[In The Red Book we read the following.]:

The moon is dead. Your soul went to the moon, to the preserver of souls.
Thus the soul moved toward death. I went into the inner death and saw that outer dying is better than inner death. And I decided to die outside and to live within. For that reason I turned away and sought the place of the inner life. ~Carl Jung, The Red Book, Page 268.

[In The Psychology of Kundalini Yoga we read the following]:

Dr. Jung: Yes, the anima is the Kundalini.(Footnote 31)

That is the very reason why I hold that this second center, despite the Hindu interpretation of the crescent being male, is intensely female, for the water is the womb of rebirth, the baptismal fount.

The moon is of course a female symbol; and, moreover, I have a Tibetan picture at home in which Shiva is depicted in the female form, dancing on the corpses in the burial ground.

At all events, the moon is always understood as the receptacle of the souls of the dead.

They migrate to the moon after death, and the moon gives birth to the souls in the sun. She first gets quite full of dead souls—that is the pregnant full moon—and then she gives them to the sun, where the souls attain new life (a Manichean myth).
So the moon is a symbol of rebirth. Then the moon in this cakra is not above—it is below, like a cup from which flows the offering of souls to the cakras above, manipura and anvhata. You see, there is the sun myth again. ~Carl Jung, The Psychology of Kundalini Yoga, Page 22

41 Jung’s interpretation of the Kundalini as the anima may in part have been suggested by the following description of her cited in The Serpent Power: “She . . . is the ‘Inner Woman’ to whom reference was made when it was said, ‘What need have I of outer women? I have an Inner Woman within myself’ ” (1st ed., 272).

This sentence is heavily marked in Jung’s copy of the book; the whole phrase is cited in his “Die Beschreibung der beiden Centren Shat-chakra Nirupana” (2), and the last phrase, “I have an Inner Woman within myself,” is cited again in his “Avalon Serpent” manuscript.

In “Concerning Mandala Symbolism” (1950), while commenting on a mandala painted by a young woman in which a coiled snake appeared, Jung said of the snake: “It is trying to get out: it is the awakening of Kundalini, meaning that the patient’s chthonic nature is becoming active. . . . In practice it means becoming conscious of one’s instinctual nature.” CW, vol. 9, part 1, §667. ~Footnote #41, The Psychology of Kundalini Yoga, Page 22.