Plate 95. 



Figs. 1-9. t^niUfhid jiiiixi. new species (p. 470). 



1. Fragmeuts of tlic boUow, siibeylindrieal zoariiim, natural size. 



2. A bifiii-catiug zoariuni, X 20. A frequent occurrence, in wUich tlie avicularia are 



salient and replace the tremopores. 



3. Another specimen, X 20, with several ovicelled zooecia. 



4. An e.xaniple, X 20, with thick peristome and quite prominent avicularia and rare 



areolae. 



5. Branching zoarium, X 20, exhibiting a frequent aspect of the species. Some of the 



avicularia preserve the pivot. 

 G. Surface of fragment, X 20, showing the oblique semilunar ajiertura at the bottom 

 of the peristomie. 



7. Zooecia with median avieularium preservetl, X 20. One of the zooecia Is calcified. 



8. Longitudinal .section of a branch, X 20. The dorsal of the zooecia is shown in the 



middle, and on each side is a section illustrating the internal structure. 



9. Cross section of a branch, X 10. 



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

 ville, Alabama. 



Cat. No. 64307, U.S.N.M. 

 Figs. 10-21. PorceUa crassoparics. new si)ecies (p. 400). 



10. Four examples of the hollow, cylindrical, unilamellar zoarium, natural size. 



11. Ovicelled zooecia, X 20. 



12. Young zooecia, X 20. some of which have raised margins. The avicularia are quite 



visible. 



13. Old zooecia, X 20, exhibiting the usual aspect, with the avicularia almost Invisible. 



14. Surface of an old zoarium, X 20. The avicularia are little visible and the zooecia 



appear larger. 

 15. 16. Two longitudinal sections, X 10. Both the internal .structure of the zooecia and 

 the character of the dorsal are shown. 



17. Sketch of a longitudinal section through several zooecia, X 20. 



ap, aperttira ; ol, olocyst ; /)/, peristomie: pic, peristomice; 1r, tremocyst; tii, tubule; 

 ;, zooecium. 



18. Interior of zooecial frontal, X 20, exhibiting thinness of zooecial lateral walls. 



19. Interior of zooecial frontal, X 20. illustrating the small pores perforating the olocyst. 



20. Tangential thin section, X 100. The section cuts the tremocyst in the upper half 



and the olocyst in the lower. 



21. Transverse section. X 20, showing the thickness of the frontal. 



Vicksburgian (Glendon member of Marianna limestone) : West bank of Conecuh 

 River, Escambia County, Alabama. 

 Cat. No. 64308, U.S.N.SI. 

 96 



