22 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 500 



Megalopteris has "been reported from only a few localities: 



Wyoming Hills, Iowa - Noe*, 1925 



Port Byron, Illinois - Lesquereux, 1880 



Brown County, Illinois - this report 



Greene County, Indiana - Canright, 1959; Wood, 1963 



Putnam County, Indiana - oral communication, C. A. Arnold, 



collected in 1936 

 Rushville, Ohio - Andrews, 1875; Cross, 1962 

 Grand Ledge, Michigan - Arnold, 193^ 

 Saginaw, Michigan - Arnold, 193^- 

 Logan County, W. Va. - Arnold, 19^7 

 New River, W. Va. - D. White, 1895 

 St. John, New Brunswick, Canada - Dawson, 1871; Stopes, 



Pictou, New Brunswick, Canada - Bell, 19^0 



In nearly half of these localities Megalopteris occurs with a 

 peculiar flora which is distinctly different from a normal coal basin 

 flora and probably lived on rather dry soils. 



Megalopteris has never been found with any fructifications at- 

 tached. Any conclusion about its systematic position must be based on 

 indirect evidence. It is here included in the Pteridosperms because 

 the leaf morphology compares with such well-established pteridosperm 

 genera as Alethopteris and Taeniopteris . Florin (1933) showed that the 

 structure of the epidermis and stomata of Megalopteris was very similar 

 to that of Neuropteris and other pteridosperms . 



Megalopteris dawsoni (Hartt) Andrews 

 Text fig. 8A; pi. 6, fig. 3 



Synonymy 



I865 Neuropteris sp. nov. , Hartt in_: Bailey, p. 137 



1868 Neuropteris dawsoni, Hartt in: Dawson, p. 551, 

 fig. 133 



1871 Neuropteris (Megalopteris) dawsoni, Hartt in : 

 Dawson, p. 51, pi. 7, figs. 191-19^ 



1875 Megalopteris dawsoni, Andrews, p. Ul5 



1875 Megalopteris hartti , Andrews, p. hl6, pi. h6 9 

 figs. 1 and la 



Text fig. 8 - Fossil plants from the Spencer Farm Flora. A-P, venation pattern in 

 Megaloptoris , A- M. dawsoni, B- M, ovata, C- Lesleya cheimarosa, D- M. fasciculata, 

 EC, reconstruction of a leaf* of M. ovata, V, drawing of the holotype of Lesleya 

 cheimarosa showing the variation in the shape of the lateral veins in different 

 parts of the leaf. Bar scales are 5 min long. 



