This image is a symmetrisation piece (that I'm so curious for) that is derived from a radiographic image of the crust of a spider crab that I've found diving in the sea years ago... Actually, it was not a plain (conventional) X-ray, but rather a "mammographic" image, for the crust of this creature is so very thin for being able to be shot properly (with proper exposure) with a conventional x-ray device... The mammographic image was shot in 1997 with permissions of the radiology specialists in the hospital of the medical faculty that I was attending...