392, WW. M. Dawis—Nonconformity at Rondout. 
The interruptions in the sequence of formations at Rondout 
are of two kinds. One, that may be called passive, consisted 
essentially in withholding the supply of sedimentary material, 
so that certain epochs were left unrepresented: thus the 
Medina, Clinton and Schoharie deposits are completely want- 
ing, and the Oneida and Niagara are almost absent. The other 
interruption came between the deposition of the Hudson River 
and the Coralline or 
Fig. 1. 
; verlooking Ro 
out (at Section II) where the contact line has been perfectly 
exposed for ten feet or more; a fair inference of nonconformity - 
