The spinal cord begins at the occipital bone and extends down to the space between the first and second lumbar vertebrae; it does not extend the entire length of the vertebral column.
Earthworms are invertebrates, lacking a skeleton. To support and shape the body, they are filled with coelomic fluid. Earthworms sometimes appear to have a belt or saddle around their bodies; this is a clitelum, a structure containing maturing eggs.
Tapeworms lack a mouth and a digestive tract. Describe the tapeworms. They are segmented, flat, have no digestive system, and absorb all nutrients through the tegument (no mouth).