PEEFACE. 



The number of works through which- the descriptions of 

 insects published by Say are scattered, has been a serious 

 obstacle to the progress of Entomology in the United States. 

 As the founder of that branch of science in this country, the 

 basis of all knowledge of our species rests upon a correct 

 determination of those known to him ; but the labor and 

 expense of acquiring this information is so great, in conse- 

 quence of the cost and number of the works to be consulted, 

 that it is within the power of few to possess even a moder- 

 ately complete series of his contributions. 



For the purpose of aiding the researches of the student 

 of Entomology in this country, and for the securing of due 

 credit to the labors of this great naturalist abroad, I have 

 here brought together all the descriptions of insects publish- 

 ed by him. By the introduction of the paging of the 

 original publications [in brackets] into the body of the text, 

 the labor of referring to a separate index for the place of 

 publication is obviated, and the true reference can be readily 

 made. 



With the view of increasing the usefulness of the work, 

 notes have been added, in which the species, so far as pos- 

 sible, are referred to genera adopted in the present condi- 

 tion of science. And I must here express my earnest thanks 

 to Baron R. von Osten Sacken, of the Russian Legation, at 

 "Washington, for his kindness in furnishing me with his notes 

 on the Diptera described by Say, and to Mr. Philip R. 

 Uhler for similar notes upon Orthoptera, Neuroptera and 

 Hemiptera. 



My own researches upon the Coleoptera of the United 

 States have led me to follow very nearly in the path of Say, 



