418 New York State Museum 



Literature. For the general discussion of the De- 

 vonian period the same textbooks are recommended as 

 for the previous chapters; also Schuchert ('10), Ulrich 

 ('11), Ulrich and Schuchert ('02), Willis and Salisbury 

 ('10) and Weller ('10). 



For the New York formations Miller ('24) is recom- 

 mended for a general survey and many references. Among 

 other State Museum publications are Chadwick ('24), 

 Clarke ('96, '00, '01a, b, '03a, '08-'09), Clarke and Lu- 

 ther ('04, '05a, b, '08), Darton ('94a, b, c), Grabau ('98, 

 '03, '06), Hartnagel ('12), Hopkins ('14), Loomis ('03), 

 Luther ('06a, b, '09, '11, '14), Prosser ('96, '99a, b, '00), 

 Ruedemann ('30), Shimer ('05). Articles on New York 

 formations printed elsewhere have been written by Chad- 

 wick ('08), Cleland ('03), Cooper ('30), Dale ('04), 

 Fairchild ('28), Grabau ('17, '19), Prosser ('03), Schu- 

 chert ('00), Williams ('06, '07), Williams and Kindle 

 ('05) and Williams, Tarr and Kindle ('09). 



Mississippian, Pennsylvanian, Permian Periods 

 The term Carboniferous was formerly applied to the 

 system of rocks above the Devonian from the quantities 

 of coal (carbon) occurring in the rocks of that period. 

 The system then included the Lower Carboniferous (Mis- 

 sissippian), the Upper Carboniferous (Pennsylvanian) 

 and the Permian, which are now regarded as separate 

 systems. Some geologists believe that there is evidence 

 to show that there is no true Permian in this country, 

 that the Lower Permian beds belong with the Upper Car- 

 boniferous or Pennsylvanian and that the Upper Permian 

 belongs with the following Mesozoic era. The name Mis- 

 sissippian (Winchell, 70) was applied because of the 

 marked development of these rocks in the Mississippi 



