Serpens (The snake or serpent) is of particular interest as being the only constellation to be split into two areas seperated by the large constellation Ophiuchus. In ancient times the shapes of the constellations were made by joining the stars with imaginery lines. Serpens was originally depicted as a complete snake being held by Ophiuchus but in when the International Astronomical Union created the constellation boundaries Serpens was divided into two parts to avoid overlapping. The two parts are Serpens Caput (The Head) and Serpens Cauda (The Tail) and can be thought of as two seperate constellations, indeed many books on astronomy will show them as such.