Ii6 STUART WELLER 



the Maxville limestone, whose fauna is to be correlated essentially 

 with the Ste. Genevieve of southern Illinois and Missouri. It has been 

 shown by Stevenson' that only the upper portion of the Pocono is of 

 Mississippian age, and that this part is stratigraphicaly continuous 

 with the Waverly group of Ohio. The basal member of the Waverly 

 group, in the more general application of that term, is the Bedford 

 shale in which occurs a fauna with Hamilton affinities.^ As has 

 already been pointed out, this fauna is believed to be associated with 

 the incursion of the Hamilton-like forms which constitute one element 

 in the southern Kinderhook faunas. The composition of the succeed- 

 ing Waverly faunas has been more carefully studied by Herrick^ than 

 by anyone else, and they exhibit throughout more or less affinity with 

 the Kinderhook faunas of the Mississippi Valley Basin. Numerous 

 members of the fauna suggest a Devonian derivation sometimes from 

 Hamilton and sometimes from Chemung progenitors, as if they were 

 to some extent a mingling of the two Kinderhook faunas of the Missis- 

 sippi Valley. These Waverly faunas are, however, in no wise to be 

 considered as contemporaneous with the Kinderhook alone of the 

 Mississippi Valley, but they must also represent the Osage. In the 

 Appalachian Basin, with its continuity of clastic sedimentation, 

 environmental conditions similar to those of the Kinderhook persisted 

 through Osage time, consequently there is no sharp differentiation of 

 the faunas as there was in the Mississippi Valley where the period of 

 clastic sedimentation was displaced by the clear seas in which nothing 

 but calcareous sediments were deposited. For this reason the typical 

 Burlington and Keokuk faunas do not occur in the Appalachian Basin, 

 but an occasional member of these faunas found its way into the basin 

 and such forms left records which are of value in the correlation of 

 the faunas. 



Outside of Ohio little or no detailed faunal study of these beds has 

 been made, but Stevenson^ has pointed out the stratigraphic correla- 

 tion of the beds throughout the Appalachian Basin from Pennsylvania 

 to Alabama. 



1 Loc. cit. 



2 Herrick, Geol. Surv. Ohio, VII, 507. 



3 A summary of Herrick's work is to be found in Geol Surv. Ohio, VII, 495-515. 



4 Loc. cit. 



