Plate 53. 



1-7. Coelopleurus maculatus A. Ag. and CI. 



1. Aetinal view of denuded test. X 2. 



2. Abactinal view of same. X 2. 



3. Odd anterior ambulacrum. X 2. 



4. Left posterior interambulacrum. X 2. 



5. Primary spine, seen from side. X 1.5. 



6. Base of primary spine, seen from above. X 4. 



7. Tip of primary spine, seen from above. X 4. 



8, 9. Coelopleurus Maillardi A. Ag. 



8. Primary spine of type specimen from Bourbon. X 1.5. 



9. Primary spine of young specimen from Kei Islands. X 1.5. 



10. Coelopleurus longicollis A. Ag. and CI. 



10. Primary spine of type specimen, x 1-5. 



11. Coelopleurus floridanus A. Ag. 



11. Primary spine. X 1.5. 



