PLATE LIIT. 



Fin. 



1-3. Retepora Beaniana, p. 391 ; uat. size. 



4. , zooecia. 



5. , dorsal surface. 



G, 7. Retepora Couchii, p. 395 ; nat. size. 



8, 10. , zocEcia. 



9. , dorsal surface. 



11. , elongate aviculariura. 



