PEEFACE. 



It is a gratifying fact that the science of entomology is making 

 rapid progress in our country, and that so much has already been 

 accomplished by industrious students. There is an increasing 

 demand for books on this subject, but as yet none has been pub- 

 lished professing to describe all the species of any one order 

 of our insects. Admirable monographs of some families and 

 genera of Coleoptera have been published by Dr. Leconte and 

 others, and of our Sphingidre by Drs. Harris and Clemens. Other 

 entomologists, as Say, Melsheimer, Peale, Fitch, Ziegler, Halde- 

 man, Uhler, and a few others, have contributed essentially to the 

 discrimination of the species of various orders, but thus far no 

 more comprehensive work has been attempted. Dr. Harris's inval- 

 uable book on the insects of New England injurious to vegetation, 

 approaches the nearest to such a work of any that have appeared 

 in our country. The splendid and costly volume of Boisduval and 

 Leconte on our diurnal butterflies, published in Paris, 1833, has 

 never been finished, and contains but twenty-one genera and nine- 

 ty-three species. Foreign naturalists have described hundreds of 

 our species, but their descriptions are scattered through a number 

 of journals and other works not easily accessible to the American 

 student. 



I have attempted in this work to bring together in as narrow a 

 compass as possible all our described Lepidoptera, embracing the 

 llhopalocera and the first two tribes of the Heterocera. Thus all 

 our known diurnals, Sphinges and Bombyces, are included, down to 

 the Noctuidoe proper. The latter will probably be taken up at some 

 future time. I have collected the descriptions from many different 

 authors, to whom due credit is given, but I have omitted some of 

 the references to books, having given them in full in my catalogue 



