PLATE XXXIX. 



Figure 1. Cidaeis. sp. (page 250). The test^ natural size. 



2. A coronal plate and part of an ambulacrum, magnified. 



3. CcELOPLEURUs EQUis, Agassiz (page 251). The test, abactinal view. 



4. Side view of the test. 



5. Interradial plates; lower part of fourth and the whole of the fifth from the apex, 



magnified. 



6. Interradail plate with tubercles at the ambitus, magnified. 



7. Ambulacral triplet and tubercle (actinal surface), magnified. 



8. The apical disk, magnified. 



9. CcKLOPLEURUs Pratti, d^Archlac (page 254). The test, from above. 



10. Part of ambulacrum and interradium, at ambitus, magnified. 



11. Apical disk, magnified. 



12. Semi-diagram of the oblique interradial plates and of the direction of the ambulacral 



sutural lines, magnified. 



13. Clypeaster, sp. (page 257). Abactinal view. 



14. Actinal view. 



