Beneath each of the sixteen spouts appear eight winged sirens with outstretched wings and hands resting on their chests, each alternating with eight ithyphallic satyrs.
The sirens are traditionally charged with ambiguity: through their song they could bring joy, foretell the future, and also herald death. At the same time, they were regarded as guardians of the deceased’s memory and as guides escorting souls to the afterlife.
According to Pythagorean doctrine, the eight notes emitted by each siren together formed the harmony of the celestial spheres, themselves composed of eight heavens.