DESCRIPTION OF THE FORMATIONS. P*. 75 



600 feet above the assumed upper limit of the Chemung. 

 Its fossil contents indicate a transition state, during which 

 Chemung species yet lived, though the ground had been 

 already twice occupied by the great ganoid of the Catskill. 



It is not a question of much moment into which forma- 

 tion this fossiliferous sandstone falls. Some may prefer 

 to regard it as the top of the Chemung, others as belonging 

 to the Catskill. In regard to the former view it must be 

 stated that other fossiliferous beds occur above it to a height 

 of more than 500 feet, (see report on Penn township,) and 

 that in these beds is found a very small form of Spirifer,* 

 and the only Chemung species yet seen above the sand- 

 stone. In regard to the latter view it must be said that 

 these fossils have not previously been recognized anywhere 

 in the great mass of the red sandstone and shale comprising 

 the Catskill group. Yet, through its lower part, I have 

 found the same or kindred species ; and Prof. White has 

 also reported them from beds in other parts of the State 

 similarly situated, but ranging to nearly 2000 feet above 

 this assumed base of the Catskill. f 



Moreover, as these fossils often occur in the solid sand- 

 stone and red shale with the remains of ganoid fish, we can- 

 not assert that they are an indication of the return of Che- 

 mung conditions bringing with them Chemung species. The 

 fossils, to whichever group they are assigned, evidently 

 lived, died, and were buried in Catskill conditions and 

 among Catskill species. 



The most logical plan is to consider these strata from the 

 base of the red sandstone and shale up to the highest fos- 

 siliferous beds above mentioned, or, perhaps, even up to 

 rhe Dellville sandstone 'described below), as a series of pas- 

 beds between the Chemung and the Catskill during 

 the formation of which Catskill conditions more and more 

 prevailed, rendering the seas less and less congenial to the 

 Chemung fauna, until at length the lntter became extinct: 

 and then followed that vast accumulation of red sandstone 

 and shale almost destitnte of organic remains, except those 



* Which I consider to be .V. disjuncta. 

 t See his Reports G 5 , G«, ''~. 



