FLATE XXIX— Con tinaed. 



Spirifeu nobilis, Banande. 



Vig. 16. A section along the longitudinal axis looking into one of the coils. The apparent process on the 

 second volution is casual. 



Niagara group. Near Chicago, Illinois. 



Genus AMBOCOiLIA, Hall 



Page M. 



Amboccelia umbonata, Conrad. 



Fig. 15. A preparation, showing the loosely coiled spirals with but few volutions. X 6. (c.) 

 Hamilton group. Western New York. 



Genus SPIRIFERINA, d'Orbigny. 



Page 51. 



Spiriferina Kentuckiensis, Shiimard. 



Fig. 17. A specimen whose brachidium is preserved in pyi-ite ; showing the united jugal processes which 

 form a continuous loop. The pedicle-valve is on the lower side of the figure. 

 Coal Measures. Vinton county, Ohio. 



