The art form for which the Olmecs are best known, the monumental stone heads weighing up to forty tons, are generally believed to depict kingly leaders or possibly ancestors. Other symbols abound in their stylistic repertoire, including several presumably religious symbols such as the feathered serpent and the rain spirit, which persisted in subsequent and related cultures until the middle ages. Comparatively little is known of their magico-religious world, although the clues that we have are tantalising. Technically, these include all non- secular items, of which there is a fascinating array. The best- known forms are jade and ceramic figures and celts that depict men, animals and fantastical beasts with both anthropomorphic and zoomorphic characteristics. Their size and general appearance suggests that they were domestically- or institutionally-based totems or divinities. The quality of production is astonishing, particularly if one considers the technology available, the early date of the pieces, and the dearth of earlier works upon which the Olmec sculptors could draw. Some pieces are highly stylised, while others demonstrate striking naturalism with deliberate expressionist interpretation of some facial features (notably up- turned mouths and slit eyes) that can be clearly seen in the current maskette.