312 



PLATE I 



Ceramoporella ingenus Ulrich and Bassler. 



1. Vertical section x 20. 



2. A portion of the surface x 10. 



3. Tangential section x 20. 



Pierce limestone, Miu'freesboro, Tenn. 



Ceramoporella grandis Ulrich and Bassler. 



4 and 5. Tangential sections x 20, showing the proiminent lunaria' 

 6. A portion of the surface x 10. 



Pierce limestone, Murfreesboro, Tenn. 



