Sentence:  It would seem, therefore, that what we have on the Phasian phiale is the <WSD>Python</WSD> coiled round the omphalos....Paintings on Greek pottery and coins have preserved many an example of gods seated on an omphalos, including those of Apollo, Nike, Asclepius and others.413 <WSD>Python</WSD> on the omphalos must have carried some symbolic meaning. 
Meaning of the word marked with <WSD> tags:  The earth-dragon of Delphi, represented as a serpent, killed by Apollo.