Plate 7. 



1-24. Porocidaris Cobosi A. Ag. 



1. Tri dentate pedicellaria. x 11. 



2. Smaller tridentate pedicellaria. x 11. 



3. Developmental stage of tridentate pedicellaria. x 11. 



4. Very small tridentate pedicellaria. x 55. 



5. Valve of large tridentate pedicellaria. x 30. 



6. Interior view of base of valve of small tridentate pedicellaria. x 55. 



7. Calcareous particles from pedicels, x 156. 



8. Abactinal primary spine. Nat. size. 



9. Ambital primary spine. Nat. size. 



10. I?ase of same spine, x 5. 



11. Tip of same spine, x 5. 



12. End view of same tip. x 5. 



13. Ambital primary spine of small individual, x 3. 



14. Actinal primary spine, x 5. 



15. Side view of same spine, x 5. 



10. Smaller actinal primary spine, x 5. 



17. Smallest actinal primary spine. x 5. 



18. Young abactinal primary spine, x 5. 



19. Somewhat younger abactinal primary spine, x 5. 



20. Youngest abactinal primary spine, x 5. 



21. Interambulacral secondary spine. x 11. 



22. Another interambulacral secondary spine, x 11. 



23. Ambulacral secondary spine, x 11. 

 21. Actinal miliaries. x 11. 



