TABLE OF CONTEXTS, PP. 



Page. 



Preface by the authors, vii 



Introductory Chapter. 



Vespertine group, (Pocona formation, ) 3 



Its flora, 6 



Umbral shale group, (Mauch Chunk formation, ) . . . 9 



Conglomerate group, (Potts ville formation, ) 10 



Its flora, 11 



Lower productive coal measures, 15 



Their flora, 16 



Horizon of the Kittanning coal bed, 17 



Lower barren measures, 19 



Their flora, 20 



Upper productive coal measures, 21 



Upper barren measures, 24 



Three general sections, 29 



Chapter 2. 



Description of Species. 



Equisetites, 33 



Calamites, 34 



Sphenophyllum, 36 



Annularia, 38 



Sphenopteris, 40 



Neuropteris, 46 



Odontopteris, 52 



Callipteris 54 



Callipteridium, 55 



Pecopteris, ' 61 



( V pp. ) 



