Plate 101. 

 1-3. Prionechinus depressus A. Ag. and CI. 



1. Side view of denuded test. X 5. 



2. Part of actinostome and base of corona. X 10. 



3. Abaetinal system. X 7. 



4-6. Prionechinus sculptus A. Ap. and CI. 



4. Side view of denuded test. X 5. 



5. Part of actinostome and base of corona. X 10. 

 C. Abaetinal system. X 10. 



