Naus or Naos was the great-grandson of Eumolpus of Eleusis. He obeyed an oracle from Delphi and established a sanctuary of Demeter, surnamed Eleusinian, in Pheneus. The people of Pheneus performed a ritual to the goddess similar to the ceremonies at Eleusis. The Greater Rites took place every other year. Two large stones, fitted one to the other, stood beside the sanctuary. These stones were known as the Petroma. During the celebration, the people of Pheneus removed sacred writings that refer to the rites from the Petroma, read them in the hearing of the initiated, and returned them on the same night. The Petroma also contained a mask of Demeter Cidaria. The priest of the Greater Rites wore the mask and used a rod to beat “the underground folk”. The reason for the ritual was obscure, as was another element of the story narrated by Pausanias. The Pheneatae claimed that Demeter had visited their town long before Naus and gave them pulses in return for their generous hospitality. The only pulse she refused to provide them with was the bean, but the reason was not to be divulged to the uninitiated. The Pheneatae who welcomed Demeter were Trisaules and Damithales, who also built a temple of Demeter Thesmia under Mount Cyllene and established rites for her.