PLATE I. 



corals from the great oolite and from the inferior oolite. 



Fig. 



1 . Thecosmilia obtusa, d'Orb. The corallum. (Great Oolite.) (P. 14.) 



2. The upper margin of a septum, magnified. 



3. The cahcular surface, magnified. 



4. Costse, magnified, and epitheca. 



5. Montlivaltia Holli, Duncan. (Inferior OoUte.) (Page 16.) 



6. The calicular sm-face, magnified. 



7. The caUce, magnified. 



8. A corallum with calicular gemmation. 



9. Cyathophora inslgnis, Duncan. (Great Oolite.) (Page 14.) 



10. A calice, magnified. 



11. Three calices, slightly magnified. 



13. Montlivaltia Painswicki, Duncan. (Inferior Oolite.) (Page 17.) 



