PLATE LXIII. 



Stictopora subcaeinata. 



Page 261. 

 Fig. 1 . A fragment, natnrtil size. 



Hamilton group. Bellona, Yates county, N. T. 



Fig. 2. An enlargement from a decidedly angular specimen, showing the form and arrangement of the 



cell apertures, and a single i-idge along the middle of the branch. (X 6.) 



Fig. 3. A still farther enlargement, showing more distinctly the character of the cell apertures. (X 18.) 



Fig. 4. An enlargement from another branch of the same frond, showing a more flattened foi-m, and a 



moi-e irregular disposition of the cell aiiertui-es. (X 6.) 



Hamilton giiiup. Darien Centre, Genesee county, N. Y. 



Pig. 5. An enlargement from another frond, showing several ranges of apertures separated by striationa 



or ridges. (X 6.) 



Fig. 6. A still further enlargement, showing more distinctly the longitudinal ridges and the character of 



.!, i'.rj  the cell apertures. (X 18.) ■: "n-'i 



Hamilton group. Bellona, Yates county, iV. Y. 



^jyH 



ACROOENIA PROMFERA. 



Page 267. 



Fig. 7. A frond, natural size, showing the rootlets and manner of growth. 



Fig. 8. An enlargement from the preceding, showing inoi-e distinctly the character of the roots. (X 3.) 

 Fig. 9. An enlargement of the base of a branch, showing the conical, ti"uncated apex, and the striated 

 portion above. (X 6.) o ' 



Hamilton gi-oup. Vicinity of MutUmville, North Bristol tovmship, Ontario county, N. Y. 

 Fig. 10. An enlargement from near the base of a bi-anch from another frond, showing a different character 



of striation from the i>i*eceding. (X •>•) 

 Fig. 11. A still further enlargement from near the margin, showing the characterof the striation. (X 18.) 



Hamilton group. One milenirrtli of Pavilion Village, (renesee county, N. Y. 

 Fig. 12. An enlargement, showing the conirally ti-uncated base, Btriated longitudinal ridges, with ranges 

 of cell apertures between them. (X !>•) 



Hamilton group. Near Lodi Landing, Stneca lake, N. Y. 

 Fig. 13. An enlargement, showing the form and arrangement of the denticulated cell apertures, and the 

 longitudinal ridges. (X 6.) 



Hamilton group. Daritn Cetitre, Oenesee county, N. Y. '^ ' ■^' ' 



Fig. 14. An enlargement, showing pi-ominent denticnlations which have the appearance of circular cell 

 ajiertures. (X 6.) 



Hamilton gi*oup. EighteeTi-mile-creek, Erie county, N. Y. 

 Pig. 15. Enlargements of transvei>e sections from different portions of a branch, o, near the apex, b, a 

 little above, c, from the flattened (lai-t of the branch. 



Hamilton group. Vicinity of Muttonmlle, North Bristol tottmship, Ontario county, N. Y. 



Stictopora pekmakginata. 



Page 268, 

 Fig. 16. An enlargement, showing the form and arrangement of the cell apertures. (X 18.) 

 Hamilton group. West Hamburg, Erie county, N. Y. 



Stictopora bifurcata. 



Page 2S4. 

 Fig. 17. An enlargement, showing the mode of growth, the form and arrangement of the cell apertures, 

 and the longitudinal nodose ridges. (X 6.) 



Hamilton group. Near MuttonvUU, North Bristol totunship, Ontario county, N. Y. 



