760 THE PALEONTOLOGY OP MINNESOTA. 



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COMMUNICATION. 



Professor N. H. WINCHELL, Slate Geologist. 



Sm: At your request I have prepared the following chapter, embracing descriptions of the Cephalo- 

 poda of the Lower Silurian rocks of Minnesota, which is herewith respectfully transmitted. 

 I have the honor to remain, sir, 



Very truly yours, 



JOHN M. CLARKK. 

 ALBANY, N. Y., September 10, 1894. 



