PLATE XXI. 

 CHILOTRYPA. 



(Page 554.) 

 Chilotrypa ostiolata, Hall. 



Fig. 1. Fragments of zoaria, natural size. 



Fig. 2. An enlargement of a thin section showing the axial tube, 

 the cell tubes and the intercellular vesicles. x9. 

 Niagara group. Lockport, ISF. Y, 



COELOCAULia 



(Page 554.) 



CCELOCAULIS VENUSTA, Hall. 



Fig. 3. A fragment, natural size. 

 Fig. 4. An enlargement of the preceding. x6. 



Fig. 5. An enlargement of a specimen fractured so as to show the 

 cells, the intercellular vesicles and the epitheca. x9. 

 Lower Helderberg group. JVear Clarksville, If. Y. 



FISTULIPORINA. 



(Page 555.) 



FiSTULIPORINA MICBOPORA, Hall. 



Fig, 6. An enlargement showing the manner of growth of the 

 frond, the form and arrangement of the cell apertures and 

 mesopores. 

 Hamilton group, ^rie county, N'. Y, 



Figs. 7-10. Enlargements showing the internal structure of the fol- 

 lowing species: 

 Fig. 9. JFl stellata ; Fig. 10, F. variopora, 



FiSTULIPOEINA DIGITATA, Hall. 



Fig. 11. An enlargement of a frond incrusting a Cyathophylloid 

 coral, showing the manner of growth and the form and 

 arrangement of the cell apertures and mesopores. x6. 

 Hamilton group. West Samburghy JV. Y. 



FiSTULIPOEINA MULTICDLEATA, Hall. 



Fig. 12. An enlargement showing the form and disposition of the 

 cell apertures and the numerous nodes on the peristomes 

 and walls of mesopores. xl8. 

 Hamilton group. Darien Center, iVi Y, 



660 



