Chasm Progress 2: The Mud Report / 169-6932_parab mudworm 7/25/2004 So we've rebuilt the larger parabaloid, and some changes have been made to the covering. The underside is covered entirely in burlap, and one layer of stucco mesh is attached to the frame, with a combination of staple guns, and piano wire, to prevent it from falling off under the weight of the mud.