ON THE FOSSIL GENUS POROCYSTIS, CRAGIN. 



men, and the whole surface is covered with ridges and depressions. 

 The usual surface sculpturation consists of rather irregular 

 rows of approximately oval or circular depressions the centers of 



FIG. I. Medium-sized specimen, showing general form, foramen and radiating 

 canals. 



FIG. 2. Specimen with one short axis, diameter 12 by 19 mm. 

 FIG. 3. Medium-sized specimen, diameter 18 by iS mm. 

 FIGS. 4, 5. Different types of surface sculpturation. 

 FIG. 6. Ideal cross-section of test alone. 



which are in some specimens raised into papillae (Fig. 4). Some 

 have flat scar-like white areas with traces of the more prevalent 

 sculpturation (Fig. 5). Others have raised areas of the same 



