Jean Delville's "Treasures of Satan"

leading from: 
Delville's influence on Giger
and also:
The Zig Zag Devil via Jean Delville & HR Giger to James Cameron's Alien Queen

a) Idol Of Perversity

Flemish Symbolist Jean Delville in the year of 1891, the same year that the Bradshaw cave in the Kimberley region was discovered, drew the composition Idol Of Perversity that displays the snaking form with it's tail slithering between her breasts and tongues of like eminating from her head.

Zig Zag Devil,
 (source bradshawfoundation.com)

The Idol of Perversity by Jean Delville 1891
(source of image: http://imageevent.com/ )

The three prongs in the face of the rock painting are the remains of a human figure like the one on the far left in the picture and Jean Delville perhaps translate this into his drawing translates into the edges of the veil either side of her face and naked bosom. Exactly how Jean Delville came to know about the cave painting within that year is unknown but it's easy to imagine that he saw images of Bradshaw's findings one way or another that year.

Jean Delville's Treasures of Satan

b.) Treasures of Satan

However this thing we know to be the Zig Zag Devil, it appears that Jean Delville developed the idea further into the painting"Treasures of Satan" and it was first exhibited in 1895. The zigzagging tentacles have been developed into ones of a monstrous size on the back of a man who resembles a ballet dancer, as if once they were angel's wings and have been transformed into something hellish.

Wikipedia talks about the rest of the themes of the composition saying that "Delville was a great admirer of Eduard Schuré’s The Great Initiates, and it could well be that Satan’s Treasures is inspired by an episode from the Initiation of Isis in Schuré’s book. In the relevant scene, Schuré describes the novice’s failure of an early test, the temptation of the senses. Wrapped in a dream of fire, the novice becomes drunk with the heavy perfume of a seductive woman, and later falls asleep, after wildly satisfying his desire. This failure is described by his hierophant as a fall into the abyss of matter." (source wikipedia.org/wiki/Jean_Delville)