Plate 88. 



Figs. 1-7. Didymosella c7-asm Canu and Basslei-, 1917 (p. 416). 



1. Three of tlie unilamellar zonria wbich by growth aboiil aljjae have assumed a 



cylindrical form; natural size. 



2. Surface of a zoarium, X 20. showing the bottle shaped zooecia with treraocystal 



frontal, two large pores opeaiug into the zooeeium aud the triangular marginal 

 avicularium. 



3. Basal side of a zoarium, X 20, e.xhihiting the characteristic markings. 



4. Sketch of longitudinal section, X 25, illustrating the structure of this species. 



ui>. apertura; av, avicularian cavity; /, veiy If.rge frontal pore; p, smaller pores 

 (tremopores) ; z, zooeeium. 



5. Tangential thin section, X 100. The aperture with the two large pores just below 



it, the tremopores aud finally the very large avicularian cavity are visible. 



6. View of the interior of the zooecial frontal. X 20, illustrating the very large 



avlcularia. 



7. Longitudinal edge view of zooecia, X 20, showing the same features as in figure 4. 

 Vicksburgiau (Glendon member of Mariauua limestone) : ^Yest bank of Conecuh 



River, Escambia Coimty, Alabama. 

 Cat. No. 62592, U.S.N.M. 

 Figs. S-16. Ci/clicopora sponpiopsis De Gregorio, 1899 (p. 426). 



8 Three small specimens, natural size, of the hollow stemmed uuilamellar zoarium. 

 9. Transverse section, X 20, showing the thick walls of both the frontal and the 

 tubules. 



10. An old example, with a calcified zooeeium. X 20. 



11. Zoarium, with some ovicelled zooecia and triangular avicularia with pivot, X 20. 

 12 An example in which the zooecia develop one to four peristomial avicularia, X 20. 

 13. Tangential thin section, X 100. The large tremopores and the dark sinuous lines 



of Intersection with the olocyst are visible. 

 14 A zoarium. X 20, with the zooecia outlined by a prominent thread, 

 is! Another specimen, X 20, in which usually only one peristomial avicularium is 



developed. 

 16 Part of a zoarium, X 20, exhibiting five ovicelled zooecia. 



Vicksburgiau ("Chimney rock" of Slarianna limestone): 1 mile uorth of Monroe- 

 ville, Alabama. 



Cat. No. 64286, U.S.N.M. 

 Figs 17-19. Cyclicopora filifera, new species (p. 427). 



17. Surface of the incrusting zoarium, X 20, with ovicelled zooecia. Many of the 



ovicells are broken. The tremocyst is here replaced by a thick pleurocyst. 

 13 Several zooecia, X 20, of a specimen with well defined separating lines. 

 19. Well preserved example, X 20, with the tremopores visible and the apertura placeii 

 at the bottom of the peristomie. 

 Vicksburgiau (Marianna limestone): Near ClailMrne, Monroe County (figs. 17, 19 1, 

 and west bank of Conecuh River. Escambia County. Alabama (fig. 18). 

 Cat. Nos. 64287, 64288, U.S.N.M. 

 55899— 20— Bull. 106, Vol. 2 -12 89 



