THE STORY OF OUR ROCK FOUNDATION 



53 



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

 All plants except e. a, Alethopteris amhigua Lesqx.; b, Neuropteris vermiciilaris 

 Lesqx.; c, a horsetail, Annularia stellata Schl.; d, Sphenophyllum marginatum 

 Brougn.; e, a crustacean, Acanthotelson stimpsoni M. & W.; /, Palmalopteris furcala 

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



