Mammalian Spongy Bone
There are two basic structural types of bone in mammals, compact and spongy. Spongy bone, also known as cancellous bone, is less dense than compact bone and is composed of a honeycomb-like network of bones called trabeculae. Spongy bone actually looks like a sponge. It is found at the expanded heads of long bones, such as bones of the arms, legs, fingers and toes.