PLATE LXV. 
Hederella Canadensis. 
Page 277. 
Fig. 1. A frond, natural size, showing the form and mode of growth. 
Fig. 2. An enlargement, showing an unusually compact growth. (X 6.) 
Fig. 3. A still further enlargement of a compact growth, showing more distinctly the form of the cell 
apertures. (X 12.) 
Fig. 4. An enlargement, showing distant cell tubes. (X 12.) 
Fig. 5. An enlargement, showing the cell tubes parallel to, and in contact with the main axis. (X 3.) 
Fig. 6. An enlargement, showing distant, sharply annulated cell tubes. (X 6.) 
Fig. 7. An enlargement, showing alternating cell tubes in contact with the main axis. (X 3.) 
Fig. 8. An enlargement, showing the usual mode of growth. (X 3.) 
Fig. 14. An enlargement, showing the transverse wrinkles and striations of the cell tubes and main axis. 
(X 3.) 
Hamilton group. York, Livingston county, N. Y. 
Hederella filiformis. 
Page 278. 
A frond, natural size, showing the form and mode of growth. 
An enlargement, showing strongly annulated cell tubes. (X 6.) 
An enlargement, showing the form of the cell tubes and mode of growth. (X 2.) 
Hamilton group. York, Livingston county, N. Y. 
Hederella cirrhosa. 
Page 277. 
A frond, natural size. 
An enlargement of tig. 12, showing more distinctly the form of the cell tubes and mode of growth. 
(X 6.) 
Hamilton group. West Bloomfield, N. Y. 
Hederella magna. 
Page 280. 
Fig. 15. An enlargement, showing the form and mode of growth of the cell tubes, the annulations and tine 
longitudinal striations. (X 6.) 
Hamilton group. York, Livingston county, N. Y. 
Hederella Canadensis. 
Page 277. 
Fig. 16. An enlargement of a frond. (X 3.) 
Upper Helderberg group. Falls of the Ohio river. 
Fig. 12. 
Fig. 13. 
Fig. 9. 
Fig. 10. 
Fig. 11. 
