Sam spotted the difference! The clitellum is actually located near the head of a worm, but the one on the book cover seems to be talking out of his....well let's just say he's likely speaking authoritatively on a subject of which he actually knows little about.
Did you know the main purpose of the clitellum is to create a cocoon for developing eggs? Even more interesting...did you know scientists have digitized the brain of a worm and put it into a robot? It actually moved and behaved like a worm!!
You can read about it HERE, HERE and HERE.
Don't forget that while you are reading you should ask yourself questions, challenge the material, consider the source and look for points of view that weren't expressed in the writing.