Across
- 10. closes or covers aperture
- 11. tactile sense organs
- 12. stabilizer fin
- 15. collect and expel blood
- 17. cold blooded animals
- 20. gas filled sac
Down
- 1. tail fin
- 2. two fins on the side
- 3. receives blood from circulatory system
- 4. amphioxi
- 5. tiny, rough scales
- 6. ascidians
- 7. cartilaginous
- 8. bony fish
- 9. actionptergii
- 13. rhina ancylostoma
- 14. ancient extant
- 16. cartilaginous skeletal rod
- 18. releases excretory and genital
- 19. class myxini