Plate 2:1. 



Figs. 1-3. Pordla (Palmicellaria) convoluta Ulrich and Bassler, IIKM. (p. 150.) 



1. The convoluted, bifoliate zoarium. natural size. 



2. Zooecia, X 20, showing the prominent mucro and the aviculariuni. 



3. Surface of another fragment, X 20, with several closed zooecia. 

 iriocene (Calvert formation): Reeds, Maryland. 



Fic. 4. Porella {Palmicellaria) punctata Ulrich and Bassler, 1904. (p. 1.50.) 



The bifoliate type specimen, X 20. 



Miocene (Calvert foi'mation): Reeds, Maryland. 

 Figs. 5-10. Porella rercrsa Ulrich and Bassler, 1904. (p. 148.) 



5. Portion of the incrusting zoarium, X 20, showing the zooecia with thin raised borders. 



6. Another zoarium, X 20, with ovicelled zooecia. 



7. Drawing showing usual aspect of the ovicelled and unovicelled zooecia, X 28.5. 



8. Zooecia of a specimen with ovicells, X 28.5. 



9. Several zooecia, X 28.5, with the boundaries well defined. 

 Miocene (St. Mary's formation): Cove Point, Maryland. 



10. A view of the zooecial walls after abrasion of the frontal, X 20. 

 Miocene: Kuhns, Carteret County, North Carolina. 



Figs. 11-17. Retepora doverensis Ulrich and Bassler, 1904. (p. 152) 

 11-13. Three specimens, natural size. 



14. Portion of a type specimen, X 20, showing the fissured ovicell and the wide irregular rimule 

 gpiramen. 



15. Noncelluliferous side of a zoarium, X 20. 



IG. One of the original types, X S, mth ovicelled zooecia. 



17. Drawing of several zooecia, X 30. 



Miocene (Choptank formation): Dover Bridge, Maryland. 



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