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trative material in the form of rock collections, maps, and models, 

 particularly in Course 8. 



The Commonwealth of Massachusetts has called on the Pro- 

 fessor of Geology for service in three boards : the Commissioners 

 of the Topographical Survey, the Commissioners of Highways, 

 and a committee of the State Board of Agriculture charged with 

 the extermination of the Ocneria dispar, or Gypsy Moth. These 

 duties have demanded a considerable part of his time, and have 

 necessarily diminished the amount of research work which should 

 otherwise have been done. He has also been much engaged in 

 supervising and directing the work of several assistants in the 

 Atlantic Coast division of the United States Geological Survey. 



