GOR'DIUS, a genus of annelida, of the very simplest structure; very much elongated and threadlike, with no greater marks of articulation than slight transverse folds, no feet, no gills, no tentacles, although there is a knotted nervous chord. The mouth is a mere pore.at one end of the anima]; the other end or tail is slightly bifid, and has been often mistaken for the head. The species inhabit moist situations, are sometimes found ou the leaves of plants, but more frequently in stagnant pools, and in mud or soft clay, through which they work their way with great ease. They often twist themselves into complex.knots, whence their name gordius, from the celebrated Gordian knot—and many of them are sometimes found thus twisted together; but they are also often to be found extended in the water. The most common species in Britain is G, aquaticus, of the popular name is HAIR EEL; and a notion still prevails in many parts of the country, that it is nothing else than a horse-hair, which has somehow acquired life by long immersion in water, and which is destined in due course of time to become an eel of the ordinary kind and dimensions; in proof of all which many an honest observer is ready to present himself as an eye-witness who has often seen these very slender eels in his walks. A popular notion prevails in Sweden, that the bite of the gordius causes
whitlow. When the pools in which the gordius lives are dried tjp, it becomes shriv eled, and apparently' lifeless, but revives on the application of moisture. The Abbe Fontana kept one in a drawer for three years, and although perfdctly dry and hard, it soon recovered vigor on being put into water. Gordii arc extremely common in the Thames.