PLATE LXIV. 



LlCHENALIA CULTEJXATA. 



I'&ge -iiyi. 



Fi(f. 1. An enlargement of one of the monticules, showing the form and disposition of the cell apertures; 



usually the cell apertui-es are trilobate. (X 6-) 

 Fi(f. 2. A still farther enlargement of the center of the monticule, showing the ridg'es extending fi-om the 

 center to the adjacent cell apertures. (X 18.) 



Hamilton) gi-oup. FaU-brmk, four miles east of Caiuindaigua lake, on the old Geneva 

 mod, Ontario county, N. Y. 



BOTRYLLOPORA SOCIALIS. 



I'age 28i. 



Fig. 3. An enlargement, showing the general appearance of a specimen, the arrangement of the cell 



ai>ertui-es, and the bullae of the surface. (X 6.) 

 Fig. 4. An enbii-genient of a vertical section, showing the form and mode of growth of the cell tubes, 

 an<l the intercellular vesicles. (X 6.) 



Hamilton group. Y(yrk, Livingston county, N. T. 



Ceramella scidacea. 



I'age 240. 

 Fig. 5. A fragment of a frond, natural size, showing the foi-m and arrangement of the maculae. 

 Fig. ti. An enlargement, showing one of the miiculas, and the form and disposition of the cell apertures. 

 (Xti.) 



Hamilton group. SIturger's Cflen, Norton's Laiiding, Cayuga lake, N. Y. 

 Fig. 7. A fragment of a frond, natural size, showing narrow, elongate maculae ; the surface is macerated. 

 Fig. 8. An enlargement from the preceding, showing one of the maculae, and the appearance of the 

 macerated surface. 



Hamilton group. Near AUxandtr, Qenesee county, N. Y. 



COSCINELLA ELEGANTULA. 



I'agc 239. 

 Fig. 9. A part of a frond, natural size, showing the general appeai-ance, the radiation, and the form and 



disposition of the fenestrules or pei-forations. 

 Fig. 10. An enlargement from the preceding, showing the foi'm and di8j)Osition of the cell apertures, the 



interme<liate pits, and the pits surrounding the fenestrules. (X 6.) 

 Fig. U. An enlargement of a vertical section, showing the form and manner of growth of the cell tubes, 



and the intei-cellular vesicles. (X 6.) 

 Fig. 12. An enlargement of a transvei'se section, showing the form of the frond between the fenestrules. 



(X ti.) 



Hamilton group. Widder, Ontario, Canada. 



COSCINIUM STRIATUM. 



I'age 2.38. 



Fig. 13. A part of a frond, natural size, showing the general appeai'ance, and the fonn and disposition 



of the fenestniles. 

 Fig. 14. An enlargement from the preceding, showing the disposition of the cell apertures, the inter- 

 mediate stiiations, and the non-celluliferous space bordering the fenesti'ules. (X 6.) 

 Fig. Ifi. A still fui-ther enlargement, showing circular cell apertures, slight, denticulated peristomes, 



and the intermediate no<ies and siriie. (X 18.) 

 Fig. IG. An eidargement from another portion of the same frond, showing oval cell apertures; the other 

 cbaractei-s being similar to those of the preceding figure. (X 18.) 

 Hamilton grou}>. West Williams, Ontario, Caiuula. 



