Chthonia; an annual ritual of Demeter in Hermione

"The goddess herself is called Chthonia, and Chthonia is the name of the festival they hold in the summer every year... They conduct the festival like this.

The procession is headed by the priests of the gods and by all those who hold the annual magistracies; both men and women follow after them. It is now a custom that some who are still children should honor the goddess in the procession as well. These wear white clothing and wreaths upon their heads. Their wreaths are woven from a flower that they call ksomosandalon, which seems to be a hyacinth, judging from its size and color; the same letters of mourning are even upon it. Men lead from the herd a heifer - fastened with bonds, and still unruly due to her wildness - following those who form the procession. Having driven the heifer to the temple, some loose her from the ropes so that she may rush into the sanctuary; others, who up until then have been holding the doors open, when they see the heifer within the temple, close the doors.

Four old women, left behind inside, make an end of the heifer.

Whoever gets the chance slices the throat of the cow with a sickle. Afterwards, the doors are opened, and those who are appointed drive up a second heifer, and a third after that, and yet a fourth. The old women make an end of them all in the same way, and there is yet another wonder in this sacrifice. On whichever of her sides the first heifer falls, all the others must fall on the same.

The sacrifice is performed by the Hermionians in the manner described. Before the temple stand a few statues of the women who have served Demeter as her priestess, and on passing inside, you see seats on which the old women wait for each of the heifers to be driven in, and images, of no great age, of Athena and Demeter.

But the thing itself that they revere more than all else, I never saw, not yet has any other man, whether strange or Hermionian. Only the old women know what it is."

Pausanias, (2.35.5-8), trans. W.H.S. Jones, modified by Sarah Iles Johnston, excerpt taken from "Demeter in Hermione: Sacrifice and Ritual Polyvalence," source.