DEVONIAN AND MISSISSIPPIAN FAUNAS 99 



In central New York the history is somewhat different in that the 

 Intumescens fauna does not penetrate there in its typical expression, 

 and the Ithaca beds, which are equivalent to the Portage, carry a 

 fauna which is in large part a Hamilton derivative, this being followed 

 by the Chemung fauna. Still farther east, in the same state, the Portage 

 epoch is represented by the non-marine Oneonta sandstone which is 

 followed by marine beds with a recurrent fauna, which pass upward 

 into the Chemung. In the extreme eastern portion of New York the 

 non-marine Catskill conditions were doubtless constant from the 

 beginning of the Upper Devonian until its close. 



THE INTERIOR CONTINENTAL PROVINCE 



Middle and Upper Devonian of the Interior Continental Province. 

 In passing from the Eastern Continental to the Interior Continental 

 provinces, both the stratigraphic and faunal conditions are found to 

 be totally different in almost every detail. In New York, where the 

 Middle and Upper Devonian beds of the Eastern Continental Province 

 have their most typical development, a maximum thickness of more 

 than 3,000 feet of strata is recognized, and in the Appalachians in 

 Pennsylvania the thickness is much greater, but in Iowa the total 

 thickness of the Devonian beds of the Interior Continental Province 

 is less than 300 feet. The entire series of Devonian beds in Iowa are 

 commonly referred to the Middle and Upper Devonian, the Upper 

 beds being unconformable upon the Middle,' but the limits of these 

 divisions do not correspond at all with the limits of the Middle and 

 Upper divisions of the Devonian in the Eastern Continental Province. 



In the Middle Devonian of the Iowa geologists two major divisions 

 are recognized, the Wapsipinicon and the Cedar Valley. Both the 

 Wapsipinicon and the Cedar Valley are made up of minor formational 

 units of more or less local development, and of these the Independence 

 shales occupy a position near the base of the Wapsipinicon. The fauna 

 of the Independence shales is the oldest of the Devonian faunas of 

 lowa,^ and it shows much in common with the fauna of the Lime Creek 

 shale of the Upper Devonian of the same state. 



In the Upper Devonian three formations are included in Iowa, the 

 Lime Creek shales, the State Quarry beds, and the Sweetland Creek 



I Calvin, Jour. Geol., XIV, 575; also la. Geol. Surv., XVII, 197. 

 » Calvin, Bull. U. S. Geol. Surv. Terr., IV, 725. 



