394 



sufficiently good to enable the species to be reliably deter- 

 mined. 



Calamites suckowi Brongnt. 

 Annularia sphenophylloides Zenker. 

 Annularia stellata Schlotheim sp. 

 Annularia latifoila Dawson sp. 

 Stigmaria ficoides 

 Adiantides ohtusa Dawson sp. 

 Rhacopetris hiisseawa Steer 

 Sphenopteris marginata Dawson 

 Oligocarpia splendens Dawson sp. 

 Sphenopteris valida Dawson sp. 

 Pecopteris pliimosa Artis. 

 Diplothmema suhjurcatus Dawson sp. 

 Alethopteris lonchitica Schlotheim sp. 

 Megalopteris dawsoni Hartt sp. 

 Nenropteris heterophylla Brongnt. 

 Neuropteris gigantea Sternberg 

 Sporangites acuminata Dawson 

 Pteriopermostrahus hifiircatus Stopes 

 Dicranophyllum glahrum Dawson sp. 

 Whittleseya dawsoniana D. White 

 Whittleseya concinna Matthew 

 Cordaites riihhii Dawson 

 Cordaites principalis German sp. 

 Dadoxylon ouangondianum Dawson 

 Cordaianthus devonicus Dawson sp. 

 Cardiocarpon ohliquum Dawson 

 Cardiocarpon baileyi Dawson 

 Cardiocarpon cornutum Dawson 

 Cardiocarpon crampii Hartt. 



Every species of importance is a typical Carboniferous 

 one. By David White the plant-bearing Fern Ledges have 

 been correlated with the Pottsville ; by Kidston they have 

 been correlated with the European Lower Coal Measures. 

 By White the upper part of the Pottsville is considered 

 to be very nearly contemporaneous with the Lower Coal 

 Measures of Europe. But it would appear that the Fern 

 Ledges represent a somewhat higher zone than that 

 assigned by White. 



If a comparison be made between the Fern Ledges and 

 Westphalian floras it is at once evident how remarkably 



