Plate OG. 

 Figs. 1-9. Siiiittiiid rcticidoidcfi. new species (p. 467). 



1. Four fragments of the bilamellar zoariiim, natural size, sliowing variations in widtli. 



2. Surface of a broad zoarium, X 20, e.xliibiting tlie usual aspect of the .species. 



3. A well-preserved zoarium, with the ovicells and median avicularia well shown. The 



pores of the ovicell area are very small. 



4. A specimen, X 20, with intense pleurocystal calcification. 



5, 6. Two other examples, X 20, in which the intense calciflcatiou has left salient ridges 

 bounding the zooecia. 



7. A fragment, X 20, showing another aspect of the ovicelled zooecia. The pores of 



the ovicell are very large. 



8. Tangential thin section, X 100, at the level of the olocyst. 



9. Another tangential thin section, X 100, passing through the interareolar costules. 

 VicUsburgian ("Chinuiey rock" of Mariauna limestone) : One mile north of Monroe- 



ville, Alabama. 



Cat. No. 64309, U.S.N.M. 

 Fig. 10. riiulacteUa, crihrata, new species (p. 575). 



Surface of the inerusting type-specimen, X 20. 



Vicksburgian ("Chimney rock" of Mariauna limestone) : One mile north of Monroe- 

 ville, Alabama. 



Cat. No. 64310, U.S.N.M. 

 Fig. 11. CateniceUa siil)septcntiionaHs Cauu and Bassler, 1917 (p. 550). 

 The type-specimen, X 25. 



Vicksburgian (Mariauna limestone) : Salt Mountain, 5 miles south of Jackson, 

 Alabama. 



Cat. No. 62601, U.S.N.M. 

 Figs. 12-22. Retepora laciniosa, new species (p. 504). 



12. Fragments of the free, branching, noureticulated zoarium, natural size. 



13. View of the frontal. X 20. 



14. A young specimen, X 20, showing the lateral rimule-spiramen. 



15. View of the dorsal surface, X 20. 



16. A smooth dorsal, X 20. 



17. Dorsal surface, X 20, with tubular projections developed. 



18. Frontal of specimen, X 20, showing ovicells. 



19. Frontal of another example. X 20, with frontal avicularia. 



20. Another view of the frontal, X 20, with the labial avicularium much developed. 



21. A frequently bifurcated specimen. X 20. The rimule-spiramen and frontal tuberosity 



are exhibited. 



22. An example, X 20. in which large frontal avicularia are present. 



A'icksburglan (Marianua limestone) : One mile north of Monroeville, Alabama (tigs. 15. 

 21, 22) ; west bank of Conecuh River. Escambia County, Alabama (figs. 13, 14, 

 17, 19, 20), and Salt Mountain, 5 miles south of Jackson, Alabama (figs. 16, 18). 

 Cat. Nos. 64311, 64312, 64313, U.S.N.M. 



55899— 20— Bull. 106. Vol.2 13 97 



