PLATE XV. 



CORALS FROM THE LOWER LIAS. 



Fig. 



1. The upper calicular surface of Montlivaltia radiata, Duncan. (P. 61.) 



2. The under surface. 



3. A side view of the corallum, showing the central depression of the base. 



4. The calice, magnified, showing the quaternary arrangement of the septa. 



5. The base, magnified, showing the pellucid epitheca and the costse. 



6. The corallum oi Montlivaltia patifJa, Duncan. (P. 56). 



7. The calice, magnified, 



8. Part of the wall and one of the septa, magnified, showing the direction of the teeth. 



9. A very young Montlivaltia, of an unknown species. The calice magnified (P. 52.) 



10. A cornute variety of Montlivaltia mucronata, Duncan. (P. 60.) 



11. One of its septa, magnified. 



12. A portion of the external surface of the type of Montlivaltia mucronata, Duncan, 



showing the dichotomous longitudinal bundles of costae, magnified. 



13. A conical variety of Montlivaltia viucronata, Duncan. 



15. A section, magnified, of Montlivaltia Muperti, Duncan. 



16. A large and unusual shape of Montlivaltia ru(/osa, Wright. 



17. A side view of its dentate septa. 



14. A dentate process, magnified, showing the ornamentation. 



18. The corallum of /s«-$/r«« /(2/ww«fl^^c/roz"6?ra, Duncan. (P. 65.) 



19. Its septa, magnified. 



20. The corallum of Isastraa Tomesii, Duncan. (P. 46.) 



