Plate IIIB 



Fip. 1. Crawfish chimney at Station I, Charleston, 111. Probably formed by Cambann' grua'/is or 

 diogenes. (Photograph by T. L,. Hankinson.) 



Fig'. 2. General view at Station I. cf, showing numerous crawfish chimneys, probably formed by 

 Camharjis gracilis or diogefics. (Photograph by T. L. Hankinson.) 



