing more than an adaptation of an older Egyptian tale. a Piscium, is a fine double star of magnitude 3 and 4; 35 Piscium, is another double star, the components being a white star of the 6th magnitude and a purplish star of the 8th magnitude . Piscis australis, the southern fish, is a constellation of the southern hemisphere, mentioned by Eudoxus and Aratus, and catalogued by Ptolemy, who described 18 stars . The most important star is a Piscis australis or Fomalhaut, a star of the first magnitude . Piscis volans, the flying fish, is a new constellation introduced by John Bayer in 1603 .