A broad belt running round the heavens parallel to the ecliptic, and extending about 8° on each side of it. It is the area within which the motions of the sun, moon, and the greater planets lie. The stars in the zodiac have been divided into twelve groups called constellations - ' Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, Pisces. These divisions do not now coincide with the constellations as formerly ; for by the precession of the equinoxes they have been moved back about 25° behind the constellations.