PLATE LVII. 



Spines of CiDARiDiE (pages 373, 374). 



Figure 1. Front view of a tall spinulose radiole, witli a shallow cup at the top surrounded by 

 stout spinules, natural size. 



2. Back view of the same, natural size. 



3. Front view of a more stunted-and flatter radiole, with close and short spinules, natural 



size. 



4. Back view of the same. 



5. Side view, showing the cup, natural size. 



6. 8, 11, and 12. Front views of radioles of the same type, natural size. 



7. 9, 13. Back views of the same, natural size. 



10. Back view of a radiole and its base ; the latter is magnified. 

 14. A small radiole, natural size. 



