l62 NEW YORK STATE MUSEUM 



stages of the Eodevonic the direction of migration was from the north inward 

 and southward. Reference has been made to the occurrence of the Eode- 

 vonic on St Helens island, Montreal and to the presumption that it indi- 

 cates the remnant of a backset along the St Lawrence trough of these 

 waters, rather than any connection with New York through the Champlain 

 trough. We find no reason for modifying this view as there is no single 

 factor which presumes a paleozoic water connection along the Champlain 

 graben during a period so late as the Devonic. 



14 The Gaspe sandstones indicate (as we have suggested) a general 

 breaking down of the barriers of the northern channel, by a transgression 

 over the Silurian beds adjoining and a widening out of the area in such a 

 way as to constitute in large part flood deposit or barachois conditions 

 throughout the eastern part of the- Gaspe peninsula. These conditions 

 continued throughout the Middle Devonic as shown by the notable per- 

 centage of New York Hamilton species in these rocks commingled with 

 highly typical survivors of the earlier or Grande Greve fauna. The New 

 York species are here clearly the invaders, having entered this province by 

 the still open waterway from the southwest. The remains themselves, 

 whether of Grande Greve or Hamilton species, we regard as overwashed 

 into their present position from outside the barrier bounding the barachois 

 and not native to the sandy terrigenous sediments, abounding in plant 

 remains, with which the)- are associated. 



The numerical predominance of species in this fauna which can not be 

 distinguished from those of Middle Devonic in the Appalachian gulf, seems 

 to justify the interpretation given above, though the suggestion is not 

 wanting that those species are allied to certain Coblentzian elements which 

 bear close comparison with the New York Hamilton fauna I have had 

 occasion to intimate that migration southwestward and westward from the 

 German Coblentzian basin is adequate to explain the occurrence in later 

 beds of certain of those species, and this proposition makes large demand 

 for time lost in migration from east to west and would not, I judge, in view of 

 the stratigraphy of the overlying conformable mass of Bonaventure deposits, 

 material!)' alter the construction of the age of the Gaspe sandstone fauna. 



