I have to confess, there was some laziness in the creation of this background. I meant to separate out the anatomical sketches of the jellies here and paste them around the image, but I ended up just slapping in the entire page as-is from the public domain book. Sometimes the lazy approach works, like here where it keeps the focus on the center of the image.
Download the full size version of this image here
This is the background for Persistent Ineffable Feelings of Unreality