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Figs. 1, 2. CYPHOTRYPA CORRUGATA (Weller) 269 



1. Vertical section, showing the characteristic crenulated walls and 



the distribution of diaphragms. X 20. 



2. Tangential section illustrating the range in size of the macular and 



intermacular zorecia. X 20. 



Decker Ferry formation, New Jersey. 



Figs. 3, 4. DIPLOSTEXOPORA SILURIANA (Weller) 277 



3. A vertical section illustrating the bifoliate method of growth and 



the characteristic perforated diaphragms. X 20. 



4. Several zocecial tubes of the same section. X 35. 



Decker Ferry formation, New Jersey. 



Figs. 5-8. MONOTRYPA SPH.ERICA (Hall) 278 



5. Side view of a zoarium, natural size. 



6. A vertical fracture, natural size. 



7. An enlargement of the celluliferous surface. 



8. Vertical section illustrating the distribution of the diaphragms. 



X 4. 

 New Scotland formation, New York. 



Figs. 9-11. FENESTELLA ? IDALIA Hall 281 



9. A funnel-shaped frond, natural size. 



10. An enlargement of the non-celluliferous face of the same. 



11. An enlargement of another specimen with stouter branches. 



New Scotland formation, New York. 



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