The polyp stage of Aurelia.
The smallest polyps, the pink and white ones near the centre of the photograph, are just a few millimetres long. These are scyphistomae; the white colour is their tissue, the pink is from food. The much longer polyps are strobilae (singular = strobila), and their red colour is due to natural pigmentation.
Prepared by M. Dawson and K. Raskoff.