86 H. D. Miser — Llanoria, the Paleozoic Land 



Mississippi Valley just before the beginning of Mississip- 

 pian time and during Osage time. 



T. C. Cliamberlin and E. D. Salisbury ,^^ on several 

 maps published in 1906, show land extending from the 

 Appalachians westward across the lower Mississippi 

 Valley to and beyond Texas during early, middle, and late 

 Cambrian, middle Ordovician, Niagaran, Onondagan, 

 Upper Devonian, Mississippian, and Pennsylvanian 

 times ; they show embayments occupying the lower 

 Mississippi Valley during Helderberg and Hamilton 

 times, and do not show any submergence in this part of 

 the valley during Triassic and Jurassic times. 



W. B. Scott, ^^ on his paleogeographic maps of North 

 America published in 1907, showed the lower Mississippi 

 Valley to be '4and or unknown" during Ordovician, 

 Silurian, and Upper Carboniferous times, showed that it 

 was submerged during Devonian and Lower Carbonifer- 

 ous times, and that it was land during Triassic and 

 Jurassic times. 



Bailey Willis, on his paleogeographic maps published 

 in 1909^^ and 1910,^^ designates the lower Mississippi 

 Valley as ^'Land or sea; more likely sea'' during early 

 Cambrian, Middle Ordovician, Silurian, Middle Devonian, 

 Mississippian, Pennsylvanian, latest Paleozoic, and Trias- 

 sic times. He designates it as '^Land or sea ; more likely 

 land'' during late Jurassic time, and holds that it was 

 submerged by epicontinental marine waters during ' ' Late 

 Middle and Upper Cambrian" times. 



A. W. Grabau^'^ has published maps showing the paleo- 

 geography of North America (1) at the end of ^^ Upper 

 Cambric" time, (2) in early ^^Beekmantownian" time, 

 (3) at the end of ^^Beekmantownian" time, (4) at the end 

 of Chazy time, and (5) at the end of Trenton time, and in 



^^ Cliainberlin, T. C, and Salisbury, B. D., Geology, vols. 2 and 3, Henry 

 Holt & Co., New York, 1906. 



®- Scott, W. B., An introduction to geology, The Macmillan Co., 1917. 



^ Willis, Bailey, Paleogeographic maps of North America, Jour. Geology, 

 vol. 17, 1909. 



^ Willis, Bailey and Salisbury, E. D., Outlines of Geologic history with 

 especial reference to North America, The University of Chicago Press, 1910. 



^ Grabau, A. W., Physical and f aunal evolution of North America during 

 Ordovicic, Siluric, and early Devonic time, Jour. Geology, vol. 17, pp. 209- 

 252, 1909. 



Willis, Bailey, and Salisbury, E. D., Outlines of Geologic history with 

 especial reference to North America, pp. 44-88, University of Chicago Press, 

 1910. 



