

CONTENTS 



Preface 5 



Introduction ' 7 



Acknowledgments 8 



Age relations of coal-balls containing Mazocarpon 8 



Illinois coal-ball horizons 10 



European coal-ball horizons 11 



Discussion 13 



Description of new material 14 



Mazocarpon Benson, ex Scott, 1909 14 



Mazocarpon oedipternum sp. nov 14 



Forma megalophorum, forma nov 15 



Forma microphoi^um, forma nov 15 



Morphologic features 16 



Comparison of M. oedipternum with other species of Mazocarpon 22 



Mazocarpon petty curense Benson 22 



Mazocarpon cashii 22 



Mazocarpon shorense 22 



Relation of Mazocarpon to affiliated groups of plants 25 



Peduncular steles of Sigillaria and Mazocarpon 27 



Relation of Mazocarpon and Bigillariostro'bus 28 



Specific relationships 3o 



Relation of Paleozoic lycopod groups 34 



Free-sporing character of Mazocarpon 34 



Mazocarpon and Lepidocarpon 35 



Mazocarpon and Spencerites 35 



Conclusion 36 



References 37 



[3 



