PLATE XVIII. 



Figure 1. Trochocyathus Btjrnesi, J. Haime. Side view of the eorallunij natural size. 



2. The base, slightly enlarged. 



3. A side view of the eostsej magnified. 



4. The ornamentation of the septa, magnified. 



5. A young coral, the epitheca magnified. 



6. The costse and hase of a younger coral, magnified. 



7. Blanfordia nummipormiSj Duncan. The calice, magnified. 



8. The base, magnified. 



9. Some septa, magnified. 



10. IsastrjEa punctata, Duncan. The corallum from above, natural size. 



11. The base, magnified. 



12. Caliees, magnified. 



13. Side view of the corallum. 



14. Khabdophyllia Nariensis, Duncan. The corallum, natural size. 



15. A transverse section, magnified. 



16. Costse, magnified. 



17. Calamophyllia elongata, Dtmcan. Corallites, natural size. 

 17 o. A long coraUite. 



18. Outlines of caliees. 



19. A transverse section of a corallite, magnified. 



20. Costse, magnified. 



21. Stylophora contorta, Leymerie, sp. The branch, natural size. 



22. Caliees, magnified. 



