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oder Naturbeschreibung der Zerkarien und Bazillarien 1817, by P. 

 A. C. Nitzsch. This seems to be the habitat of the Bacillaria and 

 the cold temperature of 32° F., o° C, of the glacier and they appa- 

 rently carne from the worth, and when the glacier breaks up and 

 what we may cali spring comes it appears there at first as the iceberg 

 period and the water which is cold collects in lakes on the borders 

 of the ice and forms what is known as « Kettle Iloles» und Kettlc 

 Holes seem to be the receptacle of Bacillaria in the form of the 

 wellknown « infusorial earth ». This is mostly siliceous but some- 

 times contains any silica. It is commonly clay. This clay is deposited 

 as the ice melted and constitutes what are known as « sub-peat », 

 a lacustrine sedimentary », and « fresh water deposits » so common 

 now at Cherryfield, Maine, at Bowkerville (which is the same as 

 Keene), New Hampshire, at West Point, New York and at Wee- 

 quahick Lake, New Jersey, besides others. 



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