2. Excretory

3. Respiration

4. Circulatory

5. Skeletal/Muscular

6. Reproductive

7. Nervous

8. Development

2. Cnidaria

3. Platyhelminthes

4. Nematoda

5. Annelida

6. Mollusca

7. Arthropoda

8. Echinodermata

9. Chordata

10. Agnatha: lamprey

11. Chondrichthyes: sharks

12. Osteichthyes: bony fish

13. Amphibia

14. Reptilia

15. Aves

16. Mammalia