PLATE XVII. 



CORALS FROM THE MIDDI-K IJAS. 



FrG. 



1. MontlivaUia Vicforice, Duncan. Nat. size. A corallum, with a constriction near 



the calice. (P. 63.) 



2. A magnified view of some septal (external) ends, with eiidotheca, simulating costae 



and exotheca. The epitheca is shown covering these structures. 



3. A specimen with a large calice. 



4. A calice slightly magnified. The rudiuieutary septa are shown as faint white Hues 



close to the thin margin. 



5. Diagram of the septa. 



6. Slightly magnified view of the thin epithecal wall and the curved eudotheca. 



8. >• Different forms of the species. 

 9.) 

 10. A septum, magnified. 



