130 Canadian Record of Science. 



less ellipsoidal basins. Across the basins, though the 

 average depth has been stated to be half a degree, because 

 of the unevenness of the floor, the actual inclinations vary 

 considerably. This local variation, combined with the 

 discontinuity of the outcrops, renders exact correlation 

 exceedingly difficult, if not impossible. 



In any attempted correlation of widely separated beds 

 by aid of their inclination it must not be forgotten that 

 the beds originally existed, each as a continuous sheet 

 over large areas, in toto probably lens shaped, and not 

 only must the maximum inclination or dip be known, but 

 the inclination in the direction of the line between the 

 two beds whose correlation is attempted must be ascer- 

 tained. The evidence at present available makes even a 

 correlation of this kind in the area under discussion 

 impossible. 



With our present available knowledge it cannot be 

 proven that the limestones or argillaceous beds in the one 

 locality are synchronous or contemporaneous with the 

 sandstone in the other ; nor can it be proven that the 

 sandstones antedate the limestones, except in the few 

 places where both occur together, in which event it 

 becomes necessary to show that these limestones are also 

 younger than the sandstones elsewhere. 



To the writer the possibility that the sandstones in one 

 locality are synchronous with the argillaceous beds and 

 the limestones in another seems more plausible than that 

 they antedate them. This interpretation also obviates the 

 necessity of assuming a time interval of some duration 

 between the deposition of the sandstones and the Black 

 Eiver limestone, during which interval the Calciferous and 

 the Chazy were deposited elsewhere, and during which the 

 hon-fossiliferous beds below the Black River and above 

 the sandstone may have been deposited here. 



Were fossils present in the sandstone this possibility 

 would be in no way diminished by the fact, even were 

 some of them Potsdam forms. In the locality east of 



