Casson, Stanley: The technique of early Greek sculpture (Oxford, 1933)

Fig. 21. VASE FOUND ON THE SUPPOSED SITE
OF SPINA, showing votary at an altar with small statues
of the nine muses in the background.
These statues are shown as small either because they were, in fact,
small, or else because they stood at a distance behind the altar.
In type they represent figures of the late seventh century.