Plate 12. 



1-17. Acanthocidaris hastigera A. Ag. and Clark. 



1. Tip of stalk of globiferous jiedicellaria, showing limb. x 156. 



2. IMost abactinal primary spine. Nat. size. 



3. Abactinal primary spine. Nat. size. 



4. Side view of ambital primary spine. Nut. size. 



5. Ambital primary spine. Nat. size. 



6. Subambital primary spine. Nat. size. 



7. Actinal primary spine. Nat. size. 



8. More actinal primary spine. Nat. size. 



9. Still more actinal primary spine. Nat. size. 



10. Most actinal primary spine. Nat. size. 



11, 12. Interambulacral secondary spines, x 11. 

 13,14. Ambnlacral secondary spines, x 11. 



15. Actinal view of actinal secondary spine. x 11. 



16. Side view of same spine, x 11. 



17. jMiliary. x 11. 



18-30. Anomocidaris tenuispina A. Ag. and Clark. 



18. Valve of pedicellaria. x 15G. 



19. Ambital primary spine. x 3. 



20. Actinal primary spine. x 3. 



21. Most actinal primary spine, x 3. 



22. 23. Interambnlacral secondary spine. x 11. 

 24. Actinal secondary spine. x 11. 



25-27. Auibulacral secondary spines. x 11. 



28, 29. Actinal arabulacral secondary spines, x 11. 



30. Miliary. x 11. 



