284 C. R. KEYES DEVONIAN INTERVAL IN MISSOURI 



(Chouteau limestone) was in no way connected with that of the lower 

 Kinderhook, but was inseparably connected with the higher or Burling- 

 ton faunas. This last-mentioned fauna was, then, the fauna which 

 Meek and Worthen* had partially studied, and, without any attempt to 

 investigate thoroughly, had assumed as extending unbroken through 

 the entire section of their Kinderhook formation. 



Other phases of the problem brought out by the results of the exam- 

 ination of the Louisiana section were presented in some notes f on the 

 ta Relations of the Devonian and Carboniferous in the Upper Mississippi 

 valley." The conclusions reached may be briefly stated as follows : 



(1) The most marked changes in the succession of faunas in the 

 entire sequence of rocks commonly known as the Lower Carboniferous 

 or " Subcarboniferous," as represented along the Mississippi river, is at 

 the base of the Chouteau limestone (limited). At this horizon there is 

 so great a faunal break that scarcely a species is common to the beds 

 on either side. 



(2) That instead of the so-called Kinderhook containing in its fauna 

 a mingling of Devonian and Carboniferous types, there are really two 

 great faunas that are perfectly distinct and well defined, and do not 

 merge into each other. In general aspects, the one is characteristically 

 Devonian ; the other strikingly Carboniferous. 



(3) The basal line of the Lower Carboniferous, or Mississippian, series 

 is the base of the Chouteau limestone, and the lowest member of the 

 four-fold series contains only one formation, instead of three, heretofore 

 commonly ascribed to it. 



(4) The early reference of a part of the so-called Kinderhook, or 

 u Chemung," to the Devonian was correct in fact, though made entirely 

 through erroneous correlations and a misconception of the real facts. 



(5) That the evidence afforded by the faunas of the region is in 

 close accord with the facts obtained regarding discordant sedimenta- 

 tion and the stratigraphical and lithological characters of the formations 

 themselves. 



AFFINITIES OF THE LOWER KINDERHOOK FA UNA 



So far as go the somewhat limited observations on the fossils of the 

 Grassy Creek shales, their fauna appears to be identical with that of the 

 lower Kinderhook at Louisiana. The prolifically fossiliferous layers of 

 the Louisiana limestone are the shales separating the limestone layers 

 at the very base of the formation. These shale partings, if they may be 

 so called, are the same in all observable respects as the Grassy Creek 



*Am. Jour. Sci. (2), vol. xxxii, 1861, p. 167. 



f Trans. St. Louis Aead. Sci., vol. vii, 1897, p. 357. 



