The crumb-or-bread sponge is a thickly encrusting sponge with a glistening bumpy surface. Specimens found intertidally are bright yellow. Specimens from deeper water are darker. The oscula are scattered across the surface of the sponge and may be flush with the sponge surface or on raised mounds. The form of the sponge is variable, depending on its environment. In sheltered areas, branched structures grow from the base. In areas with wave action the surface is convoluted or flat.
The crumb-of-bread sponge is found in the northern Atlantic Ocean, the Mediterranean sea and the Pacific Ocean, as well as around the southern African coast from the northern Cape to Port St Johns. It lives from the intertidal zone in tide pools to a maximum depth of about 15 meters (about 50 feet).