1. Worms Connie Davis March 4 th 2009 Biology Extra credit

2. Flatworm Flatworms are soft, flattened worms that have tissues and internal organ systems. They are the simplest animals to have three embryonic germ layers, bilateral symmetry, and cephalization.

3. Roundworm Roundworms are unsegmeted worms that have pseudocoeloms and digestive systems with two openings a mouth and an anus.

4. Annelids Annelids are worms with segmented bodies. They have a true coelom that is lined with tissues derived from mesoderm.