Spongipellis pachyodon (Pers.) Kotlaba & Pouz. Fruit body 5-20cm across, crust-like or spreading on surface of logs, often many smaller patches or caps fused together into sheets. If fruit body is projecting, cap-like, then upper surface is finely tomentose, cream colored; lower surface with tooth-like or flattened-spiny projections up to 12mm long, white to cream color. Flesh tough, corky; white. Odor mild. Taste mild. Spores oval, smooth, 5.5-7.5 x 5-6µ. Deposit white. Habitat on fallen logs of maple, oak, and beech. Found widely distributed throughout North America. Season July-October. Not edible.