PLATE XIV. 



COSCINIUM. 



(Page 537.) 



COSCINIUM feTRIATURUM, Hall. 



Fig. 1. A specimen, natural size. 



Upper Helderberg group. Stafford, JSF. Y. 



CERAMELLA. - 



(Page 527.) * 



Cera-mella scidacea, Hall. 

 Fig. 2. A weathered specimen, natural size. 

 Fig. 3. An enlargement from the preceding. x6. 

 Fig. 4. A fragment of a well-preserved specimen, natural size. 

 Fig. 5. An enlargement from the preceding. x6. 

 Fig. 6. A vertical section, showing the form of the cell tubes and 

 their manner of growth. x6. 

 Hamilton group . New York, 



COSCINELLA. 



(Page 534.) 



COSCINELLA ELEGANTULA, Hall. 



Fig. 7. A frond, natural size. 



Fig. 8. A portion of the preceding figure. x6. 



Fig. 9. A transverse section of the portion of the frond between 



adjacent cell apertures. x6. 

 Fig. 10. A vertical section, showing' the form and manner of growth 

 of the cell tubes and the intercellular vesiculose tissue. x6. 

 Fig. 11. An enlargement of the mesotheca. x6. 

 Fig. 12. An enlargement of one of the cell apertures. x72. 

 Hamilton group. Widder, Ontario. 



