This document provides information about segmented worms of the phylum Annelida. It discusses three main classes of annelids: Oligochaeta (earthworms), Hirudinea (leeches), and Polychaeta (marine worms). It describes the habitats and behaviors of different annelid classes, including how earthworms live underground, leeches live near freshwater, and marine worms live in the ocean. The document also covers anatomical features of annelids like their segmented bodies and adaptations that allow them to live on land or in varied environments.