58 THE ICE AGE IN CANADA. 



and the estuaries opening into it from the portions of the 

 land still above water are not uncommon. Of this nature 

 are the beds at Pakenham, examined by the late Sheriff 

 Dickson, and which, as I was informed by him, are 

 arranged as follows : 



Feet. Inches. 



Sand and surface soil about 10 



Clay 10 



Fine gray sand (shells of Valvata, &c. ) . . . . 2 



Clay 1 



Gray sand, laminated (7W^ma (T/^ee??ZawfZ«ca) 3 



Clay 8 



Light gray sand ( Valvata, Gyclas, Paludina, 



Planorhis and Tellina) 10 



Clay 1 2 



Brown sand and layers of clay [Planorhis 



and Cyclas 4 



The fresh water species are peculiar to this locality, 

 and the only marine shell is Tellina Grcenlanclica, a species 

 now found farther up in our estuaries than most others. 



Mr. Dickson informs me that a similar case occurs near 

 Clarenceville, about four miles from the United States 

 frontier, and at an elevation of about ten feet above lake 

 Champlain. Specimens from this place contain large 

 shells of Unio rectus and U ventricosits, the latter with the 

 valves cohering, and a Lymnea. Intimately mixed with 

 these in sandy clay are valves of Tellina Grcenlandica and 

 Mya arenaria. 



I record these facts, without pledging myself to the 

 conclusion that these deposits really mark the margins or 

 river estuaries of the old Pleistocene of Canada, though 

 they will certainly bear that interpretation. In farther 

 connection with these facts, and in relation also to the 

 question why marine fossils have not been found west of 

 Kingston, Mr. Dickson informs me that fossil capelin are 



