Plate 8. 



1-27. Porocidaris variabilis A. Ag. and C'lari 



1. Large pedicellaria. x 23. 



2. Anotlier pedicellaria. x 23. 



3. Another large pedicellaria. x 8. 



4. luterior view of valve of pedicellaria. x 8. 



5. Very small pedicellaria. x 23. 



6. Side view of normal four-valved pedicellaria. x 2.3. 



7. End view of same, x 23. 



8. Abnormal four-valved pedicellaria. x 2.3. 



9. Side view of two-valved pedicellaria. x 11. 



10. End view of same, x 11. 



11. Rear view of same, x 11. 



12. Abactinal primary spine. Nat. size. 



13. Ambital primary spine. Nat. size. 



14. End view of same spine. Nat. size. 



15. Small piece of primary spine, near middle, x 10. 

 IG. Siibambital primary spine. Nat. size. 



17. Subambital primary spine. Nat. size. 



18. End view of same spine. Nat. size. 



19. Actinal primary spine. Nat. size. 



20. Smallest actinal primary spine. Nat. size. 



21. 22. Interambulacral secondary spines, x 11. 

 2.3. Ambulacral secondary spine, x 11. 



24. Actinal secondary spine, x 11. 



25. Actinostomal miliary. x 11. 



26. Calcareous particles from pedicels, x 156. 



27. Calcareous particles from pedicels of another individual, x 300. 



