Curtain has three pieces that are connected by long chains. The top is a reflection of the bottom piece, filet crochet with spider cobwebs. The middle piece is smaller and diamond shaped.

Pattern 18 in Magic Crochet.
Shown on cover of Ganchillo Artistico.
Pattern 8, Peek-a-Boo, in Crochet Monthly, #261.
Shown on cover of Crochet d’Art