Plate XXXIII Continued. 



PAGE. 

 Fig. 6. NlCHOLSONELLA CUMTTLATA Ulr 423 



6. A fragment showing the usual external features of the species It is 



hollow and consists of several layers. Natural size. 

 6 a. Surface of same, xLJ, More perfect examples recently obtained show 



that the interspaces between the zooecia apertures are minutely granu- 



lose. 



6 b. Tangential section, x!8. 

 6 c. Vertical section representing part of a layer, much thicker than usual. 



x!8. 



Cincinnati.~group, Wilmington, 111. 



Illinois State Museum. 



-ill 







