148 PROCEEDINGS OF THE NATIONAL MUSEUM. vol, 61. 



Figs. 8-13. Chilopora guernoni Haime, 1854 page 105. 



8. Zoarial fragments, natural size. 



9. An ovicelled frond, X 12. 



10. Fragment, X 12, preserving tubes with the lip-like projection only in the 



lower half. 



11. Frond, X 12, exhibiting the small ovicell. 



12. View, X 25, of tube with the characteristic terminal lip. 



13. Another portion of the surface, X 12, in which the lip is wanting. 

 Jurassic (Batlionian) : Occaignes (Orne), France. 



Pl^TE 17. 



Figs. 1-8. Ditaxia pai'vipora, new species page 103. 



1. Zoarial fragments, natural size. 



2. A fragment, X 6, with a narrow zoarial base. 



3. Another fragment, X 6, showing the median lamella at the extremity of 



the branch. 



4. Zoarial surface, X 25, illustrating the form of the zooecia and mesopores. 



5. Another surface, X 25, in which the distinction between the two kinds 



of tubes is not so apparent. 

 C. An example, X 12, illustrating the normal form of the ovicell with the 

 oeciostome at the center. 



7. Another example, X 12, with the ovicell partially covered by the adja- 



cent mesopores. 



8. A specimen, X 12, with small tubes. 



Cretaceous (Coniacian) : St. Paterne and Tours (Indre-et-Loire), France. 

 Figs. 9-13. Ditaxia anomalopora Goldfuss, 1827 page 101. 



9. Fragments of the bilamellar zoarium, natural size. 



10. Section of a branch, enlarged, showing the median lamella. 



11. Edge of a branch enlarged showing the crest representing the median 



lamella. 



12. Zoarial surface, enlarged (figs. 9-12, after Hagenow, 1851). 



13. Portion of the surface of young example X 12, showing slightly salient 



peristomes. 

 Cretaceous (Maastrichtian) : Maastricht, Holland. 

 Figs. 14-16. Chilopora cretacea, new species page 106. 



14. Portion of the zoarial surface X 25. The tubes have a salient lip. 



15. An ovicelled example, X 12. The ovicell is globular and placed on the 



edge. 



16. Another oviceUed example, X 12. The ovicell is broken showing its 



interior. 

 Cretaceous (Santonian) : Vendomg (Loire-et-Cher), France. 



PlATE 18. 



Figs. 1-4. Alveolaria semiovata Busk, 1859 page 111. 



1. Top view of the zoarium, natural size. 



2. Lateral view of zoarium, natural size, broken to show the structure. 



3. Two of the subcolonies, X 12, each with an ovicell. 



4. Edge view of zoarium, X 6, illustrating its formation by cupshaped 



subcolonies. 

 Pliocene (Plaisancian) : Sudbourne Church, Suffolk, England. 

 Figs. 5-9. Tretocycloecva sahaudica, new species page 110. 



5. The ramose zoarium, natural size. 



