Plate 100. 

 1-3. Genocidaris apoda A. Ag. and CI. 



1. Side view. X 5. 



2. Part of actinostoine and l)ase of corona. X 9. 



3. Abactinal system. X 7. 



4-6. Prionechinus ruber A. Ag. and CI. 



4. Side view. X 5. 



5. Part of actinostoine and base of corona. X 8. 



6. Abactinal .system. X 7. 



