494 NEW YORK STATE MUSEUM 



which has been taken up by the textbooks and has come into 

 general use. 



In the same volume Hall described some new graptolites from 

 the Point L6vi& shales of Canada as coming from near the sum- 

 mit of the Hudson river group (p. 503), a correlation to which 

 exception was taken by Billings (9), who not only claimed a 

 greater age for the Point L^vis and Quebec, but also for the 

 Normans kill graptolites. Billings derives his conclusion from 

 a comparison with the vertical range of the graptolites in Eng- 

 land, a proceeding which, 25 years later, was repeated by Lap- 

 worth and, interestingly enough, with similar results. This 

 paper of Billings's is indicative of the complete change in the 

 correlation of the Hudson river shales which, about this time, 

 was wrought by the influence of the Canadian survey. The latter, 

 Influenced by the presence of primordial fossils in the Hudson 

 valley region, assumed that the older rocks of Canada and of the 

 Champlain valley extended into the Hudson valley. The influ- 

 ence of Emmons, who had extended the term, Taconic, to the 

 shales of the Hudson valley and asserted the continuation of the 

 Hudson river shales to the primordial region of Quebec, was also 

 powerful in shaping Hall's view of the older Lower Siluric age 

 of the Hudson river shales. When Hall received the graptolites 

 of the Canadian survey for description, and believed that he recog- 

 nized in species from Point Levis and other localities on the 

 St Lawrence below Quebec, Normans kill species, he came out 

 openly (10) for the " primordial (Quebec) age " of the bulk of 

 the Hudson river beds, assuming with Logan, that the two or 

 three occurrences of a few fossils of the " second fauna " were 

 ^' outliers of insignificant extent embraced within the folds of 

 the older rooks or resting upon these primordial beds which 

 formed the fundamental rocks of the valley, and that the de- 

 raiuged and altered Hudson river beds were separated from the 

 unaltered beds in the west by a fault ". He, therefore, dropped 

 the term Hudson river group, stating expressly (10:444) that 

 the graptolites of the Hudson valley do not belong to the second 

 fauna, but " hold a lower position and belong to the great mass 

 of the shales below". ^ ' ' jl 



