LETTER OF TRANSMITTAL. 



United States Department of Agricultuee, 



Bureau of Biological Survey, 

 WasJiingtorif D. C, January 3, 1914- 

 Sir: I have the honor to transmit herewith, for pubHcation as 

 North American Fauna No. 36, the results of a study of the American 

 harvest mice by Arthur H. Howell, assistant biologist, Biological 

 Survey. 



The American harvest mice occur abundantly in or near meadows 

 and cultivated lands over a large part of the United States. Their 

 exact economic relations are still little known, but they belong to a 

 group of mammals many species of which are injurious to agriculture, 

 and there is no doubt that they consume large quantities of forage 

 and some grain. 



Up to the present time the relationships and distribution of the 

 many species have been imperfectly understood. The present report 

 furnishes for the first time a complete systematic synopsis of the 

 group, with maps showing the ranges of the species of most economic 

 importance. 



Respectfully, H. W. Henshaw, 



Chief, Biological Survey. 



Hon. David F. Houston, 



Secretary of Agriculture. 



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