ACKNO WLE DGMENTS. 



I wish to express my indebtedness to my associates in this work for 

 much guidance and aid, both in the field and in the laboratory, and particu- 

 larly to Dr. Foerste for many suggestions and actual aid in delimiting 

 the Cambrian, Carboniferous, and igneous rocks about North Attleboro. 

 The following-named gentlemen rendered assistance at one time or another 

 during the course of the field work : C. W. Coman, U. S. G S. ; Robert 

 Wainwright, W. E. Parsons, Harry Landes, U. S. G. S.; J. Ralph Finlay, 

 U. S. G S., and G W. Tower. To Prof. J. E. Wolff my thanks are due 

 for examining many thin sections of rocks. To Prof. George H. Barton I 

 am indebted for the privilege of reading a manuscript report, with sections, 

 based upon his study of the Norfolk County Basin, and to Prof. A. S. 

 Packard, of Brown University, for the use of the collection of plants from 

 Rhode Island. All the photographs illustrating this monograph were taken 

 under my immediate supervision by Mr. Philip P. Sharpies, of Cambridge, 

 Massachusetts. 



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