Ianthella basta or elephant ear sponge is a species of fan-shaped sponge in the class Demospongiae. It is also known as the paper sponge or scroll sponge. Sponges are marine invertebrates with a jellylike mesohyl sandwiched between two layers of cells. They are filter feeders maintaining a flow of water through their structure which passes out through large openings called oscula. They have a fragile skeleton of stiff spicules.