566 NEW YORK STATE MUSEUM 



along the river from Watervliet and Troy southward would have 

 to be excluded as being of Trenton age. The term would, hence, 

 become misleading. But, even if it should be desired to retain 

 it for the Lorraine and Utica zones, the objection would have to 

 be raised that these are nowhere exposed in typical sections with 

 their upper and lower boundaries and with their typical faunas 

 in the Hudson valley, while these conditions which would appear 

 absolutely necessary for the proper definition of a stratigraphic 

 term are satisfactorily fulfilled in the neighborhoods of Utica and 

 Lorraine, as shown by Walcott and Emmons. The writer holds, 

 therefore, that the term "Hudson river group" for the terranes be- 

 tween the Trenton and Medina (Oneida) formations should be 

 dropped. Clarke and Schuchert (62) have proposed the term, 

 "Cincinnatian", for this interval in the geologic time scale of 

 North America. This term has the advantage of derivation from 

 a region where not only the Utica and Lorraine beds are 

 fully developed, but where also a stage which intervenes between 

 the Lorraine and Upper Siluric age, and which is missing in New 

 York, viz the Richmond stage, is present. 



It would hardly be appropriate or practical to transfer the 

 term, "Hudson river shales", to the shales of the Normans kill or 

 Dicellograptus zone, which indeed is fully developed in the Hud- 

 son river valley and is seen there to rest on lower Trenton lime- 

 stone and to be overlaid by middle Trenton shales. As a fades 

 which faunistically and lithologically differs strongly from the 

 synchronous lower Trenton limestone, it certainly deserves to be 

 designated by a separate name. Ami used the term, "Quebec or 

 upper division of the Quebec group", for the same facies, while 

 Walcott, in the discussion following the reading of Ami's paper, 

 suggested that the term, "Quebec", be restricted to this upper 

 division alone in distinction from ^'Levis" etc. In the Quebec 

 massive the beds are cut off from the neighboring terranes by 

 faults, and their taxonomic position can not be fixed conclusively 

 by the stratigraphy of the region, but the equivalent shales of the 

 Hudson river valley are well defined in their stratigraphic posi- 

 tion. 



