PLATE XXVI. 



Figure 1. Monticulastb^a insignis, Duncan. A part of the corallum, natural size. 



2. Some collines^ magnified. 



3. A longitudinal section, showing the columella and endotheca, magnified. 



4. MoNTicuLASTRiEA iNiEQUALis, Duucau. A part of the top of the corallum, natural size. 



5. MoNTicuLASTR^A soLtDioRj Duncan. A part of the upper portion of the coral, natural 



size. 



6. A coUine, magnified. 



7. Hydnophora eudis, Duncan. A part of the upper surface of the coral, natural size. 



8. Some coUineSj slightly magnified. 



9. Hydnophora plana, Duncan. A part of the calicular surface. 



10. Collines, slightly magnified. 



11. Hydnophora Dan^, Duncan. Some collines, magnified. 



12. Hydnophora hemisph^kica, Duncan. Collines, magnified. 



13. Cycloseris magnifica, Duncan. A calice, slightly magnified. 



