PLATE XIX. 



Pigure 1. A small corallum of Thamnastr^a Balli^ Duncan. Natural size. 

 3. Some calices^ magnified. 



3. A long calice, magnified. 



4. LitharjEa nodtjlosa, Duncan. The coralj natural size. 



5. A calicCj magnified. 



6. Calamophyllia Indica^ Duncan. The corallum^ natural size, 



7. A transverse section of a corallite, magnified. 



8. PlesiastrjEA EocenicAj Duncan. A part of the calicular surface of the corallum, 



natural size. 



9. Calices, magnified. 



10. A diagram of a septum and palus. 



11. Hydnophoka Maliriensis, Duncan. A part of the corallum, natural size. 



12. A colline, magnified. 



