THE STORY OF OUR ROCK FOUNDATION 



53 



FIG. 36. Fossils from the Pennsylvanian coal measures, Mazon Creek, 111. 

 All plants except e. a, Aldhopteris ambigua Lesqx.; b, Ncuropteris vermicnlaris 

 Lesqx.; c t a horsetail, Annular ia stellata Schl.; d, Sphenophyllum marginatum 

 Brougn.; e, a crustacean, Acanthotelson stimpsoni M. & W.; /, Palmatopteris fur cata 

 Potonid.; g, bark of Sigillaria sillimani Brougn. Plant photos by P. O. Sedgwick. 



