936 NEW YORK STATE MUSEUM 



argillaceous slates with intercalations of thin limestone beds* 

 The latter, consisting of hard gray, very fine grained limestone, 

 are but about 1 inch thick and separated by black carbonaceous, 

 argillaceous shales. These alternations of limestone bands and 

 black, relatively soft shales, are well shown on plates 2 and 3. 

 On plate 2 also the beds of green and black slates appear dis- 

 tinctly by their different shades, and the thin bedding can be 

 noticed. The whole terrane, which by the width of the outcrop 

 might be taken to represent a considerable thickness, is appar- 

 ently nothing but a manifold repetition of the same series of 

 beds in small, closely packed, and in all conceivable ways dis- 

 torted folds. The latter appear distinctly on plate 3, which 

 shows a part of the north bank of the river. 



The lithologic similarity of the Schaghticoke beds with those 

 of the Deep kill, containing the Beekmantown-Chazy fauna, m 

 very striking; there occurring thin equally bedded, alternating,, 

 greenish and black slates and intercalated, thin, barren lime- 

 stone bands. It is evident that there was no difference or break 

 whatever in the physical conditions from the time of the depo- 

 sition of these Cambric beds to that of the Lower Siluric beds; 

 and the writer would not be surprised if in other localities they 

 should be found to form a continuous series, as indeed is 

 strongly suggested by the results of Professor Dale's investiga- 

 tion of the lithologic and stratigraphic characters of the slate 

 belt. 



Inclosed in these shales there have been found two different 

 kinds of fossiliferous beds. The one is characterized by the 

 occurrence of Dictyonema flabelliforme Eichwald, 

 the other by that of Olonograptus proximatus Mat- 

 thew. Both faunules have been observed in several places of 

 the outcrop. This is partly due to a repetition of the same beds, 

 but it is also obvious that neither of them is restricted to a 

 single band, for one bed contained prevailing grown and half 

 grown specimens of Dictyonema, while another bed, found a 

 little farther down the river, carries nothing but the earliest 

 growth stages. Likewise, at least two different beds, containing 

 the Olonograptus faunule, have been noticed. 



On account of the extremely disturbed condition of the beds, 

 I have not been able to satisfy myself as to the relative position* 



