The Yoni
While the symbols of the male have claimed a worldwide homage, the symbols of the female have by no means been neglected, either by ancient Phallicism or by Christianity. The usual and natural symbol of femininity is a doorway or archway, suggestive of the vulva or external genitals. This is often conventionalized into an oval, a circle, a crescent, a vesica piscis or fish’s bladder (a term applied by architects to an oval church window which narrows at top and bottom), a diamond-shaped lozenge or an inverted triangle. Concerning this last symbol, which is sometimes referred to as the Greek letter Delta, Inman says:
The selection of name and symbol was judicious, for the words Daleth (Hebrew) and Delta (Greek) signify the door of a house, and the outlet of a river, while the figure reversed, with the heavy side above, modestly represents the fringe with which the human delta is overshadowed.
This sacred doorway of life, through which every human soul must enter this world, has been deemed worthy by the Roman Catholic Church to frame around the Blessed Virgin and Holy Child, either as a vesica piscis or in some other conventionalized form, unmistakably yonic.
(p. 241)