PLATE XXXIII. 



Figure 1. Rhynchopygus CalderIj d'Archiac and Haime, sp. (page 184). Abaetinal view of the 

 test, natural size. 

 1 a. Ambulacral petal, magnified. 



2. Longitudinal view of the same test, natural size. 



3. The same test seen from behind, natural size. 



4. Actinal view of another test, natural size. 



5. The peristome and surrounding portions, magnified. 



6. Abaetinal view of an abnormal specimen, in which the odd anterior ambulacrum is 



aborted, natural size. 



7. Rhynchopygus pygm^eus, Duncan and Sladen (page 187). Abaetinal view of the test, 



natural size. 



8. Actinal view of the test, natural size. 



9. Longitudinal profile of the same test, natural size. 



10. The same test seen from behind, natural size. 



11. Abaetinal view of the test of a large, widely expanded, high form, natural size. 



12. Longitudinal profile of the same test as fig. 11, natural size. 



13. Abaetinal view of the test of another large form, natural size. 



14. Longitudinal profile of the same test as fig, 13, natural size. 



15. Abaetinal view of the test of a flat, depressed variety, natural size. 



16. Longitudinal profile of the same test as fig. 15, natural size. 



17. Cassidtjltjs subinvaginatus, Duncan and Sladen (page 182). Abaetinal view of the 



test, natural size. 



18. Actinal view of the test, natural size. 



19. Longitudinal profile of the test, natural size. 



20. The test seen from behind, natural size. 



